WO2006068142A1

WO2006068142A1 - Gas detection sensor and gas detector

Info

Publication number: WO2006068142A1
Application number: PCT/JP2005/023370
Authority: WO
Inventors: Osamu Yamada; Kouichi Hiranaka; Takeshi Hatakeyama
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2004-12-21
Filing date: 2005-12-20
Publication date: 2006-06-29

Abstract

Disclosed is a gas detection sensor comprising a strip-shaped resistive layer having a certain resistance which is provided with electrodes at both ends, a detection film which is arranged in contact with at least one side of the resistive layer extending in the longitudinal direction and the electrical characteristics of which vary when it comes into contact with a detection object gas, and a common electrode which is arranged in contact with the detection film and joined to the resistive layer via the detection film. The detection film is arranged to be exposed in the longitudinal direction.

Description

Specification

Gas detection sensor and gas detection device

Technical field

TECHNICAL FIELD [0001] The present invention relates to a gas detection sensor and a gas detection device that are used in equipment and piping for flammable gas such as hydrogen gas and detect a gas leakage point.

Background art

[0002] In recent years, from the viewpoint of protecting the global environment and preventing fossil fuels from drying out, it is desired to use clean and recyclable energy. Among such energies, research to use hydrogen gas as an energy source has been actively conducted, centering on fuel cells. In order to disseminate hydrogen gas as an energy source, hydrogen gas, which has an explosive limit concentration range of 4% to 75%, is easy to handle in hydrogen storage and transportation, and is safe from hydrogen leakage. Ensuring is an essential condition. In order to ensure safety, it is essential to install a gas detection sensor to detect hydrogen gas leakage.

[0003] As a conventional gas detection sensor, a catalytic combustion type or semiconductor type hydrogen gas detection sensor is mainly used.

In a catalytic combustion type hydrogen gas detection sensor, a catalytic metal such as platinum (Pt) or palladium (Pd) is heated by a heater, and the hydrogen gas in contact with the catalyst is oxidized by oxygen in the air. The catalytic combustion type hydrogen gas detection sensor electrically detects heat generated by the oxidation of hydrogen gas as a change in the conductivity of the catalyst metal.

[0004] On the other hand, the semiconductor-type hydrogen gas detection sensor detects a change in electrical characteristics of the detection film due to adsorption of hydrogen gas to the detection film, that is, a change in the resistance value of the detection film. This semiconductor type hydrogen gas detection sensor is used in a state heated by a heater, like the contact combustion type hydrogen gas detection sensor. Examples of this are disclosed, for example, in Japanese Utility Model Publication No. 49-23507 (pages 1-3) and Japanese Patent Application Laid-Open No. 7-260727.

[0005] These hydrogen gas detection sensors are used for fuel cell vehicles and stationary fuels that use hydrogen gas. It is used as a hydrogen gas detection sensor for detecting hydrogen gas leaks in hydrogen batteries such as fuel cells, hydrogen dispensers and hydrogen compressors, and gas storage facilities such as hydrogen cylinders. For example, when used in a fuel cell vehicle, a plurality of fuel cell vehicles are installed near the fuel cell stack, near the hydrogen tank, inside the vehicle cabin roof, etc., where hydrogen gas is likely to leak or where it is likely to stay. Such an example is disclosed, for example, in Japanese Unexamined Patent Publication No. 2004-2 3874 (pages 5-8, FIG. 3). Also, in hydrogen equipment such as hydrogen dispensers and hydrogen compressors, the location where hydrogen gas inside the equipment is likely to leak or where it is likely to stay, the upper part of the room where these hydrogen equipment is installed, the vicinity of the exhaust port, etc. A plurality of hydrogen gas detection sensors are installed at locations where hydrogen gas exhaust passages are likely to stay. Recently, a hydrogen gas detection sensor using an optical fiber has been proposed as a new hydrogen gas detection sensor. Such an optical fiber type hydrogen gas detection sensor is formed by forming a detection film whose refractive index changes with respect to light when hydrogen is detected in the cladding portion of the optical fiber. This optical fiber type hydrogen gas detection sensor detects the concentration of hydrogen gas on a line along the optical fiber laying line. This optical fiber type hydrogen gas detection sensor does not measure the hydrogen gas concentration at the point where the sensor is installed like the conventional catalytic combustion type or semiconductor type hydrogen gas detection sensor, but lays an optical fiber. One-dimensional hydrogen gas concentration can be measured on the line. Furthermore, this optical fiber type hydrogen gas detection sensor measures the position where hydrogen gas is detected on the optical fiber by combining optical time domain reflectometry (OTDR) technology. It is also possible. Such an example is disclosed, for example, in Japanese Unexamined Patent Publication No. 2003-166938 (page 3-6, FIG. 3).

Patent Document 1: Japanese Utility Model Publication No. 49-23507 (Pages 1-3)

Patent Document 2: JP-A-7-260727

Patent Document 3: Japanese Patent Laid-Open No. 2004-23874 (Pages 5-8, Fig. 3)

Patent Document 4: Japanese Patent Laid-Open No. 2003-166938 (page 3-6, Fig. 3)

Disclosure of the invention

Problems to be solved by the invention [0007] However, the conventional hydrogen gas detection sensor of the catalytic combustion system, the semiconductor system, and the optical fiber system has the following problems.

As described above, the catalytic combustion type and semiconductor type hydrogen gas detection sensors detect the hydrogen gas concentration at the installed location. For this reason, the hydrogen gas leaked by the hydrogen gas detection sensor may not be detected depending on the direction and speed of the air flow between the location where the hydrogen gas leaks and the location where the hydrogen gas detection sensor is installed. Therefore, in order to increase the certainty, it is necessary to set the detection sensitivity of the hydrogen gas detection sensor high. However, increasing the detection sensitivity in this way has caused problems such as malfunctions caused by gases other than hydrogen gas and failures due to changes over time.

[0008] Hydrogen gas leakage generation force The detection time until it is detected by the hydrogen gas detection sensor includes the hydrogen gas leakage location, the hydrogen gas outflow direction from the leakage location, and the air flow around the leakage location. Fluctuates greatly depending on conditions. In particular, there is a risk that a large amount of hydrogen gas has already leaked when the hydrogen gas sensor detects the leaked hydrogen gas in a gas storage chamber that stores a large amount of hydrogen gas. Therefore, reducing detection time is an important issue in this area.

[0009] In addition, in order to detect the exact position of the hydrogen gas leak location, it is necessary for humans to perform an inspection operation to search for hydrogen gas leaked using a portable hydrogen gas detector. In such a human inspection work, in a large-scale hydrogen device or plant, the number of inspection points is enormous, and the inspection takes time, and the risk increases.

An optical fiber type hydrogen gas detection sensor is different from the conventional hydrogen gas detection sensor in that the hydrogen gas generated in the area where the optical fiber is installed is not detected only at the installation location. It is a sensor that can detect leakage of water. As described above, the optical fiber type hydrogen gas detection sensor can detect the position where hydrogen gas is detected on the laying line of the optical fiber when combined with the OTDR technology. As described above, the optical fiber type hydrogen gas detection sensor is expected as a new hydrogen gas detection sensor that can solve the problems of the conventional hydrogen gas detection sensor.

[0010] However, the position detection accuracy in the hydrogen gas detection sensor of an optical fiber type is expensive. Even using OTDR, it was not possible to make it less than several tens of centimeters, and it was difficult to identify the leak location. For this reason, in order to accurately detect the leak position of hydrogen gas, it was eventually necessary to perform a human inspection using a portable hydrogen gas detector. In addition, the optical fiber used in the optical fiber type hydrogen gas detection sensor itself was broken and difficult to handle immediately.

Means for solving the problem

[0011] In order to solve the above problems, a gas detection sensor according to the present invention includes a substantially strip-shaped resistance layer having a predetermined resistance value,

A first electrode and a second electrode electrically connected to both ends in the longitudinal direction of the resistive layer, and arranged so as to contact along the longitudinal direction on at least one of the longitudinal surfaces of the resistive layer; A sensing film made of a material whose electrical characteristics change upon contact with the gas to be sensed, and

A common electrode disposed in contact with at least one surface in the longitudinal direction of the detection film and bonded to the resistance layer via the detection film;

The detection film is configured to be linearly exposed along the longitudinal direction.

[0012] A gas detection sensor according to another aspect of the present invention includes a substantially planar resistance layer having a predetermined resistance value,

A first electrode, a second electrode, a third electrode, and a fourth electrode electrically connected to four ends of the resistance layer;

A sensing film made of a material that is laminated so as to be in contact with one surface of the resistance layer and whose electrical characteristics change by contact with the gas to be sensed; and

A common electrode formed of a conductor and laminated on the resistance layer via the sensing film;

The detection film is configured to be exposed in a planar shape.

[0013] The gas detection device according to the present invention includes a detection film formed of a material whose electrical characteristics change by contact with the gas to be detected, and the detection surface is configured in a substantially band shape. Detection Gas detection sensor that outputs a current divided according to the gas detection position when detecting gas, Bias power supply that supplies power to the gas detection sensor, An arithmetic unit for calculating a gas detection position by performing arithmetic processing on the current-divided signal of the gas detection sensor force

The computing unit subtracts the signal when the gas detection target gas divided by the gas detection sensor force is not detected and the signal when it is detected, and adds the subtraction result to the calculation result and the division process It is configured to detect the gas detection position based on the calculated result

[0014] A gas detection device according to another aspect of the present invention includes a detection film formed of a material whose electrical characteristics change by contact with a gas to be detected, and the detection surface is configured to have a substantially planar shape. A gas detection sensor that outputs a current divided into four directions according to the gas detection position when a gas to be detected is detected,

A bias power supply for supplying power to the gas detection sensor;

An arithmetic unit for calculating a gas detection position by performing arithmetic processing on the current-divided signal of the gas detection sensor force

The computing unit subtracts the signal when the gas detection target gas divided by the gas detection sensor force is not detected and the signal when detected, and adds the subtraction result to the calculation result and the subtraction process. It is configured to detect the gas detection position based on the calculated result

[0015] A gas detection device according to still another aspect of the present invention is a gas detection device having a gas detection sensor that changes resistance when a gas to be detected is detected,

A sensing film formed in a substantially belt-like shape,

A resistive layer bonded and stacked on one surface of the detection film in the longitudinal direction, and bonded and stacked on another surface of the detection film in the longitudinal direction, and a predetermined bias voltage is applied to the detection film. A common electrode for applying, and

A first electrode and a second electrode that are not bonded to the detection film and are formed at both ends in the longitudinal direction on the resistance layer;

Each resistance value change between the common electrode and the first electrode and between the common electrode and the second electrode is measured via the resistance layer, and based on the resistance value change, The gas detection position is configured to be calculated. [0016] A gas detection device according to still another aspect of the present invention is an electrically insulating base material formed in a substantially strip shape,

A resistance layer formed by bonding to the longitudinal surface of the substrate;

A sensing film that is laminated on a longitudinal surface of the resistance layer and changes its resistance when a gas to be detected is detected;

A common electrode formed on a longitudinal surface of the sensing film for applying a predetermined bias voltage to the sensing film; and

A first electrode and a second electrode provided at both ends of the resistance layer to detect a resistance change of the sensing film;

A resistance value change between the common electrode and the first electrode and a resistance value change between the common electrode and the second electrode are measured via the resistance layer, and the resistance value change is determined based on each resistance value change. V. The gas detection position of the detection film is calculated.

[0017] A gas detector according to still another aspect of the present invention is an electrically insulating base material formed in a substantially strip shape,

A common electrode formed by bonding to the longitudinal surface of the substrate;

A sensing film that is laminated on the longitudinal surface of the common electrode and changes its resistance when a gas to be detected is detected,

A resistance layer laminated on a longitudinal surface of the sensing film; and

A predetermined bias voltage is applied to the detection film via the common electrode, a resistance value change between the common electrode and the first electrode, and the common electrode and the second electrode via the resistance layer. A change in resistance value is measured, and a gas detection position of the detection film is calculated based on each change in resistance value.

[0018] A gas detection device according to still another aspect of the present invention is a gas detection device having a gas detection sensor that changes resistance when a gas to be detected is detected,

A sensing film formed in a substantially belt-like shape,

A resistance layer laminated and bonded to one surface of the longitudinal surface of the sensing film; A common electrode for applying a predetermined bias voltage to the detection film, laminated and bonded to another surface in the longitudinal direction of the detection film;

A first electrode and a second electrode which are not joined to the sensing film and are formed at both ends in the longitudinal direction on the resistance layer; and

Conversion means for calculating a gas detection position by detecting a resistance change between the common electrode and the first electrode and a resistance change between the common electrode and the second electrode;

The converting means converts a current value flowing between the common electrode and the first electrode through the resistance layer and a current value flowing between the common electrode and the second electrode into a voltage value. In other words, an arithmetic unit that calculates a gas detection position based on the converted voltage value is provided.

[0019] A gas detection device according to still another aspect of the present invention is a gas detection device having a gas detection sensor that changes resistance when a combustible gas is detected,

A sensing film formed in a substantially belt-like shape,

The temperature of the detection film is heated to 200 ° C. and 400 ° C., and between the common electrode and the first electrode and between the common electrode and the second electrode through the resistance layer. Each resistance value change is measured, and the gas detection position of the detection film is calculated based on the resistance value change.

[0020] A gas detection device according to still another aspect of the present invention is a gas detection device having a gas detection sensor that changes resistance when a gas to be detected is detected,

A detection film having a film surface formed in a substantially rectangular shape and disposed so as to include the X direction and the Y direction in which the film surfaces are orthogonal to each other;

A rectangular resistive layer laminated on one side of the sensing film;

A common electrode that is formed in contact with the other surface of the detection film and applies a predetermined bias voltage to the detection film; A linear first electrode and a second electrode provided on a pair of opposing sides of the resistance layer and extending in the X direction to detect a gas detection position in the X direction; and

Provided on the other pair of opposing sides of the resistance layer, and includes linear third electrodes and fourth electrodes extending in the Y direction to detect the gas detection position in the Y direction! /

[0021] A gas detection device according to still another aspect of the present invention is a gas detection device having a gas detection sensor that changes resistance when a combustible gas is detected,

A rectangular resistive layer laminated on one side of the sensing film;

A common electrode that is formed in contact with the other surface of the detection film and applies a predetermined bias voltage to the detection film;

A linear first electrode and a second electrode provided on a pair of opposing sides of the resistance layer and extending in the X direction to detect a gas detection position in the X direction;

A third linear electrode and a fourth electrode, which are provided on the other pair of opposing sides of the resistance layer and extend in the Y direction to detect a gas detection position in the Y direction; and

Heating means for heating the temperature of the detection film to a temperature of 200 ° C and 400 ° C

[0022] A gas detection device according to still another aspect of the present invention is a gas detection device having a gas detection sensor whose electrical resistance changes when a gas to be detected is detected,

A base material formed in a substantially strip shape and having electrical insulation,

A common electrode formed on the long side of the longitudinal surface of the substrate;

A plurality of predetermined regions are configured by detection films arranged linearly with a predetermined interval, and one end of each detection film is connected to the common electrode; and

A detection electrode connected to the other end of the detection film of the sensor cell and configured to form a pair with the common electrode;

A bias voltage is applied to the common electrode, a resistance value change between the common electrode and the detection electrode is detected, and a gas detection position is calculated based on the position of the sensor cell where the resistance value change is detected. It is configured as follows. [0023] A gas detection device according to still another aspect of the present invention is a gas detection device having a gas detection sensor having a detection film whose electrical resistance changes when a gas to be detected comes into contact with the gas detection device, and has electrical insulation properties. A substrate formed by a material having a substantially strip shape and penetrated by a plurality of holes arranged linearly at a predetermined interval;

A sensor cell having a detection film formed on the inner surface of the hole of the substrate;

A common electrode formed on one longitudinal surface of the substrate and connected to one end of each of the sensing films; and

A plurality of detection electrodes formed on the other surface of each of the detection film parts, and formed on the other surface of the base material in pairs with the common electrode;

A bias voltage is applied to the common electrode, a change in resistance value between the common electrode and the detection electrode of the sensor cell is detected, and a gas detection position is calculated based on the position of the sensor cell where the change in resistance value is detected. It is configured to

[0024] A gas detection device according to still another aspect of the present invention is a gas detection device having a gas detection sensor having a detection film whose electrical resistance changes when a gas to be detected is detected, and is electrically insulating. A substrate formed by a material having a substantially rectangular shape and penetrated by a plurality of holes arranged at predetermined grid-intersection positions at a predetermined pitch,

A plurality of sensor cells having a detection film formed on the inner surface of the hole of the base material, formed on one rectangular surface of the base material, connected to one end of each of the sensor cells, and applied with a predetermined bias voltage A common detection electrode in the column direction indicated by the Xi (i = l to m) electrode,

Yj (j = l to n) electrodes formed on the other rectangular surface of the substrate, connected to the other ends of the sensor cells, and paired with the Xi electrodes in the common detection electrodes in the column direction. A common detection electrode in the row direction,

A noise voltage is supplied to the sensor cell through the Xi electrode at a predetermined time interval, a change in resistance value between the Xi electrode and the Yj electrode to which the bias voltage is supplied is detected, and the resistance value change is detected. The gas detection position is calculated based on the position of the sensor cell where the gas is detected.

The invention's effect [0025] According to the present invention, a gas leakage sensor in a one-dimensional or two-dimensional gas detection region can be configured with a simple configuration by using a gas detection sensor and a gas detection device with a simple configuration for the leakage portion of the gas to be detected. It has an excellent effect that it can be reliably detected. Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a schematic configuration of a hydrogen gas detection sensor of Example 1 according to the present invention.

FIG. 2 is a plan view showing the planar shapes of three types of common electrodes 1 in Example 1. FIG.

FIG. 3 is a cross-sectional view showing another configuration of the hydrogen gas detection sensor of the present invention.

FIG. 4 is a cross-sectional view showing still another configuration of the hydrogen gas detection sensor of the present invention.

FIG. 5 is a cross-sectional view taken along the line V—V in the hydrogen gas detection sensor of FIG.

FIG. 6 is a perspective view showing another configuration of the hydrogen gas detection sensor of Example 1 according to the present invention.

FIG. 7 is a block diagram showing a configuration of an arithmetic unit and the like in the first embodiment according to the present invention.

FIG. 8 is a graph showing the relationship between hydrogen gas detection position X and calculation result E2.

FIG. 9 is a graph showing the relationship between hydrogen gas volume concentration and calculation result E1.

FIG. 10 is a cross-sectional view showing a configuration of a hydrogen gas detection sensor of Example 2 according to the present invention.

FIG. 11 is a plan view showing a detection surface of the hydrogen gas detection sensor according to Example 2 of the present invention.

[FIG. 12] FIG. 12 is a drawing explaining the effect of the through hole in the hydrogen gas detection sensor of Example 2.

FIG. 13 is a graph showing the relationship between the hydrogen gas volume concentration and the calculation result E1 in the hydrogen gas detection sensor of Example 2.

FIG. 14 is a cross-sectional view showing a configuration of a hydrogen gas detection sensor of Example 3 according to the present invention.

FIG. 15 is a graph showing experimental results in the configuration of Example 3 according to the present invention.

FIG. 16 is a graph showing experimental results in the configuration of Example 3 according to the present invention. FIG. 17 is an exploded perspective view showing a schematic configuration of the hydrogen gas detection sensor according to the fourth embodiment of the present invention.

FIG. 18 is a plan view showing the shape of a common electrode in the hydrogen gas detection sensor of Example 4.

FIG. 19 is a cross-sectional view showing a laminated structure of the hydrogen gas detection sensor of Example 4.

FIG. 20 is a cross-sectional view showing a laminated structure of the hydrogen gas detection sensor of Example 4.

FIG. 21 is a block diagram showing a configuration of a hydrogen gas detection sensor and a computing unit of the fourth embodiment.

FIG. 22 is a graph showing the relationship between the hydrogen gas detection position and the calculation result in the hydrogen gas detection sensor of Example 4.

FIG. 23 is a graph showing the relationship between the hydrogen gas volume concentration and the calculation results in the hydrogen gas detection sensor of Example 4.

24] FIG. 24 is a cross-sectional view showing a laminated structure of the hydrogen gas detection sensor of Example 5 according to the present invention.

FIG. 25 is a plan view of the hydrogen gas detection sensor of Example 5.

FIG. 26 is a graph showing the relationship between the hydrogen gas detection position and the calculation result in the hydrogen gas detection sensor of Example 5.

FIG. 27 is a graph showing the relationship between the hydrogen gas volume concentration and the calculation results in the hydrogen gas detection sensor of Example 5.

28] FIG. 28 is a sectional view showing a laminated structure of the hydrogen gas detection sensor according to the sixth embodiment of the present invention.

FIG. 29 is a graph showing the relationship between the surface temperature of the detection film and the response time in the hydrogen gas detection sensor of Example 6.

FIG. 30 is a graph showing the relationship between the surface temperature of the detection film and the calculation results in the hydrogen gas detection sensor of Example 6.

[FIG. 31] FIG. 31 shows a one-dimensional array type hydrogen gas detection sensor of Example 7, (a) is a plan view of the hydrogen gas detection sensor, and (b) is a W—W line in (a). (C) is a rear view of the hydrogen gas detection sensor. FIG. 32 is a block diagram showing a configuration of a gas detection device according to Embodiment 7 of the present invention.

FIG. 33 is a diagram for explaining an experiment of a one-dimensional array type hydrogen gas detection sensor in Example 7.

FIG. 34 is a plan view (a) and a sectional view (b) showing another configuration of the one-dimensional arrangement type hydrogen gas detection sensor of the seventh embodiment.

FIG. 35 is a block diagram showing another configuration of the gas detection device according to Embodiment 7 of the present invention.

FIG. 36 is a block diagram showing the configuration of the gas detector of the eighth embodiment according to the present invention.

FIG. 37 is a view showing the structure of a two-dimensional array type hydrogen gas detection sensor according to Example 9 of the present invention, (a) is a plan view, and (b) is a hydrogen gas detection sensor of (a). FIG. 6 is a cross-sectional view taken along line Y—Y in the sensor.

FIG. 38 is a block diagram showing a configuration of a gas detection device in Example 9.

FIG. 39 is a diagram for explaining an experiment of a two-dimensional array type hydrogen gas detection sensor in Example 9.

FIG. 40 is a diagram showing a different configuration of the hydrogen gas detection sensor of Example 9.

FIG. 41 is a block diagram showing a configuration of a gas detection device according to Example 10 of the present invention.

Explanation of symbols

1 Common electrode

2 electrodes

3 electrodes

4 Resistance layer

5 Sensing membrane

6 Base material

8 Detector

24 Leader 26 Hydrogen gas

27 Bias power supply

29 Current limiting resistor

81 Rand

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of a gas detection sensor and a gas detection device according to the present invention will be described in detail with reference to the accompanying drawings.

Example 1

[0029] The gas detection sensor according to the first embodiment of the present invention has a substantially linear (one-dimensional) hydrogen gas detection in which the gas detection region capable of detecting hydrogen gas contained in the gas to be detected is one-dimensional. This is a hydrogen gas detection sensor with a surface. Hereinafter, the hydrogen gas detection sensor of Example 1 will be described with reference to FIGS.

[0030] First, a schematic configuration of the hydrogen gas detection sensor of Example 1 will be described with reference to FIG. FIG. 1 is a cross-sectional view showing a schematic configuration of the hydrogen gas detection sensor of the first embodiment. In FIG. 1, dimensions such as the thickness of each element are exaggerated for easy explanation, and are different from actual ones.

In the hydrogen gas detection sensor 25 of Example 1 shown in FIG. 1, the resistance layer 4, the detection film 5, and the common electrode 1 are laminated on the upper surface of the substrate 6. The common electrode 1 is formed on a part of the upper surface of the detection film 5 so that the gas to be detected is in contact with the detection film 5. The common electrode 1 may be configured to cover the entire detection film 5 so that hydrogen gas contained in the gas to be detected can pass through the common electrode 1 and contact the detection film 5. At both ends of the resistance layer 4, electrodes 1 and 2 are provided as a first electrode and a second electrode. Lands 81 and 81 to which a bias power supply 27 is connected are formed at both ends of the common electrode 1.

As shown in FIG. 1, when hydrogen gas 26 contained in the gas to be detected is generated at the detection position X, the hydrogen gas 26 comes into contact with the detection film 5 at the detection position X. In contact with hydrogen gas, the sensing film 5 is substantially insulative and has a high resistance value in a non-detected state. When the detection film 5 comes into contact with the hydrogen gas 26, the detection part 8 of the detection film 5 that is the contact portion becomes a semiconductor. The semiconductor detection unit 8 has a lower electrical resistance value. As a result, the current from the bias power supply 27 connected to the common electrode 1 passes through the semiconductor detection unit 8 and is divided into currents in the resistance layer 4. The current divided current is output via electrode 2 and electrode 3. By calculating the relative values of the currents output from the electrodes 2 and 3 output at this time, it is possible to detect the hydrogen gas detection position and the hydrogen gas concentration on the detection film 5.

Next, the structure of the hydrogen gas detection sensor 25 of Example 1 in which the hydrogen gas detection region is one-dimensional will be described in detail with reference to FIG.

In the hydrogen gas detection sensor 25 of Example 1, the base material 6 has a substantially band shape, and quartz (SiO 2), which is an electrically insulating material, is used. The detection surface side of this substrate 6 (the top in Fig. 1)

2

A pair of electrodes composed of an electrode 2 and an electrode 3 are formed at both ends of the side. Further, a substantially strip-shaped resistive layer 4 made of tantalum nitride (TaN) is formed on the detection surface side (upper side) of the base material 6 so as to cover a part of the electrodes 2 and 3. A lead wire 24 formed of copper (Cu) is connected to each of the electrodes 2 and 3, and the lead wire 24 is connected to a computing unit 28 (see FIG. 7) described later via the lead wire 24. On the detection surface side (upper side) of the resistance layer 4, when hydrogen gas is detected, the state changes from an insulating state to a semiconductor state, and the resistance value of the electrical characteristics decreases, and the platinum dispersion supported tungsten trioxide (Pt—WO)

The sensing film 5 formed in 3 is provided. The detection film 5 has a substantially band shape and is formed so as to cover the resistance layer 4. In addition, a pair of lands 81 made of gold (Au) are formed on the detection surface side of both ends of the detection film 5. The lands 81 are formed at positions corresponding to the electrodes 2 and 3 on both ends of the resistance layer 4, that is, substantially immediately above the electrodes 2 and 3 with the detection film 5 in between. A common electrode 1 made of gold (Au) is formed on the detection film 5, and the pair of left and right lands 81 are electrically connected by this common electrode 1. A lead wire 24 made of copper (Cu) is connected to the land 81, and the land 81 is connected to the bias power source 27 through a current limiting resistor 29. The land 81 is provided to connect the lead wire 24 to the common electrode 1. Therefore, in the configuration in which the common electrode 1 and the lead wire 24 are directly connected, it is not necessary to provide a land.

[0034] The hydrogen gas detection sensor 25 of Example 1 has a one-dimensional hydrogen gas detection region, and a substantially strip-shaped detection film 5 formed on the upper part of the resistance layer 4 that connects between the electrodes 2 and 3. Hydrogen gas It is the structure which detects. The hydrogen gas detection sensor 25 according to the first embodiment is configured to detect a position where the hydrogen gas contacts when a part of the substantially band-shaped detection film 5 contacts the hydrogen gas. In the hydrogen gas detection sensor 25, the range between the electrode 2 and the electrode 3 at both ends of the resistance layer 4 is set as a detection range, and the detection length in the detection range is set to L (see FIG. 1).

As shown in FIG. 1, the common electrode 1 in the hydrogen gas detection sensor 25 of Example 1 is formed so as to cover the detection range of the detection film 5. However, the detection film 5 has a structure that can be exposed to the gas to be detected.

[0035] FIGS. 2A, 2B, and 2C are plan views showing the planar shape of the common electrode 1, and show the structures of the three types of common electrodes 1. FIG. In any of the configurations (a), (b), and (c) of FIG. 2, the common electrode 1 is formed on the sensing film 5 between the electrodes 2 and 3, and the sensing film 5 is covered. It has a gap 99 so that it can be exposed to the detection gas. The common electrode 1 shown in FIG. 2 (a) is formed in a lattice shape, and a rectangular gap 99 is formed. In the common electrode 1 shown in FIG. 2 (b), a circular gap 99 is formed. The common electrode 1 shown in (c) of FIG. 2 is formed in a thin, strip-like shape extending in the longitudinal direction on the upper surface, which is the detection surface of the detection film 5, and slits on both sides of the common electrode 1. A gap 99 is formed. As described above, the common electrode 1 shown in FIGS. 2 (a), (b) and (c) has the gap 99 in any configuration, and the detection film 5 is directly exposed to the gas to be detected. Is the structure. As for the arrangement of the gap 99 configured as described above, it is desirable that the arrangement region of the detection film 5 exposed to the gas to be detected is distributed almost uniformly over the entire detection surface! /, .

Hereinafter, the common electrode 1 shown in FIGS. 2A, 2B, and 2C will be described in more detail.

The common electrode 1 shown in FIG. 2 (a) is configured to have a lattice-like mesh, and has a rectangular gap 99. The common electrode 1 is formed so as to electrically connect lands 81 and 81 provided on both sides of the hydrogen gas detection sensor 25. Therefore, the part other than the mesh of the common electrode 1, that is, the gap 99 is exposed so that the detection film 5 under the common electrode 1 is exposed to the gas to be detected. The mesh shape of the common electrode 1 is almost the same in the detection range. Mesh spacing in the detection direction, which is the longitudinal direction of the common electrode 1 It is desirable that the hydrogen gas contained in the gas to be detected is shorter than the range in which the hydrogen gas contacts the detection film 5. In general, it is desirable that the length of the hydrogen gas jet point force detection film 5 is sufficiently shorter than the length.

[0037] FIG. 2 (b) shows the common electrode 1 provided with a gap 99 which is a plurality of circular holes.

The common electrode 1 is formed so as to electrically connect the lands 81 and 81 provided on both sides of the hydrogen gas detection sensor 25, and the detection film 5 on the lower side of the common electrode 1 is formed into hydrogen gas. A plurality of voids 99 are formed so as to be exposed. Therefore, the hole portion of the gap 99 is a portion where the detection film 5 can be exposed to hydrogen gas. The shape of the hole in the gap 99 is almost the same in the detection range. Further, the holes are arranged at equal intervals in the longitudinal direction of the common electrode 1, and are arranged with substantially the same length in the detection range. This interval is desirably sufficiently shorter than the range in which the hydrogen gas contained in the gas to be detected contacts the detection film 5. In general, it is desirable that the hole interval be sufficiently shorter than the length from the hydrogen gas ejection point to the detection film 5.

FIG. 2 (c) shows a configuration in which a linear common electrode 1 is formed between lands 81 provided on both sides of the hydrogen gas detection sensor 25. The common electrode 1 shown in FIG. 2 (c) is a linear electrode composed of an electrically connected film body, and electrically connects the land 81 on both sides of the hydrogen gas detection sensor 25. is doing. Moreover, it is desirable that the width of the common electrode 1 that is linear is substantially the same in the detection range. Further, in FIG. 2C, the number of force common electrodes 1 shown in the example in which only one common electrode 1 is formed on the upper surface of the detection film 5 may be plural. In that case, it is desirable that the distance between the common electrodes 1 is substantially the same in the detection range.

In the gas detection sensor of the present invention, the means for exposing the detection film 5 to the gas to be detected is not limited to the configuration shown in (a) to (c) of FIG. Materials that are permeable to hydrogen gas contained in the detection gas, such as metal thin films of 1 μm or less, such as gold (Au), silver (Ag), and copper (Cu), and sintered materials It is also possible to use a porous conductor or the like.

As described above, the basic structure of the hydrogen gas detection sensor in Example 1 is the detection film 5 formed in a substantially strip shape, and the substantially strip-shaped resistance layer 4 formed on one surface in the longitudinal direction of the detection film 5. And formed on the other surface of the detection film in the longitudinal direction so as not to be in electrical contact with the resistance layer 4 The common electrode 1 is formed.

[0040] Next, the resistance value between the electrodes 2 and 3 (hereinafter referred to as interelectrode resistance) provided at both ends of the resistance layer 4 and the detection film 5 detect hydrogen gas contained in the gas to be detected. The resistance value between the common electrode 1 and the electrode 2 (hereinafter referred to as junction resistance) and the resistance value between the common electrode 1 and the electrode 3 (hereinafter referred to as junction resistance) in the undetected state and the detected state Explain the relationship.

As shown in FIG. 1, when a noise power source 27 is connected to the common electrode 1 through the current limiting resistor 29, the common electrode 1 and the electrode 2 are connected between the common electrode 1 and the electrode 2 when the detection film 5 is not detecting hydrogen gas. In addition, a current (hereinafter referred to as a bias current) that is inversely proportional to the combined resistance of the current limiting resistor 29 and the junction resistance flows between the common electrode 1 and the electrode 3.

[0041] When the sensing film 5 is exposed to hydrogen gas, the exposed part of the sensing film 5 is made into a semiconductor, and the current flowing between the common electrode 1 and the electrode 2 and between the common electrode 1 and the electrode 3 Will increase. Based on this increased current value, it is possible to detect the position where the detection film 5 is semiconductive and the concentration of hydrogen gas. Therefore, if the bias current is greater than the amount of current that increases due to the detection film 5 detecting hydrogen gas, the sensitivity and resolution, so-called hydrogen gas detection, are affected by changes in the bias current. The SZN ratio of the sensor decreases. Therefore, it is desirable to set the joint resistance to a value higher than the interelectrode resistance. The value of the junction resistance should be set at least about 1 times or more than the value of the interelectrode resistance, preferably 10 times or more, more preferably 100 times or more.

[0042] In a hydrogen gas detection sensor having a one-dimensional hydrogen gas detection region, when the detection range is increased, the interelectrode resistance increases while the junction resistance decreases. Therefore, as described below, it is desirable to adjust the shape and film thickness of the common electrode 1, the resistance layer 4, and the sensing film 5 to improve the ratio of the junction resistance and the interelectrode resistance.

In order to increase the junction resistance between the common electrode 1 and each of the electrodes 2 and 3, the contact area between the common electrode 1 and the detection film 5 is decreased, or the contact area between the resistance layer 4 and the detection film 5 It is necessary to increase the thickness of the sensing film 5 or the force to decrease Further, the interelectrode resistance between the electrode 2 and the electrode 3 can be reduced by increasing the thickness of the resistance layer 4. As a hydrogen gas detection sensor according to the present invention in which the hydrogen gas detection region is one-dimensional, In addition to the configurations shown in FIGS. 1 and 2, there is a hydrogen gas detection sensor having the following configuration. In the following description, components having the same function and configuration are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 3 is a cross-sectional view showing another configuration of the hydrogen gas detection sensor of the present invention, and shows a hydrogen gas detection sensor having a one-dimensional hydrogen gas detection region. The hydrogen gas detection sensor shown in FIG. 3 is configured by laminating a common electrode 1, a substantially strip-shaped detection film 5, and a substantially strip-shaped resistance layer 4 in this order on a substrate 6. Electrodes 2 and 3 are provided on both ends of the resistance layer 4. The uppermost resistive layer 4 shown in FIG. 3 has a lattice shape (see (a) in FIG. 2), similar to the shape of the common electrode 1 shown in FIGS. 2 (a) to (c). It has a shape with holes (see (b) in Fig. 2) or a line (see (c) in Fig. 2). Therefore, the detection film 5 under the resistance layer 4 has a structure that can be exposed to the gas to be detected. In the hydrogen gas detection sensor shown in FIG. 3, the detection range is between electrodes 2 and 3 indicated by length L in FIG.

In the structure of the hydrogen gas detection sensor shown in FIG. 3, the uppermost resistive layer 4 has a gap 99 as in the shape of the common electrode 1 shown in (a) to (c) of FIG. Even if it has a structure, it is sufficient that the resistance layer 4 is made of a material having hydrogen gas permeability. For example, the resistance layer 4 may be a thin film such as tantalum nitride (TaN) or acid-chromium (CrO) formed at a low density.

2

It is also possible to use a sintered porous material such as a metal oxide.

FIG. 4 is a cross-sectional view showing still another configuration of the hydrogen gas detection sensor of the present invention, and shows a hydrogen gas detection sensor having a one-dimensional hydrogen gas detection region. The hydrogen gas detection sensor shown in FIG. 4 has a configuration in which the base material 6 is not specially provided. That is, the common electrode 1 has a function as a base material. FIG. 5 is a cross-sectional view taken along the line V-V in the hydrogen gas detection sensor of FIG.

[0046] In the hydrogen gas detection sensor shown in Fig. 4, the sintering temperature of detection film 5 with high conductivity such as copper (Cu), stainless steel! ^), Aluminum (A1), etc. is about 500 ° C. The common electrode 1, which is a substantially strip-shaped metal foil that is sufficiently stable, is used as a base material. On the common electrode 1, a substantially strip-shaped detection film 5 and a substantially strip-shaped resistance layer 4 are sequentially laminated. Electrodes 2 and 3 are provided on both ends of the resistance layer 4. In this hydrogen gas detection sensor Similarly to the hydrogen gas detection sensor shown in FIG. 3, the resistance layer 4 has the same shape as that of the common electrode 1 shown in (a), (b) or (c) of FIG. Alternatively, when the resistance layer 4 is formed on the entire detection surface of the detection film 5, the resistance layer 4 is formed using a material having hydrogen gas permeability.

The hydrogen gas detection sensor shown in FIG. 4 has the shape of the gap 99 shown in (c) of FIG. 2, as shown in the sectional view of FIG. That is, the hydrogen gas detection sensor in FIG. 4 has a configuration in which a linear detection film 5 is exposed on both sides of the resistance layer 4, and the resistance layer 4 is formed in a one-dimensional gas detection region in the center of the detection film 5. It is formed in a band shape along. The hydrogen gas sensor configured in this way has a thickness of 0.05m as the common electrode 1! By using a metal foil with a foldable characteristic of about 2 mm, it is possible to realize a flexible shape characteristic that can be bent.

FIG. 6 is a perspective view showing a hydrogen gas detection sensor having still another configuration according to the present invention, and shows a hydrogen gas detection sensor having a one-dimensional hydrogen gas detection region. The hydrogen gas detection sensor shown in FIG. 6 has a structure in which a common electrode 1, a detection film 5, and a resistance layer 4 are formed on the surface on the detection surface side of a long and narrow strip-shaped base material 6.

As shown in FIG. 6, a substantially strip-shaped common electrode 1 and a substantially strip-shaped resistance layer 4 are formed in parallel with each other at a predetermined interval on one surface (detection surface side) of the substrate 6. Yes. The detection film 5 is formed on the base 6 between the common electrode 1 and the resistance layer 4, and the detection film 5 and the common electrode 1 are in contact with each other along the longitudinal direction, and the detection film 5 and the resistance layer are in contact with each other. 4 is configured to contact along the longitudinal direction. In the hydrogen gas detection sensor of FIG. 6, the electrode 2 and the electrode 3 are formed at both ends of the resistance layer 4. In the configuration shown in FIG. 6, the sensing film 5 does not need to be configured in the shape shown in (a) to (c) of FIG. It is a configuration that is exposed.

[0049] [Material for hydrogen gas detection sensor]

Next, materials for the hydrogen gas detection sensor according to the present invention will be described in detail. The material of the base material 6 is electrically insulative and stable at a heating temperature of 500 ° C. when the detection film 5 is sintered. Any state can be used. Concrete material of base material 6 is stone In addition to UK (SiO 2), silicon (SiO 2) and aluminum nitride (A

twenty two

Insulating materials such as IN) and alumina (A120) can be used. In addition, greaves material and

Three

For example, a heat-resistant phenolic material such as Timold made by Nikko Kasei Co., Ltd. can be used. In this case, it is also possible to obtain a three-dimensional shape other than a plane by using an injection molding method. Further, as the flexible sheet-like material, for example, a polyimide material such as Kapton (registered trademark) of Toray DuPont Co., Ltd. can be used. Polyimide-based materials have a maximum heat-resistant temperature of about 450 ° C, but can be used by performing the sintering temperature of the detection film 5 at about 450 ° C.

[0050] As the resistance layer 4, a thin film resistor formed by vapor deposition or the like, a thick film resistor formed by sintering after printing, or the like can be used. In particular, a thin film resistor formed by vapor deposition or the like is desirable because it is easy to form the detection film 5 having a uniform film thickness on the resistance layer 4 where the surface roughness of the resistance layer is small. Thin film resistor materials include single metals such as tantalum (Ta), nickel chrome (NiCr), nickel chrome 'silicon alloy (NiCr—Si), tantalum' silicon alloy (Ta—Si), niobium 'silicon alloy. Alloy thin films such as (Nb—Si), cermet thin films such as chrome 'acid silicon (Cr-SiO 2), tantalum' silicon oxide (Ta—SiO 2), ruthenium oxide

twenty two

(RuO 2), chromium oxide (Cr 2 O 3), tantalum nitride (TaN), or the like can be used.

2 2 3

[0051] Electrode 2 serving as the first electrode and electrode 3 serving as the second electrode are materials having high conductivity and are stable at about 500 ° C, which is the sintering temperature of the detection film 5. Can be used. It is more desirable that the electrode itself is inert to the combustible gas containing hydrogen atoms in the gas to be detected. Electrodes 2 and 3 are made of highly conductive materials such as magnesium (Mg), aluminum (A1), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), and nickel (Ni). Metal such as silver (Ag) or carbon (C) can be used. In particular, the materials for electrodes 2 and 3 are preferably gold (Au) or copper (Cu), which is inert to hydrogen gas that is difficult to oxidize.

[0052] As the detection film 5, any substance can be used as long as it has a property of changing electrical resistance when it comes into contact with the gas to be detected. For example, tin oxide (SnO), molybdenum trioxide

2

Ribden (MnO), tungsten trioxide (WO), titanium dioxide (TiO), iridium hydroxide

2 3 2

Um (Ir (OH) n), vanadium pentoxide (VO), rhodium oxide (Rh O · χΗ Ο), etc. It is possible that

The common electrode 1 is a highly conductive material, and it is more desirable that the electrode itself be inert to the hydrogen gas in the gas to be detected. Common electrode 1 materials are magnesium (Mg), aluminum (A1), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), nickel (Ni), which are highly conductive materials. Metal such as silver (Ag), carbon (C), etc. can be used. In particular, the material for the common electrode 1 is preferably gold (Au) or copper (Cu), which is inert to hydrogen gas that is difficult to oxidize.

[0053] [Operation principle of hydrogen gas detection sensor]

Next, the operation principle of hydrogen gas detection of the hydrogen gas detection sensor of Example 1 according to the present invention will be described.

In Fig. 1, the case where the hydrogen gas 26 contained in the gas to be detected contacts the detection film 5 formed of tungsten trioxide supported by platinum dispersion at the position indicated by the arrow A! To do. This platinum-dispersed supported tungsten trioxide is dispersed on platinum (Pt) fine particles having a particle size of about lnm to lOnm as a catalyst and dispersed on tungsten trioxide (WO) particles having a particle size of about lOnm to lOOnm. It has a supported structure. Hydrogen gas is platinum (Pt) fine

Three

Dissociated into protons (H +) and electrons (e ^_ ) on the particle. The dissociated protons (H +) spill over from the platinum catalyst fine particles and diffuse into tungsten trioxide (WO), which is the main component of the detection film 5, to form tungsten bronzes. Tungsten trioxide (WO)

3 3 Nungsten bronze is formed, and the state is close to electrical insulation. However, tungsten trioxide (WO) diffuses protons (H +)

Three

The formation of the Lons makes it a semiconductor, and the concentration of hydrogen gas increases and many protons (

When H +) diffuses, it becomes a property close to a conductor from a semiconductor.

On the other hand, the current generated from the noise power source 27 connected to the common electrode 1 flows intensively through the detection unit 8 made semiconductor. The current flowing through the detection unit 8 flows from the detection unit 8 through the resistance layer 4 and is divided into currents 2 and 3. The current flowing through the resistance layer 4 is divided into currents in inverse proportion to the ratio of the distances Xa and Xb to the electrode 2 and the electrode 3, and the output of the electrode 2 and the electrode 3 is output.

Next, the current signals output from the electrodes 2 and 3 of the hydrogen gas detection sensor 25 are The operation of the computing unit 28, which is a conversion means for converting into a voltage signal, will be described with reference to FIG. FIG. 7 is a block diagram illustrating a configuration of the computing unit 28 to which a signal from the hydrogen gas detection sensor 25 of the first embodiment is input. As shown in FIG. 7, the gas detection device of the first embodiment includes a hydrogen gas detection sensor 25, a bias power source 27, a computing unit 28, and a current limiting resistor 29.

As described above, in the hydrogen gas detection sensor 25 of the first embodiment, the exposed portion of the detection film 5 that has detected the hydrogen gas is the detection unit 8 that is made into a semiconductor. In order to detect the position of the detection unit 8 on the detection film 5, the resistance change of the detection unit 8 is converted into a current value using the resistance layer 4 and input to the calculator 28. In the arithmetic unit 28, the current value is converted into a voltage value, and the arithmetic processing is performed. The operation of the arithmetic unit 28 as the conversion means will be described below.

As shown in FIG. 7, the common electrode 1 of the hydrogen gas detection sensor 25 is connected to a bias power source 27 via a current limiting resistor 29. When the detection film 5 is in contact with hydrogen gas, the current flowing between the common electrode 1 and the electrode 2 when the hydrogen gas detection sensor 25 is not detecting hydrogen gas is the bias current Ilb, common. The current flowing between electrode 1 and electrode 3 is referred to as bias current I2b. These bias currents lib and I2b are input to the calculator 28 from the electrodes 2 and 3, respectively, and are converted into voltage signals in a current-voltage conversion circuit including the operational amplifier 14a and the operational amplifier 14b. The converted voltage signals are sent to analog-digital conversion elements 15a and 15b, which are converted into digital signals. Furthermore, each converted digital signal is sent to a divider 16 and an adder 17. The divider 16 and the adder 17 hold each digital signal in a state where no hydrogen gas is detected as a value corresponding to the bias current lib, I2b.

Next, the case where the hydrogen gas detection sensor of Example 1 has detected hydrogen gas, that is, the detection film 5 is in contact with hydrogen gas will be described.

The current flowing between the common electrode 1 and the electrode 2 when the detection film 25 detects hydrogen gas is II, and the current flowing between the common electrode 1 and the electrode 3 is 12. Similarly to the bias currents I lb and I2b described above, the currents II and 12 are input to the calculator 28 from the electrodes 2 and 3, respectively, and converted into voltage signals in the current-voltage conversion circuit described above. The converted voltage signal is sent to the analog-digital conversion elements 15a and 15b. And is sent to a divider 16 and an adder 17. In the adder 17 and the divider 16, the digital signals corresponding to the held bias currents Ila and I2b are subtracted from the digital signal forces corresponding to the currents II and 12 when hydrogen gas is detected, respectively. In addition, addition and division calculation processes shown in Equation 1 and Equation 2 described later are performed. The divider 16 and the adder 17 output the result of the division and addition operation processing to the digital / analog conversion elements 18a and 18b as digital electric signals. The digital-to-analog conversion element 18a outputs a calculation result E2 by division with an analog electric signal. The digital-to-analog conversion element 18b outputs a calculation result E1 by addition with an analog electric signal.

[0057] The above calculation results E1 and E2 are calculated by the following equations (1) and (2).

[0058] El = k20 X {(ll—lib) + (12—I2b)} (1)

[0059] E2 = k4 X (12— I2b) / {(I1— lib) + (12— I2b)}

(2)

In equations (1) and (2), k20 and k4 are constants.

In Equation (2), in the hydrogen gas detection sensor shown in FIG. 1, the calculation result E2 is 0 when the detection position is X = 0, and the calculation result E2 is 1 when X = L. Here, X = 0 is the position of one boundary portion of the detection range in the configuration shown in FIG. Therefore, X = L is the position where the detection unit 8 is close to the electrode 3 and the other boundary portion of the detection range L.

[0061] When the detection position force of hydrogen gas changes from X = 0 to X = L, the relationship between the detection position X of hydrogen gas and the calculation result E is almost linear as shown by the vertical and horizontal axis graphs. It is a relationship expressed.

In the hydrogen gas detection sensor according to the first embodiment of the present invention, the calculation process is not limited to the above formulas (1) and (2), and calculation is also performed using other formulas. be able to.

In the following, an arithmetic expression indicating the hydrogen gas detection position X other than the arithmetic processing of Expression (2) will be described.

If the expression contains a term that represents the ratio of (II 1 lib) and (12—I2b), it will be detected. It can be used as an arithmetic expression for calculating the position X. An example of a calculation method showing the specific hydrogen gas detection position X is described below.

The following formula (3) is obtained from the hydrogen gas detection sensor 25 of Example 1 shown in FIG. 1 where the calculation result E is 0 when the detection position force = 0, and the calculation result E is ∞ when X = L. This is an arithmetic expression. The relationship between the detection position X and the calculation result E shown in Equation (3) is not a relationship represented by a straight line when shown on the vertical and horizontal graphs.

[0063] E = k5 X (12—I2b) / (I1—lib) (3)

[0064] In addition, in the hydrogen gas detection sensor of Example 1 shown in FIG. 1, the following formula (4) is calculated when the detection position force ¾ = 0, and the calculation result E is -1 and when X = L: The calculation result E is 1. In the calculation of equation (4), when the detection position force of hydrogen gas changes from X = 0 to L, the relationship between the detection position X and the calculation result E is almost as shown by the graphs on the vertical and horizontal axes. Represented by a straight line.

[0065] E = k6 X [{(12— I2b) (II— lib)} /

{(II— Ilb) + (I2— I2b)}] (4)

[0066] In the above formulas (2), (3), and (4), when the detection film 5 is in contact with hydrogen gas, that is, when hydrogen gas is detected, current II and 12 force bias current lib and 12 If the value is large enough for b, it can be calculated ignoring the noise currents lib and I2b. In that case, Equation (2), Equation (3), and Equation (4) are as shown in Equation (5), Equation (6), and Equation (7) below.

[0067] E = kl X I2 / (11 +12) (5)

[0068] E = k2 X I2 / ll (6)

[0069] E = k3 X (12— II) / (II +12) (7)

[0070] As described above, the hydrogen gas detection position X of the hydrogen gas detection sensor 25 of the first embodiment in which the hydrogen gas detection region is one-dimensional is calculated by the equation (2), the force equation (7). Can be obtained.

Although the bias power source 27 used in the hydrogen gas detection sensor 25 of Example 1 has been described as a DC power source, the bias power source in the gas detection sensor of the present invention is not limited to a DC power source. 0. Also used in an AC power source of about IKHz to ΙΟΚΗζ be able to. In that case, It is necessary to add a rectification function to the current-voltage converter of the arithmetic unit 28.

In addition, the arithmetic unit 28 in the first embodiment converts the output current from the hydrogen gas detection sensor 25 into a digital signal and performs arithmetic processing. It is also possible to do.

[0071] [Experimental result of hydrogen gas detection sensor]

Experimental results of the hydrogen gas detection sensor and gas detection device of Example 1 according to the present invention will be described with reference to FIGS.

First, the hydrogen gas detection sensor with a one-dimensional hydrogen gas detection region used in this experiment will be described.

The hydrogen gas detection sensor with a one-dimensional hydrogen gas detection region used in this experiment had a detection range L of 100 mm in length and 3 mm in width. The substrate 6 was made of quartz (SiO 2) having a length of 104 mm, a width of 3 mm, and a thickness of 1 mm. Electrode 2 and electrode 3 are gold (Au)

2

Was formed at a thickness of 0.5 / z m on 2 mm on both sides of the substrate 6 by sputtering. The resistance layer 4 was formed by tantalum nitride (TaN) by a reactive sputtering method at a central portion of 102 mm and a thickness of 10 m, except for a region having a width of 1 mm from both edges of the substrate 6.

Next, a detection film 5 made of platinum dispersion-supported tungsten trioxide (Pt—WO 3) was formed.

Three

A sol-gel method was used as a forming method. Specifically, first, sodium tungstate hydrate (Na WO 2Η Η: manufactured by Junsei Chemical Co., Ltd.) 41. 2 g was placed in a volumetric flask,

2 4 2

Pure water was added to prepare 250 mL, and a 0.5 mol ZL colorless and transparent sodium tungstate (Na 2 WO 3) aqueous solution was obtained.

twenty four

[0073] Next, cation exchange resin (Amberlite IR120B Na: manufactured by Organo Co., Ltd.) was filled into a column tower, and a sodium tungstate (Na 2 WO) aqueous solution was passed through the column tower.

twenty four

The sodium ion (Na +) in the sodium acid (Na WO) aqueous solution is exchanged for protons (H +)

twenty four

A yellow tungstic acid (H 2 WO 3) aqueous solution was obtained. Tungstic acid (H WO) aqueous solution 13

2 4 2 4 mL of catalyst metal hexacloplatinic acid (H PtCl 6Η Ο: Wako Pure Chemical Industries, Ltd.

2 6 2

4 mL of an aqueous solution in which 0.5 molZL was dissolved in pure water and 8 mL of ethanol were uniformly dispersed and mixed to synthesize a sol-gel solution of platinum-dispersed tungsten oxide. The sol-gel solution is uniformly dropped on the resistance layer 4 so as to cover the entire surface, and the sol The gel solution was applied. Then, after drying at room temperature for 1 hour, using an electric furnace, pre-baking was carried out at 200 ° C. for 1 hour, followed by baking at 500 ° C. for 1 hour and then cooling at room temperature. At this time, the thickness of the detection film 5 was 1 μm.

[0074] Next, a common electrode 1 made of gold (Au) was formed using a sputter method and a metal mask. The common electrode 1 is made of gold (Au) having a linear shape as shown in FIG. 2 (c) and has a width of 0.3 mm. Only formed. Further, as shown in FIG. 2 (c), lands 81, 81 for the common electrode 1 having a width of 2 mm were formed on both sides of the detection surface of the detection film 5. The thickness of the common electrode 1 was controlled by controlling the sputtering time and sputtering power, and was 2 m in this experiment.

After the formation of common electrode 1, the junction resistances of common electrode 1 and electrode 2 and common electrode 1 and electrode 3 were measured. Each junction resistance was about 80 kΩ. The interelectrode resistance between electrode 2 and electrode 3 was about 75Ω.

[0075] Evaluation was performed under the following conditions. In the hydrogen gas detection sensor 25 of Example 1 having a one-dimensional hydrogen gas detection area and configured as described above, a DC voltage of 5 V was applied to the common electrode 1 from the bias power source 27. The current limiting resistor is 10ΚΩ. The bias current from electrodes 2 and 3 was about 60 μΑ. A circular nozzle with a gas outlet diameter of lmm was used at the location where the gas to be detected including hydrogen gas was jetted, and the jet direction was upward. The experiment was conducted with the hydrogen gas detection sensor 25 installed at a distance of lmm and 3 mm above the gas outlet.

[0076] FIG. 8 shows the case where the distance to the detection film 5 of the hydrogen gas detection sensor 25 is 1 mm and the volume concentration of hydrogen gas of the detected gas is 0.1% and 1%. 4 is a graph showing the hydrogen gas detection position X, which is the position of the nozzle gas outlet, and the calculation result E2 shown in the above equation (2). In the graph of FIG. 8, the horizontal axis is the hydrogen gas detection position X [mm], and the vertical axis is the calculation result E2. In FIG. 8, the solid line 33 indicates the case where the volume concentration of hydrogen gas is 0.1%, and the broken line 34 indicates the case where the volume concentration of hydrogen gas is 1.0%. The constant k4 in equation (2) is calculated as 1. Also, the hydrogen gas detection position X on the horizontal axis is the value of the detection position X shown in Fig. 1 and was measured from 20 mm to 80 mm.

As shown in the graph of Fig. 8, the calculation result E2 depends on the volume concentration of hydrogen gas to be detected. In addition, the hydrogen gas detection position is shown, and it was confirmed that the hydrogen gas detection area 25 is a one-dimensional hydrogen gas detection sensor 25 and a gas detection device.

[0077] The graph shown in FIG. 9 is for the case where the distance from the gas outlet of the nozzle to the detection film 5 of the hydrogen gas detection sensor 25 is 1 mm and 3 mm, and the hydrogen gas detection position X is the center of the detection film 5 (X = 50 mm). FIG. 9 shows the calculation result E1 according to the above equation (1) when the volume concentration of hydrogen gas in the gas to be detected is changed from 0% force to 1%. In the graph of Fig. 9, the horizontal axis indicates the hydrogen gas volume concentration [%], and the vertical axis indicates the calculation result E1 by addition. In FIG. 9, the solid line 35 shows the case where the distance from the gas outlet to the detection film 5 is lmm, and the broken line 36 shows the case where the distance from the gas outlet to the detection film 5 is 3 mm. The constant k20 in the equation (1) is calculated as 1 × 10 ² (V / A).

[0078] As shown in FIG. 9, in both cases where the distance indicated by the solid line 35 is lmm and the distance force S indicated by the broken line 36 is 3 mm, the calculation result E1 increases as the hydrogen gas volume concentration increases. It is rising. However, there is a difference in the calculation result E1 due to the distance to the detection film 5 for the gas ejection loca. This is because the area of hydrogen gas contacting the detection film 5 increases as the distance to the detection film 5 becomes longer, and the range of the detection part 8 made into a semiconductor becomes wider. It can be inferred that the current passing therethrough has increased. From these results, it is possible to measure the volume concentration of hydrogen gas in the gas to be detected by measuring the calculation result E1 by making the distance to the gas ejection locus detection film 5 constant.

Example 2

Hereinafter, a hydrogen gas detection sensor of Example 2 according to the present invention will be described with reference to FIGS. 10 and 11. In the second embodiment, components having the same configuration and function as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

FIG. 10 is a cross-sectional view showing the configuration of the hydrogen gas detection sensor according to the second embodiment of the present invention, and shows an example in which hydrogen gas 26 is detected at the position indicated by arrow A. As shown in the cross-sectional view of FIG. 10, the hydrogen gas detection sensor of Example 2 has a structure in which a through hole 23 penetrating from the detection film 5 to the substrate 6 is formed in the hydrogen gas detection sensor of Example 1 described above. Have The through-hole 23 has a function of allowing the gas to be detected including the hydrogen gas 26 in contact with the detection film 5 to pass from the detection film 5 through the base material 6 to the outside of the hydrogen gas detection sensor. That is, the through hole 23 This is to prevent the gas to be detected from staying on the detection film 5 and diffusing.

[0080] When the through hole 23 is not formed, the hydrogen gas 26 diffuses on the detection film 5 after contacting the detection film 5, and the contact range with the detection film 5 is expanded. However, when the through hole 23 is formed, the hydrogen gas 26 comes into contact with the detection film 5 and is then released from the base material 6 through the through hole 23. Therefore, the hydrogen gas is difficult to diffuse on the detection film. The contact area with the membrane 5 is unlikely to be widened. If the hydrogen gas 26 leaks upward by installing a hydrogen gas detection sensor so that the detection surface of the detection film 5 faces downward, the specific gravity of the hydrogen gas is very light. Most of the hydrogen gas 26 passed through the through-hole 23 is released above the hydrogen gas detection sensor, and most of the hydrogen gas does not diffuse on the detection film 5.

FIG. 11 is a plan view showing a detection surface of the hydrogen gas detection sensor according to the second embodiment. As shown in FIG. 11, the through hole 23 is formed in a portion where the detection film 5 is exposed. Further, the common electrode 1 in the hydrogen gas detection sensor of Example 2 has the shape shown in FIG. 2C, but may be formed in other shapes. Further, the through hole 23 can be provided in a portion other than the detection film 5, for example, the common electrode 1 or the land 81. However, when it is provided on the common electrode 1 or the land 81, it is necessary to form each part of the common electrode 1 and the land 81 so that an electrical connection state is maintained so as to perform the function.

[0082] [Experimental result of hydrogen gas detection sensor]

Experimental results of the hydrogen gas detection sensor and the gas detection device of Example 2 according to the present invention will be described with reference to FIGS. FIG. 12 and FIG. 13 show the effect of preventing the hydrogen gas from staying with the presence or absence of the through hole 23 in the hydrogen gas detection sensor.

The hydrogen gas detection sensor with a one-dimensional hydrogen gas detection area used in this experiment had a detection length L of 100 mm and a width of 3 mm. The substrate 6 was made of quartz (SiO 2) having a length of 104 mm, a width of 3 mm, and a thickness of 1 mm. Electrode 2

2

The electrode 3 was formed by depositing gold (Au) with a thickness of 0.5 m on 2 mm on both sides of the substrate 6 by sputtering. The resistance layer 4 was formed by tantalum nitride (TaN) by a reactive sputtering method at a central portion with a thickness of 102 μm and a thickness of 10 μm except for a region having a width of 1 mm from both edges of the substrate 6.

[0083] The detection film 5 in Example 2 is the same as the method described in the experiment of Example 1 described above. Formed by the method. That is, the detection film 5 was formed so that the film thickness after platinum dispersion-supported tungsten trioxide (Pt—WO) was about 1 μm after catalyst sintering.

Three

Further, the common electrode 1 in Example 2 was formed by the same method as described in the experiment of Example 1 described above. That is, the common electrode 1 was formed of gold (Au) in the shape shown in FIG. 2 (c), with a width of 0.3 mm, and only one in the longitudinal direction at the center of the detection surface. In addition, as shown in FIG. 2 (c), lands 81 and 81 for the common electrode 1 having a width of 2 mm were formed on both sides of the detection surface. After film formation, the resistance value between the electrodes 2 and 3 was about 75Ω. The junction resistances of common electrode 1 and electrode 2 and common electrode 1 and electrode 3 were about 80 kΩ, respectively. The bias power supply is connected to the common electrode 1 with a DC voltage of 5V and a current limiting resistor of 10KΩ. The bias current from electrode 2 and electrode 3 was about 60 A. The through-holes 23 have a diameter of 0.1 mm, and are formed in the exposed detection film 5 at intervals of 0.5 mm. As shown in FIG. 11, the through holes 23 are formed in four rows arranged along the longitudinal direction of the detection surface.

A circular nozzle 11 with a gas outlet (Fig. 10) with a diameter of lmm was used at the location where the gas to be detected including hydrogen gas was generated, and the jet direction was upward. The hydrogen gas detection sensor was installed so that the detection surface was placed at a distance of lmm above the gas outlet.

FIG. 12 is a graph for explaining the effect of the through hole 23 in the hydrogen gas detection sensor of Example 2 shown in FIG. 6 and FIG. In the graph of Fig. 12, the horizontal axis is the hydrogen gas detection position X [mm], and the vertical axis is the calculation result E2. In FIG. 12, a solid line 38 indicates a case where the through hole 23 is not provided, and a broken line 37 indicates a case where the through hole 23 is provided. The hydrogen gas detection position X on the horizontal axis is the value indicated as the detection position X in FIG. In this experiment, the detection position X was changed from 5mm to 95mm. In this experiment, the volume concentration of hydrogen gas is 1%.

As shown in Fig. 12, when the through hole 23 is not present (solid line 38), as shown in Fig. 12, when the hydrogen gas detection position X approaches 10 mm from the boundary (both ends) of the detection surface, the calculation result E2 The rate of change of is less. On the other hand, when there is a through-hole 23 (broken line 37), the rate of change of the calculation result E2 was almost constant even when the hydrogen gas detection position X was close to about 5mm from the boundary (both ends) of the detection surface. . FIG. 13 is a graph showing the hydrogen gas volume concentration [%] on the horizontal axis and the calculation result E1 shown in the above equation (1) on the vertical axis. In FIG. 13, a solid line 42 indicates a case where there is no through hole 23, and a broken line 41 indicates a case where the through hole 23 is present. As shown in Fig. 13, when the through hole 23 is not present (solid line 42), the calculated result E1 is larger for the volume concentration of hydrogen gas than when the through hole 23 is present (dashed line 41). Yes. This seems to be because when the through-hole 23 is present, the hydrogen gas detection range has become smaller even if the concentration of the hydrogen gas to be ejected is the same. Further, in any case where there is the through hole 23 and no through hole 23, the calculation result E1 increases as the concentration of the hydrogen gas to be ejected increases.

As is clear from the experimental results shown in FIGS. 12 and 13, by forming the through hole 23 to discharge the hydrogen gas 26, the change rate of the calculation result E2 is reduced at the boundary portion of the detection surface. It becomes possible to prevent.

Example 3

Hereinafter, a hydrogen gas detection sensor of Example 3 according to the present invention will be described with reference to FIGS. 14 to 16.

FIG. 14 is a cross-sectional view showing the configuration of the hydrogen gas detection sensor of Example 3. FIG. 15 and FIG. 16 are graphs showing experimental results in the configuration of Example 3. FIG. In the description of the third embodiment, components having the same functions and configurations as those of the first embodiment and the second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

As shown in the sectional view of FIG. 14, the hydrogen gas detection sensor of Example 3 has a structure in which a heater 39 is attached as a heating means to the hydrogen gas detection sensor of Example 1 described above and covered with a heat insulating material 32. The hydrogen gas detection sensor of Example 3 can maintain the temperature of the detection film at a predetermined temperature by providing a heating means, which improves the response speed to hydrogen gas and affects the humidity of the gas to be detected. Can be eliminated.

First, the structure of the hydrogen gas detection sensor according to the third embodiment in which the hydrogen gas detection region is one-dimensional will be described with reference to FIG.

The basic structure of the detection part of the hydrogen gas detection sensor of Example 3 is the same as that of the hydrogen gas detection sensor of Example 1 shown in FIG. In the hydrogen gas detection sensor of Example 3, the heat insulating material 32 having hydrogen gas permeability is provided around the hydrogen gas detection sensor of Example 1. Further, the heater 39 is attached to the back surface of the substrate 6. The heat insulating material 32 that is permeable to hydrogen gas is highly heat-resistant and is formed of a foaming resin such as foamed polyethylene. The heat insulating material 32 has a thickness of about 1 mm from the viewpoint of heat insulation, and has a number of holes of about 0.2 mm from the viewpoint of ensuring hydrogen gas permeability. Therefore, the gas to be detected generated outside the heat insulating material 32 passes through the hole and instantaneously reaches the internal hydrogen gas detection sensor. Example 3 The heater 39 that can be heated was formed by printing a platinum or tungsten paste and then sintering it.

Note that the hydrogen gas detection sensor of Example 3 is shown in FIG. 10, in addition to the configuration in which the heater 39 and the heat insulating material 32 are provided in the hydrogen gas detection sensor of Example 1 shown in FIG. A configuration in which the heater 39 and the heat insulating material 32 are provided in the hydrogen gas detection sensor of the second embodiment having the through hole 23 may be used. The temperature adjustment in the hydrogen gas detection sensor of Example 3 was performed by measuring the temperature using the current and voltage values of the heater 39 in advance and the thermocouple attached to the detection film 5 and preparing a calibration curve. It was.

[0089] [Experimental result of hydrogen gas sensor]

Experimental results of the hydrogen gas detection sensor according to Example 3 of the present invention will be described with reference to FIGS. FIG. 15 is a graph showing the experimental results regarding the change in the surface temperature of the detection film 5 and the response time. In FIG. 15, the horizontal axis represents the surface temperature [° C] of the sensing film 5, and the vertical axis represents the response time [second]. FIG. 16 is a graph showing the surface temperature of the detection film 5 and the calculation result E 1 shown in the above equation (1).

[0090] The hydrogen gas detection sensor used in this experiment had a one-dimensional hydrogen gas detection region, a detection length L as a detection range of 100 mm, and a width of 3 mm. As the substrate 6, quartz (SiO 2) having a length of 104 mm, a width of 3 mm, and a thickness of 1 mm was used. Electrode 2

2

The electrode 3 was formed by depositing gold (Au) with a thickness of 0.5 m on 2 mm on both sides of the substrate 6 by sputtering. The resistance layer 4 was formed by tantalum nitride (TaN) by a reactive sputtering method at a central portion with a thickness of 102 μm and a thickness of 10 μm except for a region having a width of 1 mm from both edges of the substrate 6. The resistance value of the electrode 2 and electrode 3 interelectrode resistance measured after the film formation was about 75Ω. The junction resistances between the common electrode 1 and the electrode 2 and between the common electrode 1 and the electrode 3 were about 80 kΩ, respectively. [0091] The detection film 5 was formed such that the film thickness after platinum dispersion-supported tungsten trioxide was about 1 μm after catalyst sintering. The common electrode 1 was formed by the same method as described in the experiment of Example 1 described above. That is, as for the common electrode 1, only one gold (Au) was formed in the shape shown in FIG. 2 (c) with a width of 0.3 mm along the longitudinal direction at the center of the detection surface. Also, as shown in FIG. 2 (c), lands 81, 81 for the common electrode 1 having a width of 2 mm were formed on both sides of the detection surface of the detection film 5. After film formation, the resistance value between the electrodes 2 and 3 was about 75Ω. The sensing film 5 used in this experiment has a structure having a through hole 23 as shown in FIG. The through-hole 23 has a diameter of 0.1 mm, and four rows arranged along the longitudinal direction at intervals of 0.5 mm are formed in portions other than the common electrode 1, that is, the exposed portion of the detection film 5. .

[0092] After each layer of the hydrogen gas detection sensor is formed as described above, the current limiting resistor 29 is set to 10K.

The bias current was measured with an ammeter with Ω and a noise source 27 of DC 5V. The noise current was about 50 μΑ for both the bias current between common electrode 1 and electrode 2 and the bias current between common electrode 1 and electrode 3.

In this experiment, the gas outlet from which the gas to be detected, including hydrogen gas, was placed upward, and a circular nozzle with a diameter of lmm was used. The hydrogen gas detection sensor was placed 3 mm above the gas outlet so that the detection surface of the detection film 5 faced downward.

FIG. 15 is a graph showing the relationship between the surface temperature of the detection film 5 and the response time showing the results of this experiment. In this experiment, the surface temperature of the detection film 5 was heated by the heater 39 and measured every 10 ° C from 20 ° C to 150 ° C. The response time is the time from when the gas to be detected including hydrogen gas is ejected from the gas outlet until the value of the calculation result E1 reaches 90% of the final stable value. Response time is assumed. In FIG. 16, the horizontal axis is the surface temperature [° C.] of the detection film 5, and the vertical axis is a graph showing the calculation result E1 shown in the above equation (1). 15 and 16, the solid line 69 indicates the case where the relative humidity of the detected gas is 80% RH, and the broken line 68 indicates the case where the relative humidity of the detected gas is 20% RH.

As shown in FIG. 15, as a result of this experiment, the response time becomes logarithmically faster as the surface temperature of the detection film 5 increases. Response when the surface temperature of the sensing film 5 is 60 ° C The time was about 10 seconds, and when the surface temperature of the detection film 5 was about 80 ° C or higher, it was about 5 seconds and was almost constant.

[0094] As shown in FIG. 16, when the surface temperature of the detection film 5 is 60 ° C or less, the output of the calculation result E 1 is the output when the relative humidity of the detected gas is 20% RH and 80% RH. to differ greatly. On the other hand, when the surface temperature of the detection film 5 exceeds 60 ° C, it is almost the same when the relative humidity of the gas to be detected is 20% RH and 80% RH. That is, from the experimental results shown in Fig. 15 and Fig. 16, when the surface temperature of the detection film 5 is 60 ° C or higher, the humidity dependence due to the detected gas is almost not seen, and the response time is 10 seconds or less It becomes. Furthermore, when the surface temperature of the detection film 5 exceeds 80 ° C, the response time becomes 5 seconds or less.

In addition, the inventors set the temperature of the detection film 5 to about 200 ° C, 300 ° C, and 400 ° C, and the hydrocarbon system containing hydrogen atoms such as methane (CH 2), ethane (CH 2), and propane (CH 2). Combustible

4 2 6 3 8

It was confirmed that gas could be detected. In particular, when the temperature of the detection film 5 was 300 ° C or higher, hydrocarbon combustible gas containing hydrogen atoms could be detected reliably. Example 4

Hereinafter, a hydrogen gas detection sensor and a gas detection device according to Embodiment 4 of the present invention will be described with reference to FIGS. In the description of the hydrogen gas detection sensor and the gas detection device of the fourth embodiment, the same reference numerals are given to the components having the same configurations and functions as those of the above-described embodiments, and the description thereof is omitted.

[0096] In the hydrogen gas detection sensor of Example 4, the hydrogen gas detection region is two-dimensional, and the gas detection portion of the detection film is planar. In the hydrogen gas detection sensor of Example 4, the direction of current division is a two-dimensional direction, which is an electrode force electrode for detecting current.

First, the structure of the hydrogen gas detection sensor of Example 4 will be described with reference to FIG. FIG. 17 is an exploded perspective view showing a schematic configuration of the hydrogen gas detection sensor according to the fourth embodiment of the present invention, and shows an example in which hydrogen gas 26 is detected at a position indicated by an arrow B.

[0097] A hydrogen gas detection sensor 40 having a two-dimensional hydrogen gas detection region is a thick film of tantalum nitride (TaN) formed on a substantially rectangular electrically insulating quartz (SiO 2) base material 6. Consist of

2

A substantially rectangular resistance layer 4 is formed. An electrode 47, an electrode 48, an electrode 49, and an electrode 50 made of gold (Au) are provided at the four ends of the substantially rectangular resistance layer 4. electrode 47, the electrode 48, the electrode 49, and the electrode 50 are connected to a lead wire 24 made of copper (Cu), and are connected to a computing unit 28 shown in FIG. In addition, on the resistance layer 4, when hydrogen gas is detected, the state changes to an insulating state force semiconductor state, and the electric resistance value decreases, and is substantially formed of platinum dispersion supported tungsten trioxide (Pt-W03). A rectangular detection film 5 is formed so as to cover the electrode 47, the electrode 48, the electrode 49, the electrode 50, and the resistance layer 4. A common electrode 1 made of gold (Au) is provided on the detection film 5. The common electrode 1 is connected to a lead wire 24 formed of copper (Cu), and is connected to a bias power source 27 through a current limiting resistor 29.

[0098] The hydrogen gas detection sensor 40 of Example 4 detects a position where the detection surface and the hydrogen gas are in contact with each other on the detection surface of the detection film 5 surrounded by the electrode 47, the electrode 48, the electrode 49, and the electrode 50. Is. On the sensing membrane 5, the area surrounded by the four electrodes 47, 48, 49 and 50 is the two-dimensional hydrogen gas sensing area. In this two-dimensional hydrogen gas detection area, the opposing direction of electrode 47 and electrode 48 is the X direction, and the length of the detection range in the X direction is Lx (see Fig. 17). In the two-dimensional hydrogen gas detection region, the opposing direction of the electrode 49 and the electrode 50 is the Y direction, and the length of the detection range in the Y direction is Ly (see FIG. 17).

As shown in FIG. 17, the common electrode 1 is formed so as to cover the detection range of the detection film 5. However, the common electrode 1 is configured such that the detection film 5 can be exposed to the gas to be detected. FIG. 18 is a plan view showing the shape of the common electrode 1, where (a) shows the common electrode 1 having a lattice-like mesh, and (b) shows the common electrode 1 having a plurality of circular gaps 99. ing.

The common electrode 1 in Example 4 is formed in the upper part of the detection range surrounded by the electrode 47, the electrode 48, the electrode 49, and the electrode 50, and the gas to be detected with respect to the detection film 5 in the detection range. Is a shape that can be exposed. Further, in the common electrode 1, it is desirable that the configuration in which the detection film 5 can be exposed to the gas to be detected is distributed almost uniformly throughout the entire detection range.

[0100] In FIG. 18, the detection film 5 is made of the gas to be detected by the common electrode 1 having the lattice-like mesh shown in (a) or by the common electrode 1 having the circular gap 99 shown in (b). The structure that can be exposed by hydrogen gas is shown, but the gaps with shapes other than those shown in Figure 18 are common. Of course, it is possible to provide the electrode 1 so that the detection film 5 can be exposed to hydrogen gas as the gas to be detected.

The common electrode 1 shown in FIG. 18 (a) is formed in a grid-like mesh so that lands 81 formed around the common electrode 1 are electrically connected. Accordingly, the void 99 other than the mesh is a portion where the detection film 5 can be exposed to the gas to be detected. Further, the shape of the mesh of the common electrode 1 is almost the same within the detection range. Furthermore, it is desirable that the mesh interval in the detection direction of the common electrode 1 (up / down / left / right direction in FIG. 18) is sufficiently shorter than the length of the detection direction when the hydrogen gas in the detection gas contacts the detection film 5. More preferably, the distance between the meshes in the detection direction of the common electrode 1 is sufficiently shorter than the length from the hydrogen gas ejection point to the detection film 5.

[0101] The common electrode 1 shown in FIG. 18 (b) is electrically connected to the lands 81 formed around the common electrode 1, and a large number of the detection film 5 can be exposed to the gas to be detected. A hole which is a circular gap 99 is formed. Therefore, the land 81 is electrically connected by a portion other than the hole of the common electrode 1. In addition, the hole portion which is the void 99 is a portion where the detection film 5 can be exposed to the gas to be detected. The shape of the hole is almost the same in the detection range, and the formation interval in the detection direction of the hole (the vertical and horizontal directions in FIG. 18) is almost the same length in the detection range. It is desirable that the hole formation interval be sufficiently shorter than the length in the detection direction in which the hydrogen gas in the detection gas contacts the detection film 5. More preferably, it is preferably sufficiently shorter than the length to the hydrogen gas ejection point force detection film 5.

As a means by which the detection film 5 can be exposed to the gas to be detected, the common electrode 1 has a permeability to hydrogen gas in addition to the shape of the common electrode 1 shown in FIGS. 18 (a) and (b). It is also possible to use metal materials with a thickness of 1 μm or less, such as gold (Au), silver (Ag), and copper (Cu), or porous conductors such as sintered materials. It is.

Next, a hydrogen gas detection sensor having a layered structure different from the structure of the hydrogen gas detection sensor 40 shown in FIG. 17 and having a two-dimensional hydrogen gas detection region will be described with reference to FIGS. 19 and 20. . 19 and 20 are cross-sectional views showing the laminated structure of the respective hydrogen gas detection sensors. 19 and 20, (a) is a cross-sectional view taken along a line parallel to the X direction (see Fig. 17) of the hydrogen gas detection sensor in the two-dimensional hydrogen gas detection region, and (b) is Y It is sectional drawing by a line parallel to a direction (refer FIG. 17).

In the hydrogen gas detection sensor shown in FIG. 19, a common electrode 1 is formed on a substantially rectangular base material 6, and a substantially rectangular detection film 5 and a substantially rectangular resistance layer 4 are sequentially laminated. The electrode 47, the electrode 48, the electrode 49, and the electrode 50 are formed around the four sides of the resistance layer 4 having the above structure. It is desirable that the resistance layer 4 has the same shape as the common electrode 1 shown in FIG. 18 (a) or (b), so that the detection film 5 can be reliably exposed to the gas to be detected. It becomes composition. When the resistance layer 4 does not have the shape of the common electrode 1 shown in FIG. 18 (a) or (b), the tantalum nitride (TaN) formed at a low density so as to have hydrogen gas permeability. It is also possible to use thin films such as metal oxides (CrO) and sintered porous materials such as metal oxides.

2

Is possible. The detection range of the hydrogen gas detection sensor shown in FIG. 19 is between the electrode 47 and the electrode 48 and between the electrode 49 and the electrode 50 indicated by the length LX in the X direction and the length Ly in the Y direction. .

[0104] The hydrogen gas detection sensor shown in FIG. 20 has a configuration in which a base material is not provided as a special member. The hydrogen gas sensor in Fig. 20 is sufficiently stable even at about 500 ° C, which is the sintering temperature of the sensing film 5 with high conductivity such as copper (Cu), stainless steel (SUS), and aluminum (A1). The common electrode 1 formed of a substantially strip-shaped metal foil in a state is used as a base material. On the common electrode 1, a substantially rectangular detection film 5 and a substantially rectangular resistance layer 4 are sequentially laminated. An electrode 47, an electrode 48, an electrode 49, and an electrode 50 are formed around the four sides of the resistance layer 4. In this case, it is desirable that the resistance layer 4 has the same shape as that of the common electrode 1 shown in FIG. 18 (a) or (b). As a result, the detection film 5 is surely exposed to the gas to be detected. It can be configured. Further, when the resistance layer 4 does not have the shape of the common electrode 1 shown in FIG. 18 (a) or (b), the tantalum nitride (TaN) formed so as to have hydrogen gas permeability. ) And chromium oxide (CrO) thin films, metal oxides and other porous materials sintered

2

It is also possible. Furthermore, by using a metal foil with a bendable characteristic of 0.05 mm to 2 mm in thickness for the common electrode 1, a hydrogen gas detection sensor having a flexible shape characteristic that can be bent can be realized. It becomes possible.

[0105] Next, the resistance value between electrode 47 and electrode 48 (hereinafter referred to as interelectrode resistance), the resistance value between electrode 49 and electrode 50 (hereinafter referred to as interelectrode resistance), and detection film 5 detects hydrogen gas. In a state where it is not in contact The relationship of the resistance values (hereinafter referred to as junction resistance) with the electrodes 47, 48, 49 and 50 with respect to the common electrode 1 will be described.

When the bias power supply 27 is connected to the common electrode 1, the detection film 5 detects hydrogen gas, and in this state, the common electrode 1 and the electrode 47, the common electrode 1 and the electrode 48, the common electrode 1 and the electrode 49, and the common electrode A current that is inversely proportional to the combined resistance of the current limiting resistance and the junction resistance (hereinafter referred to as a bias current) flows between 1 and the electrode 50.

When the detection film 5 detects (contacts) hydrogen gas, a part of the detection film 5 is converted into a semiconductor, and common electrode 1 and electrode 47, common electrode 1 and electrode 48, common electrode 1 and electrode 49, and common electrode 1 and electrode Current flowing between 50 and 50 increases. Based on this increased current value, it is possible to detect the position where the detection film 5 becomes a semiconductor and the concentration of hydrogen gas. Therefore, the bias current is larger than the amount of current that increases when the detection film 5 detects hydrogen gas, and the sensitivity and resolution, so-called SZN ratio, are affected by changes in the bias current. Therefore, it is desirable to set the junction resistance to a value higher than the interelectrode resistance. The value of the junction resistance is preferably about 1 times or more, preferably 10 times or more, more preferably 100 times or more with respect to the value of the resistance between electrodes.

[0106] In the hydrogen gas detection sensor having a two-dimensional hydrogen gas detection region, when the detection range is widened, the inter-electrode resistance increases while the junction resistance decreases. Therefore, it is desirable to adjust the shape and film thickness of the common electrode 1, the resistance layer 4 and the sensing film 5 described below to improve the ratio of the junction resistance to the resistance between the electrodes.

Junction resistance is increased by reducing the area where the common electrode 1 and the sensing film 5 are joined, reducing the area where the resistive layer 4 and the sensing film 5 are joined, or increasing the film thickness of the sensing film 5. Can be made. The interelectrode resistance can be reduced by increasing the thickness of the resistance layer 4.

[0107] [Material for hydrogen gas detection sensor]

Next, the base material and specific materials of each layer in the hydrogen gas detection sensor 40 of Example 4 having a two-dimensional hydrogen gas detection region will be described.

The substrate 6 is an electrically insulating material, and can be used as long as it is in a stable state at a heating temperature of 500 ° C. when the detection film 5 is sintered. The base material 6 of Example 4 is quartz (SiO 2). However, in addition to quartz (SiO 2), silicon (SiO 2) and nitride with surface insulation treatment were used.

2 Aluminum dioxide (A1N), alumina (A120), etc. can be used. In addition, rosin-based

Three

As the material, for example, a heat-resistant phenolic material such as Timold made by Nikko Kasei Co., Ltd. can be used. In this case, it is possible to obtain a three-dimensional shape other than a flat surface by using an injection molding method. Furthermore, as the flexible sheet-like material, for example, a polyimide-based material such as Kapton (registered trademark) manufactured by Toray DuPont can be used. Polyimide-based materials can be used by performing a sintering temperature of the force detection film 5 having a maximum heat resistance of about 450 ° C at about 450 ° C.

[0108] As the resistance layer 4, a thin film resistor formed by vapor deposition or the like, a thick film resistor formed by sintering after printing, or the like can be used. In particular, a thin film resistor formed by vapor deposition or the like is desirable because it is easy to form the detection film 5 having a uniform film thickness on the resistance layer 4 where the surface roughness of the resistance layer is small. Thin film resistor materials include single metal such as tantalum (Ta), nickel chrome (NiCr), nickel chrome 'silicon alloy (NiCr—Si), tantalum' silicon alloy (Ta—Si), niobium 'silicon alloy. Alloy thin films such as (Nb—Si), cermet thin films such as chrome 'acid silicon (Cr-SiO 2), tantalum' silicon oxide (Ta—SiO 2), ruthenium oxide

twenty two

2 2 3

Further, the electrode 47, the electrode 48, the electrode 49, and the electrode 50 are materials having high conductivity, and can be used as long as they are stable at about 500 ° C. that is the sintering temperature of the detection film 5. It is more desirable that the electrode itself is inert to the combustible gas containing hydrogen atoms in the gas to be detected. The material of electrodes 47, 48, 49 and 50 is magnesium, which is a highly conductive material.

(Mg), aluminum (A1), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), nickel (Ni), silver (Ag) and other metals, carbon (C) Etc. can be used. In particular, the material of the electrodes 47, 48, 49 and 50 is preferably gold (Au) or copper (Cu), which is inert to hydrogen gas that is difficult to oxidize.

[0109] As the detection film 5, any substance can be used as long as it has a property of changing resistance in electrical characteristics when it comes into contact with hydrogen gas. For example, tin oxide (SnO),

2 Molybdenum trioxide (MnO), tungsten trioxide (WO), titanium dioxide (TiO), water

2 3 2 Iridium oxide (Ir (OH) n), Vanadium pentoxide (VO), Rhodium oxide (Rh O · χΗ o) etc. can be used.

In the common electrode 1, the electrode is a highly conductive material, and it is more desirable that the electrode itself is inert to the hydrogen gas in the gas to be detected. Common electrode 1 materials are magnesium (Mg), aluminum (A1), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), nickel (Ni), which are highly conductive materials. Metal such as silver (Ag), carbon (C), etc. can be used. In particular, the material for the common electrode 1 is preferably gold (Au) or copper (Cu), which is inert to hydrogen gas that is difficult to oxidize.

[0110] [Operation principle of hydrogen gas detection sensor]

Next, the operation principle of hydrogen gas detection of the hydrogen gas detection sensor 40 of Example 4 will be described.

In FIG. 17, the case where the hydrogen gas 26 contained in the gas to be detected contacts the detection film 5 formed of platinum dispersion-supported tungsten trioxide at the position indicated by the arrow B will be described. This platinum-dispersed supported trioxide-tungsten trioxide is a platinum (hereinafter referred to as Pt) fine particle having a lnm force of about lOnm as a catalyst. It has a dispersed support structure. The hydrogen gas is dissociated platinum (Pt) Proton on microparticles (H +) and electron (e ^_). The dissociated protons (H +) spill over from the platinum catalyst fine particles, and diffuse into tritandane trioxide (WO), which is the main component of the detection film 5, to form tungsten bronze. Tungsten trioxide (WO)

3 3 is a state in which tungsten bronze is formed and is in a state that is close to electrical insulation. However, tungsten trioxide (WO) diffuses protons (H +)

Three

When the bronze is formed, it becomes a semiconductor, and the detection film 8 of the detection film 5 becomes close to a conductor.

On the other hand, the current generated from the noise power source 27 connected to the common electrode 1 intensively flows through the semiconductor-made detection unit 8. The current flowing through the detection unit 8 flows from the detection unit 8 through the resistance layer 4 to each of the electrodes 47, 48, 49, and 50 while being divided. The current flowing through the resistance layer 4 can be roughly divided into an X-direction current flowing through the electrodes 47 and 48 and a Y-direction current flowing through the electrodes 49 and 50. The current flowing in the X direction is the distance Xa from the electrode 47 to the semiconducting sensing position, and from the electrode 48 to the semiconducting sensing position. The current is divided in inverse proportion to the ratio of the distance Xb, and is output as a current signal from the electrodes 47 and 48. On the other hand, the current flowing in the Y direction is current-divided in inverse proportion to the ratio of the distance Ya from the electrode 49 to the detection position made semiconductor and the distance Yb from the electrode 50 to the detection position made semiconductor, 49 and electrode 50 output as current signals.

Next, FIG. 21 shows the operation of the computing unit 28 which is a conversion means for converting the current signal output from each electrode 47, 48, 49, 50 of the hydrogen gas detection sensor 40 of Example 4 into a voltage signal. It explains using. FIG. 21 is a block diagram illustrating a configuration of the computing unit 28 to which a signal from the hydrogen gas detection sensor 40 according to the fourth embodiment is input.

As described above, in the hydrogen gas detection sensor 40 of Example 4, the exposed portion of the detection film 5 that has detected hydrogen gas is the detection unit 8 that is made into a semiconductor. In order to detect the position of the detection unit 8 on the detection film 5, the resistance change of the detection unit 8 is converted into a current value using the resistance layer 4 and input to the calculation unit 28. In the arithmetic unit 28, the current value is converted into a voltage value, and the arithmetic processing is performed. The operation of the arithmetic unit 28 as the conversion means will be described below.

As shown in FIG. 21, in the hydrogen gas detection sensor 40 of Example 4 having a two-dimensional hydrogen gas detection region, the common electrode 1 is connected to the bias power source 27 via the current limiting resistor 29. When the detection film 5 is not in contact with hydrogen gas, the current flowing between the common electrode 1 and the electrode 47 is bias current Iab, and the current flowing between the common electrode 1 and electrode 48 is the bias current Ibb, The current flowing between the common electrode 1 and the electrode 49 is defined as a bias current Icb, and the current flowing between the common electrode 1 and the electrode 50 is defined as a bias current Idb. These bias currents la b, Ibb, Icb, and Idbi, and each electrode 47, 48, 49, and 50 power are input to the calculator 28, and are composed of operational amplifiers 14a, 14b, 14c, and operational amplifier 14d. It is converted into a voltage signal by the circuit 14. The converted voltage signals are sent to analog / digital conversion elements 15a, 15b, 15c and 15d, which are converted into digital signals. Further, each converted digital signal is sent to dividers 16a and 16b and adder 17. Dividers 16a and 16b and adder 17 hold each digital signal in a state where no hydrogen gas is detected as values corresponding to bias currents lab, Ibb, Icb and Idb.

[0114] Next, in a state where the detection film 5 of the hydrogen gas detection sensor 40 of Example 4 detected hydrogen gas. The case will be described.

When the detection film 5 detects hydrogen gas, the current flowing between the common electrode 1 and the electrode 47 is Ia, the current flowing between the common electrode 1 and the electrode 48 is Ib, and the current between the common electrode 1 and the electrode 49 is The current flowing between them is Ic, and the current flowing between the common electrode 1 and the electrode 50 is Id.

Similar to the bias currents lab, Ibb, Icb and Idb described above, the currents Ia, Ib, Ic and Id are input to the calculator 28 from the electrodes 47, 48, 49 and 50, respectively. It is converted into a voltage signal in the circuit. The converted voltage signals are sent to analog / digital conversion elements 15a, 15b, 15c and 15d, respectively, which are converted into digital signals and sent to dividers 16a, 16b and adder 17. In the dividers 16a, 16b and the adder 17, the digital signals corresponding to the bias currents lab, Ibb, Icb and Idb that have been held are subtracted from the digital signal forces corresponding to la, lb, Ic and Id, respectively. Then, calculation processing of addition and division shown in Expression (8) to Expression (10) described later is performed. The calculation results by addition and division are input to the digital / analog conversion elements 18a, 18b and 18c as digital electric signals. The digital / analog conversion element 18c outputs the calculation result E3 by the addition of the analog electrical signal. The digital / analog conversion element 18a outputs the calculation result E4X by division in the X direction, and the digital / analog conversion element 18b outputs the calculation result E4Y by division in the Y direction. Calculation result in X direction E4X is the calculation result indicating the detection position of hydrogen gas in the X direction on the detection film 5, and division result E4Y is the calculation result indicating the detection position of hydrogen gas in the Y direction on the detection film 5 It is a result.

[0115] The above calculation results E3, E4X, E4Y are calculated by the following equations (8), (9), and (10).

[0116] E3 = k21 X {(la— lab) + (lb— Ibb) + (Ic— Icb)

+ (Id— Idb)} (8)

[0117] E4X = kl3 X (lb— Ibb) / {(la— lab)

+ (lb— Ibb)} (9)

[0118] E4Y = kl4 X (Id— Idb) / {(Ic— Icb)

+ (Id— Idb)} (10)

In the above formulas (8), (9), and (10), k21, kl3, and K14 are constants. [0120] In the hydrogen gas detection sensor 40 of Example 4 shown in FIG. 17, the calculation result E4X is 0 when the detection position is X = 0, and the calculation result E4X is when X = Lx. Becomes 1. Here, X = 0 is the position where the semiconductor detection unit 8 is in the vicinity of the electrode 47 in the configuration shown in FIG. 17 and the position of one boundary portion of the detection range L in the X direction. Therefore, X = L is the position where the detection unit 8 is close to the electrode 48 and the position of the other boundary portion of the detection range L in the X direction.

[0121] In addition, the calculation result E4Y is 0 when the detection position is Y = 0, and the calculation result E4Y is 1 when Y = Ly. Here, Y = 0 is the position where the detection unit 8 which is a semiconductor is close to the electrode 49 in the configuration shown in FIG. 17, and is the position of one boundary part of the detection range L in the vertical direction. . Therefore, Y = L is the position where the detection unit 8 is close to the electrode 50 and the position of the other boundary portion of the detection range L in the Y direction.

[0122] Equations (9) and (10) indicate that the hydrogen gas detection potential changes from = 0 to = 1 ^: and from Y = 0 to Y = Ly. The relationship between the positions X and Y and the calculation results E4X and E4Y is a relationship represented by a straight line when shown on the vertical and horizontal graphs.

In the hydrogen gas detection sensor 40 according to the fourth embodiment of the present invention, the calculation process is not limited to the above formulas (9) and (10), and the calculation can be performed using other formulas. be able to.

[0123] An arithmetic expression indicating the hydrogen gas detection position other than Expression (9) and Expression (10) will be described below.

The expression for the X direction contains a term representing the ratio of (la—lab) to (lb—Ibb), and the expression for the Y direction contains a term representing the ratio of (Ic—Icb) to (Id—Idb). If! /, It can be used as an arithmetic expression to indicate the hydrogen gas detection position. An example of a calculation method that shows the specific hydrogen gas detection position is described below.

[0124] In the hydrogen gas detection sensor 40 of Example 4 shown in FIG. 17, the following formula (11) is calculated when the detection position force ¾ = 0, and the calculation result EX is 0, and when X = Lx This is an arithmetic expression in which EX becomes ∞. Equation (12) is an arithmetic expression in which the calculation result EY is 0 when the detection position is Y = 0, and the calculation result ΕΥ is ∞ when Y = Ly. Equation (11) and Equation (12) In both cases, the relationship between the hydrogen gas detection position and the calculation result E cannot be expressed as a straight line when shown on the vertical and horizontal graphs.

[0125] EX = kl5X (lb— Ibb) / (la— lab) (11)

[0126] EY = kl6X (Id— Idb) Z (Ic— Icb) (12)

[0127] In addition, in the hydrogen gas detection sensor 40 of Example 4 shown in Fig. 17, the following expression (13) is obtained when the detection position force ¾ = 0 and the calculation result EX is -1 and X = Lx This is the calculation formula for the calculation result EX force. In the calculation of equation (14), the calculation result ΕΥ is −1 when the detection position is Y = 0, and the calculation result ΕΥ is 1 when the detection position is Y = Ly. In the calculations of Equations (13) and (14), when the hydrogen gas detection position force changes from X = 0 to L, the relationship between the hydrogen gas detection position and the calculation result E is indicated by the vertical and horizontal axes. It is represented by a straight line.

[0128] EX = kl7X [{(lb— Ibb)-(la— lab)} /

{(la— lab) + (lb— Ibb)}] (13)

[0129] EY = kl8X [{(Id— Idb)-(Ic— Icb)} /

{(Ic— Icb) + (Id— Idb)}] (14)

[0130] In the above formulas (8) to (14), the output currents la, Ib, Ic and Id of the hydrogen gas detection sensor 40 are sufficiently larger than the bias currents lab, Ibb, Icb and Idb. If it is a value, it is possible to calculate by ignoring the bias currents lab, Ibb, Icb and Idb. In that case, Equation (8) to Equation (14) are as shown in Equation (21) below.

[0131] E3 = k22X (Ia + Ib + Ic + Id) (15)

[0132] EX = k7XIb / (lb + Ia) (16)

[0133] EY = k8XId / (lc + Id) (17)

[0134] EX = k9XIb / la (18)

[0135] EY = klOXId / lc (19)

[0136] EX = kllX (lb-Ia) / (la + Ib) (20)

[0137] EY = kl2X (Id— Ic) / (lc + Id) (21)

As described above, the hydrogen gas of Example 4 having the two-dimensional hydrogen gas detection region shown in FIG. In the hydrogen detection sensor 40, the hydrogen gas detection position can be calculated by an arithmetic expression expressed by the equations (8) to (21).

The bias power supply 27 used in the hydrogen gas detection sensor 40 of Example 4 is described as a DC power supply. However, the DC power supply alone is not the only bias power supply in the gas detection sensor of the present invention. The AC power supply can be used. In that case, it is necessary to add a rectification function to the current-voltage converter of the arithmetic unit 28.

In addition, the arithmetic unit 28 in the fourth embodiment converts the output current from the hydrogen gas detection sensor 40 into a digital signal and performs an operation, but does not convert it into a digital signal but performs an operation according to a circuit configuration in an analog signal state. It is also possible to do.

[0139] [Experimental result of hydrogen gas detection sensor]

Experimental results of the hydrogen gas detection sensor 40 and the gas detection device of Example 4 according to the present invention will be described with reference to FIGS. 22 and 23. FIG.

First, the hydrogen gas detection sensor with a two-dimensional hydrogen gas detection region used in this experiment will be described.

In the hydrogen gas detection sensor 40 having a two-dimensional hydrogen gas detection region used in this experiment, the length Lx in the X direction and the length Ly in the Y direction of the detection range were each 100 mm. As the base material 6, quartz (Si 02) having a length in the X direction of 104 mm, a length in the Y direction of 104 mm, and a thickness of 1 mm was used. The electrode 47, the electrode 48, the electrode 49, and the electrode 50 were formed using gold (Au), and were formed with a width of 2 mm and a thickness of 0.5 m inside the edge portions of the four sides of the substrate 6. The resistance layer 4 was formed by forming tantalum nitride (TaN) with a thickness of 3 μm in the central portion 102 mm except for the inner side lmm of the four sides of the base material 6.

[0140] The sensing film 5 was formed so that the film thickness after platinum dispersion-supported tungsten trioxide was about 1 μm after catalyst sintering. A sol-gel method was used as a forming method. Specifically, first, sodium tungstateate dihydrate (Na WO 2Η O: manufactured by Junsei Chemical Co., Ltd.) 41.2 g

2 4 2

The sample was placed in a volumetric flask and adjusted to 250 mL with pure water, to obtain a 0.5 molZL colorless and transparent aqueous sodium tandateate (Na 2 WO 3) solution.

twenty four

[0141] Next, cation exchange resin (Amberlite IR120B Na: manufactured by Organo Corporation) was filled into a column tower, and a sodium tungstate (Na 2 WO) aqueous solution was passed through the column tower. The sodium ion (Na +) in the sodium acid (Na WO) aqueous solution is exchanged for protons (H +)

twenty four

2 4 2 4

mL of catalyst metal hexachloroplatinic acid (H PtCl 6Η Η: Wako Pure Chemical Industries, Ltd.

2 6 2

4 mL of an aqueous solution in which 0.5 molZL was dissolved in pure water and 8 mL of ethanol were uniformly dispersed and mixed to synthesize a sol-gel solution of platinum-dispersed tungsten oxide. The sol-gel solution was uniformly dropped on the resistance layer 4 so as to cover the entire surface, and the sol-gel solution was applied by a dipping method. Then, after drying at room temperature for 1 hour, using an electric furnace, pre-baked at 200 ° C. for 1 hour, and further fired at 500 ° C. for 1 hour and then cooled at room temperature. At this time, the thickness of the detection film 5 was 1 μm.

[0142] Next, the common electrode 1 made of gold (Au) was formed using a sputtering method and a metal mask. As shown in FIG. 18 (a), the common electrode 1 is 0.1 mm wide and 2.5 mm apart so that it has a lattice-like mesh as shown in FIG. 39 in each direction. A land 81 having a width of 2 mm was provided around the common electrode 1. The thickness of the common electrode 1 was controlled by controlling the sputtering time and sputtering power, and was 2 m in this experiment.

After the formation of common electrode 1, the junction resistances of common electrode 1 and electrode 47, common electrode 1 and electrode 48, common electrode 1 and electrode 49, and common electrode 1 and electrode 50 were measured. The junction resistance was 5 OkΩ each. The resistance values of the interelectrode resistances of the electrode 47 and the electrode 48 and the electrode 49 and the electrode 50 were about 50Ω.

[0143] The evaluation was performed under the following conditions. In the hydrogen gas detection sensor 40 of Example 4 configured as described above, the hydrogen gas detection region is two-dimensional, and a DC voltage of 5 V was applied to the common electrode 1 from the noise power source 27. The current limiting resistance is 5ΚΩ. The bias current from electrode 47, electrode 48, electrode 49, and electrode 50 was about 100 A. A circular nozzle with a gas outlet diameter of lmm was used at the location where the detected gas containing hydrogen gas was ejected, and the ejection direction was upward. The experiment was conducted with the hydrogen gas detection sensor 40 installed at a distance of 1 mm and 3 mm above the gas outlet.

[0144] Fig. 22 shows the hydrogen gas when the distance to the detection film 5 of the gas jetting hydrogen hydrogen detection sensor 40 is lmm and the volume concentration of hydrogen gas of the detected gas is 0.1% and 1%. It is a graph which shows the relationship between a detection position and a calculation result (E4X, E4Y). (A) in Fig. 22 is X 5 is a graph showing the relationship between the hydrogen gas detection position X, which is the nozzle position in the direction, and the calculation result E4X, and (b) is a graph showing the relationship between the hydrogen gas detection position Y in the Y direction and the calculation result E4Y. The constants kl3 and kl4 in the above formulas (9) and (10) are calculated as 1. In the graph of FIG. 22, a solid line 33 indicates a case where the volume concentration of hydrogen gas is 0.1%, and a broken line 34 indicates a case where the volume concentration of hydrogen gas is 1.0%. In addition, the hydrogen gas detection positions X and Y on the horizontal axis are the values of the detection positions X and Y shown in FIG. 17 and were measured from 20 mm to 80 mm.

As shown in the graphs (a) and (b) of Fig. 22, the calculation results E4X and E4Y show the hydrogen gas detection position regardless of the volume concentration of the hydrogen gas to be detected. It has been confirmed that it functions well as a hydrogen gas detection sensor 40 whose knowledge area is two-dimensional.

[0145] In the graph shown in Fig. 23, the hydrogen gas detection positions X and Y are the center of the two-dimensional hydrogen gas detection area (X = 50 mm, Y = 50 mm), and 2 from the gas outlet (nozzle port). The addition result E3 is shown when the volume concentration of hydrogen gas in the gas to be detected is changed from 0% to 1% when the distance to the detection surface of the three-dimensional hydrogen gas detection region is lmm and 3mm. In Fig. 23, the solid line 35 represents the case where the distance from the gas ejection locus to the detection surface is lmm, and the broken line 36 represents the case where the distance from the gas ejection locus to the detection surface is 3 mm. The constant k21 in the above equation (8) is calculated as 1 × 10 ³ (V / A).

[0146] As shown in FIG. 23, the calculation result E3 increases as the hydrogen concentration increases, regardless of whether the distance indicated by the solid line is lmm or the distance indicated by the broken line is 3 mm. . However, there is a difference in the calculation result E3 depending on the distance to the gas ejection locus detection film 5. This is because the area of the hydrogenated gas in contact with the detection film 5 increases as the distance to the detection film 5 also increases, so the range of the detection part 8 that is semiconductor-coated increases. It can be presumed that the current passing through has increased. From these results, it is possible to measure the volume concentration of hydrogen gas in the gas to be detected by measuring the calculation result E3 by keeping the distance from the gas ejection port to the detection film 5 constant.

Example 5

[0147] Hereinafter, the hydrogen gas detection sensor of Example 5 according to the present invention will be described with reference to Figs. I will explain. In the fifth embodiment, components having the same configurations and functions as those of the respective embodiments described above are denoted by the same reference numerals, and description thereof is omitted.

FIG. 24 is a cross-sectional view showing the laminated structure of the hydrogen gas detection sensor of Example 5, and shows an example in which hydrogen gas is detected at the position indicated by arrow B. The hydrogen gas detection sensor of Example 5 is a gas detection sensor having a two-dimensional hydrogen gas detection region.

The hydrogen gas detection sensor of Example 5 has a structure in which a through hole 23 penetrating from the detection film 5 to the substrate 6 is formed in the hydrogen gas detection sensor of Example 4 described above. The through-hole 23 has a function of allowing a gas to be detected including hydrogen gas in contact with the detection film 5 to pass from the detection film 5 through the substrate 6 to the outside of the hydrogen gas detection sensor. In other words, the through-hole 23 prevents the gas to be detected from staying on the detection film 5 and diffusing.

FIG. 25 is a plan view of the hydrogen gas detection sensor of Example 5, showing the detection surface.

As shown in FIG. 25, the through hole 23 is provided in the portion of the detection film 5 exposed from the common electrode 1 having a lattice-like mesh. In Example 5, the common electrode 1 has a mesh shape as shown in FIG. 18 (a) described above, but other shapes can also be used. Further, the through hole 23 can be formed in a portion other than the detection film 5. However, when it is provided in the common electrode 1 or the land 81, it is necessary to form the through-hole 23 so that the respective portions of the common electrode 1 and the land 81 are maintained in an electrically connected state so as to perform their functions. is there.

[0149] [Experimental result of hydrogen gas detection sensor]

Experimental results of the hydrogen gas detection sensor and gas detection device of Example 5 according to the present invention will be described with reference to FIGS. 26 and 27. FIG. FIG. 26 and FIG. 27 show the effect of preventing the hydrogen gas from staying with the presence or absence of the through hole 23 in the hydrogen gas detection sensor.

The hydrogen gas detection sensor used in this experiment has a two-dimensional hydrogen gas detection area. The detection range has a length Lx in the X direction and a length Ly in the Y direction of 100 mm. As the substrate 6, quartz (Si02) having a length in the X direction of 104 mm, a length in the Y direction of 104 mm, and a thickness of 1 mm was used. The electrode 47, the electrode 48, the electrode 49, and the electrode 50 were formed with a width of 2 mm and a thickness of 0.5 m on four sides of the base material 6 by sputtering gold (Au). Resistive layer 4 is made of tantalum nitride (TaN) by the reactive sputtering method and the peripheral edge of substrate 6 Excluding the minute lmm, it was formed in the center part with a thickness of 102mm and 3m.

[0150] The detection film 5 in Example 5 was formed by the same method as described in the experiment of Example 1 described above. That is, the detection film 5 was formed so that the film thickness after platinum dispersion-supported tungsten trioxide was about 1 μm after catalyst sintering.

Further, the common electrode 1 in Example 5 was also formed by the same method as described in the experiment of Example 1 described above. That is, the common electrode 1 is made of gold (Au) in the shape shown in FIG. 18A, with a width of 0.1 mm, a spacing of 2.5 mm, and a number of 39 in the X and Y directions. did. A land 81 having a width of 2 mm was formed around the detection surface. After the film formation, the resistance values of the interelectrode resistances of the electrode 47 and the electrode 48 and the electrode 49 and the electrode 50 were about 50Ω. The junction resistance of each electrode 47, 48, 49 and 50 with respect to the common electrode 1 was about 50 kΩ. The bias power supply is connected to the common electrode 1 with a DC voltage of 5V through a current limiting resistor of 10Ω. Each bias current from electrode 47, electrode 48, electrode 49, and electrode 50 was about 100 A. The voltage of the bias power supply 27 during the experiment was also 5V. In addition, a large number of through holes 23 are formed in the exposed detection film 5 with a diameter of 0.15 mm, with an interval in the X direction and an interval in the Y direction of 0.5 mm.

[0151] A circular nozzle 11 having a gas outlet diameter of lmm was used at the location where the detected gas containing hydrogen gas was generated, and the jet direction was set upward. The hydrogen gas detection sensor was installed so that the detection surface was placed at a distance of 1 mm above the gas outlet.

FIG. 26 is a graph for explaining the effect of the through hole 23 in the hydrogen gas detection sensor of Example 5 shown in FIGS. 24 and 25. In the graph shown in Fig. 26 (a), the horizontal axis is the hydrogen gas detection position X [mm] in the X direction, and the vertical axis is the calculation result E4X in the X direction. In the graph shown in (b) of FIG. 26, the horizontal axis is the hydrogen gas detection position Y [mm] in the Y direction, and the vertical axis is the calculation result E4Y in the Y direction. In FIGS. 26 (a) and (b), the solid line 38 shows the case where there is no through hole 23, and the broken line 37 shows the case where there is a through hole 23.

[0152] The hydrogen gas detection position X, which is the 11 position of the nozzle X in the X direction in Fig. 26 (a), is the value of X in Fig. 17 used in the description of Example 4 above. Measured over the range up to. In addition, the hydrogen gas detection position Y, which is the nozzle position in the Y direction in FIG. The Y value in Fig. 17 was measured in the range from 5mm to 95mm. In this experiment, the volume concentration of hydrogen gas ejected from the gas ejection port of the nozzle 11 is set to 1%. As can be seen from the graph in FIG. 26, when there is no through hole 23 (solid line 38), the calculation result E4X when the hydrogen gas detection position approaches 1 Omm from the boundary of the detection surface in both the X and Y directions. And the rate of change of E4Y is less. On the other hand, when there was a through hole 23 (broken line 37), the rate of change of the calculation results E4X and E4Y was almost constant even when the hydrogen gas detection position approached about 10 mm from the boundary of the detection surface.

In FIG. 27, the horizontal axis is the hydrogen gas volume concentration [%], and the vertical axis is the graph showing the calculation result E3 shown in the above equation (8). In FIG. 27, a solid line 42 indicates a case where the through hole 23 is not present, and a broken line 41 indicates a case where the through hole 23 is present. As shown in Fig. 27, when there is no through hole 23 (solid line 42), the calculation result E3 is larger for the volume concentration of hydrogen gas than when there is a through hole 23 (dashed line 41). Yes. This is probably because the detection range of the hydrogen gas has become smaller when the through-hole 23 is provided, even if the concentration of the hydrogen gas to be ejected is the same. Further, in any case where there is a through hole 23 and no through hole 23, the calculation result E3 increases as the concentration of the hydrogen gas to be ejected increases. As is clear from the experimental results shown in Fig. 26 and Fig. 27, the rate of change in the calculated results E4X and E4Y at the boundary of the detection surface is obtained by forming the through hole 23 to discharge hydrogen gas. A decrease can be prevented.

Example 6

[0154] Hereinafter, a hydrogen gas detection sensor according to Example 6 of the present invention will be described with reference to FIGS.

FIG. 28 is a cross-sectional view showing the configuration of the hydrogen gas detection sensor of Example 6, and shows an example in which hydrogen gas is detected at a position indicated by an arrow A. FIG. FIG. 29 and FIG. 30 are graphs showing experimental results in the configuration of Example 6. FIG. In the description of the sixth embodiment, components having the same functions and configurations as those of the previous embodiments are denoted by the same reference numerals, and the description thereof is omitted. As shown in the sectional view of FIG. 28, the hydrogen gas detection sensor of Example 6 has a structure in which a heater 39 is attached as a heating means to the hydrogen gas detection sensor of Example 4 described above and covered with a heat insulating material 32. The hydrogen gas detection sensor of Example 6 is provided with a heating means, thereby The temperature can be maintained at a predetermined temperature, the response speed to hydrogen gas can be improved, and the influence of the humidity of the gas to be detected can be eliminated.

First, the structure of the hydrogen gas detection sensor having the two-dimensional hydrogen gas detection region of Example 6 will be described with reference to FIG.

The basic structure of the detection part of the hydrogen gas detection sensor of the sixth embodiment is the same as that of the hydrogen gas detection sensor having the two-dimensional hydrogen gas detection area of the fourth embodiment shown in FIG. The hydrogen gas detection sensor of Example 6 has a structure in which the periphery of the hydrogen gas detection sensor of Example 4 is covered with a hydrogen gas-permeable heat insulating material 32, and a heater 39 is attached to the back surface of the substrate 6. . The heat insulating material 32 that is permeable to hydrogen gas is formed of a foamable resin such as foam polyurethane having high heat resistance. The heat insulating material 32 has a thickness of about 1 mm from the viewpoint of heat insulating properties, and has a number of holes of about 0.2 mm from the viewpoint of ensuring hydrogen gas permeability. Therefore, the gas to be detected generated outside the heat insulating material 32 passes through the holes of the heat insulating material 3 and instantaneously contacts the internal hydrogen gas detection sensor. The heater 39 in Example 6 was formed by printing a platinum or tungsten paste and then sintering.

[0156] The hydrogen gas detection sensor of Example 6 includes the penetration shown in Fig. 24 in addition to the configuration in which the heater 39 and the heat insulating material 32 are provided in the hydrogen gas detection sensor of Example 4 shown in Fig. 17. A configuration in which the heater 39 and the heat insulating material 32 are provided in the hydrogen gas detection sensor of the embodiment 5 having the holes 23 may be used. Temperature adjustment in the hydrogen gas detection sensor of the embodiment 6 is based on the current and voltage values of the heater 39 in advance. Then, the temperature was measured using a thermocouple attached to the sensing film 5, and a calibration curve was prepared.

[0157] [Experimental result of hydrogen gas sensor]

Experimental results of the hydrogen gas detection sensor according to Example 6 of the present invention will be described with reference to FIGS. 29 and 30. FIG. FIG. 29 shows the experimental results of the change in the surface temperature of the detection film 5 and the response time. In FIG. 29, the horizontal axis represents the surface temperature [° C.] of the detection film 5, and the vertical axis represents the response time [second]. FIG. 30 shows the surface temperature of the detection film 5 and the calculation result E3 shown in the above equation (8). In FIG. 30, the horizontal axis represents the surface temperature [° C] of the detection film 5, and the vertical axis represents the calculation result E3. In Fig. 29 and Fig. 30, broken line 68 indicates the case where the relative humidity of the gas to be detected is 20% RH. The solid line 69 shows the case where the relative humidity of the gas to be detected is 80% RH.

[0158] The hydrogen gas detection sensor used in this experiment has a two-dimensional hydrogen gas detection area, and the detection range is a detection length Lx in the X direction and a detection length Ly in the Y direction of 1 OOmm. As the substrate 6, quartz (Si02) having a length in the X direction of 104 mm, a length in the Y direction of 104 mm, and a thickness of 1 mm was used. The electrode 47, the electrode 48, the electrode 49, and the electrode 50 were formed by sputtering gold (Au) on the four sides of the substrate 6 with a width of 2 mm and a thickness of 0.5 m. The resistance layer 4 was formed by tantalum nitride (TaN) by a reactive sputtering method at a central portion of 102 mm and a thickness of 3 m, except for a region having a width of 1 mm from the peripheral edge of the substrate 6. The detection film 5 was formed so that the thickness of the platinum dispersion-supported tungsten trioxide was about 1 μm after catalyst sintering. The common electrode 1 was provided with gold (Au) in the shape shown in FIG. 18 (a) so that the width was 0.1 mm, the interval was 2.5 mm, and the number in the X and Y directions was 39 each. A land 81 with a width of 2 mm was provided around the detection surface. Around the hydrogen gas detection sensor, a heat insulating material 32 made of foaming resin having a thickness of 1 mm was formed. The heat insulating material 32 was provided with a number of 0.2 mm holes.

[0159] Thereafter, the interelectrode resistance was measured, and the interelectrode resistance between the electrode 47 and the electrode 48 and the interelectrode resistance between the electrode 49 and the electrode 50 were about 50Ω. In addition, each junction resistance of the electrode 47, the electrode 48, the electrode 49, and the electrode 50 with respect to the common electrode 1 was about 5 OkΩ. The noise power source was connected to the common electrode 1 with a DC voltage of 5V and a current limiting resistance of 10ΚΩ. The bias current from electrode 47, electrode 48, electrode 49, and electrode 50 was about 100 A. Note that the voltage of the bias power supply 27 in this experiment was 5V.

[0160] In this experiment, the gas outlet from which the gas to be detected including hydrogen gas was ejected was placed upward, and a circular nozzle with a diameter of lmm was used. In addition, the hydrogen gas detection sensor having a two-dimensional hydrogen gas detection region was arranged at a distance of 3 mm above the gas outlet so that the detection surface of the detection film 5 faced downward.

[0161] The results of this experiment are shown in Fig. 29 and Fig. 30, and Fig. 29 is a graph showing the relationship between the surface temperature of the sensing surface 5 and the response time, and Fig. 30 is the surface temperature of the sensing film 5 and the calculated value. It is a graph showing the relationship of the result E3. In FIGS. 29 and 30, the broken line 68 indicates the case where the relative humidity of the detected gas is 20% RH, and the solid line 69 indicates the case where the relative humidity of the detected gas is 80%. . The response time is measured by measuring the time from when the gas to be detected including hydrogen gas is ejected from the gas outlet until the calculated E3 value finally reaches 90% of the stable value. It was time.

As shown in FIG. 29, as a result of this experiment, the response time becomes logarithmically faster as the surface temperature of the detection film 5 increases. When the surface temperature of the detection film 5 is 60 ° C, the response time is about 10 seconds, and when the surface temperature of the detection film 5 is about 80 ° C or more, it takes about 5 seconds and is almost constant. .

[0162] As shown in Fig. 30, when the surface temperature of the detection film 5 is 60 ° C or less, the calculation result E3 output is when the relative humidity of the detected gas is 20% RH and 80% RH. It differs greatly. On the other hand, when the surface temperature of the detection surface exceeds 60 ° C, it is almost the same when the relative humidity of the gas to be detected is 20% RH and 80% RH. That is, from the experimental results shown in FIG. 29 and FIG. 30, when the surface temperature of the detection film 5 is 60 ° C. or higher, the humidity dependence due to the detected gas is almost not seen, and the response time is 10 Less than a second. Furthermore, when the surface temperature of the sensing film 5 exceeds 80 ° C, the response time becomes 5 seconds or less.

4 2 6 3 8

It was confirmed that gas could be detected. In particular, when the temperature of the detection film 5 was 300 ° C or higher, hydrocarbon combustible gas containing hydrogen atoms could be detected reliably. Example 7

Hereinafter, a hydrogen gas detection sensor of Example 7 according to the present invention will be described with reference to FIGS. 31 to 35. FIG. In the description of the hydrogen gas detection sensor of the seventh embodiment, components having the same configuration and function as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted. The hydrogen gas detection sensor of Example 7 has a configuration in which the resistive layer is not used in the configuration of the hydrogen gas detection sensor described in Example 1 and Example 2 above, and a minute sensor cell is formed in a one-dimensional shape (linear shape). ).

The hydrogen gas detection sensor of Example 7 has a plurality of minute sensor cells, and the sensor cells are arranged in a substantially straight line (one-dimensional shape) with a predetermined interval. Hereinafter, the hydrogen gas detection sensor of Example 7 is referred to as a one-dimensional array type hydrogen gas detection sensor. Each sensor sensor The sensor has a detection film having a predetermined small area whose electrical resistance value changes when it comes into contact with hydrogen gas. The hydrogen gas detection sensor of Example 7 is a gas detection sensor that calculates a hydrogen gas detection position from a change in the resistance value of the sensor cell. This will be described below with reference to FIGS.

FIG. 31A is a plan view of the one-dimensional array type hydrogen gas detection sensor 110 of the seventh embodiment. FIG. 31 (b) is a cross-sectional view taken along the line WW in FIG. 31 (a). FIG. 31 (c) is a back view of the one-dimensional array type hydrogen gas detection sensor 110 shown in FIG. 31 (a). A one-dimensional array type hydrogen gas detection sensor 110 shown in FIG. 31 has a base material 101 made of quartz (SiO 2) that is formed in a substantially band shape and is electrically insulating.

2

A pole 102 is formed. The common electrode 102 is formed in a substantially strip shape along the longitudinal direction on the back surface of the substrate 101.

[0165] The detection film constituting the sensor cell 103 is made of platinum-dispersed supported tungsten trioxide (Pt-WO) that changes its state from an electrically insulating state to a semiconductor state or a conductor state when hydrogen gas is detected. The detection film of the sensor cell 103 penetrates the front and back of the substrate 101.

Three

Formed on the inner surface of the through-hole 106 and bonded to the common electrode 102 on the back surface of the substrate 101 and the detection electrode 104 formed around each through-hole 106 on the surface of the substrate 101. ing. The through holes 106 are arranged on a straight line along the longitudinal direction of the substrate 101. Therefore, the sensor cells 103 formed in the through holes 106 are arranged on a straight line that is a one-dimensional array.

[0166] As described above, in the one-dimensional array type hydrogen gas detection sensor 110 of Example 7, the detection electrode 104 paired with each sensor cell 103 is formed on the surface of the base 101, and each detection electrode is formed. 104 is connected to a sensing film bonded to the common electrode 102. The common electrode 102 formed on the back surface of the substrate 101 is connected to the detection films of all the sensor cells 103. A lead wire 108 is connected to each detection electrode 104, and is connected to a position detection device 115A (see FIG. 35) described later. The common electrode 102 is connected to the bias power supply 111 via the current limiting resistor 112.

A one-dimensional array type hydrogen gas sensor 110 of Example 7 shown in FIG. 31 has a through-hole 106 penetrating from the front surface to the back surface of the base material 101, so that the water in contact with the surface of the base material 101 The gas to be detected including the raw gas can be discharged to the back surface through the through hole 106. Accordingly, it is possible to prevent the range of the sensor cell 103 in contact with the ejected hydrogen gas from spreading the hydrogen gas on the surface of the base material 101 from diffusing on the surface of the base material 101.

In the configuration shown in FIG. 31, the example in which the through hole 106 is formed only in the sensor cell 103 has been described. However, the present invention is not limited to such a configuration. For example, through-holes for discharging the force to the back surface may be provided at appropriate intervals in the base material 101 other than the sensor cell 103, the common electrode 102, and the detection electrode 104, for example.

Next, the operation principle of hydrogen gas detection in the one-dimensional array type hydrogen gas detection sensor 110 according to the seventh embodiment will be described.

In FIG. 31B, the hydrogen gas 126 contained in the gas to be detected contacts the sensor cell 103 at the position indicated by the arrow C. The platinum dispersion-supported tungsten trioxide, which forms the sensor cell 103, is a platinum (Pt) fine particle with a particle size of about lnm to 10nm as a catalyst, and a tungsten trioxide (WO) particle with a particle size of about 10nm to lOOnm. To be dispersed and supported!

Three

. On the platinum (Pt) fine particles, the hydrogen gas 126 is dissociated into protons (H +) and electrons (e—). The dissociated proton (H +) spills over the platinum catalyst fine particles and diffuses into tungsten trioxide (WO), the main component of sensor cell 103, forming tungsten bronze.

Three

To do. Tungsten trioxide (WO) has not formed tungsten bronze.

Three

In this case, when the proton (H +), which is in an electrically close state, diffuses and forms tungsten bronze, it becomes a semiconductor, and when the concentration of hydrogen gas increases and many protons (H +) diffuse, It shows a property close to a conductor from a semiconductor. In general, the resistance value of the sensor cell 103 is proportional to the hydrogen gas concentration in contact with the sensor cell 103. As shown in (b) of FIG. 31, when the sensor cell 124 comes into contact with hydrogen gas, the sensor cell 124 becomes a semiconductor, and the resistance value of the detection film is significantly lower than that of the other sensor cells 103. As described above, when a bias voltage is applied from the bias power supply 111 to the sensor cell 103 having the detection film having a lowered resistance value, a large amount of current flows.

FIG. 32 is a block diagram showing the configuration of the gas detection device according to the seventh embodiment. A position detector 115 and a position detector 115 connected to the hydrogen gas detection sensor 110 are shown. Hereinafter, the operation of the gas detection device for detecting a gas leakage point will be described with reference to FIG. In FIG. 32, the sensor cell 103 is shown by an equivalent circuit.

Each sensor cell 103 is connected to a common electrode 102, and a bias voltage is applied from a bias power supply 111 via a current limiting resistor 112. Each sensor cell 103 is connected to each current-voltage conversion circuit 130 composed of an operational amplifier 113 and a feedback resistor 114 via each detection electrode 104. The current signal from each sensor cell 103 is converted into a voltage signal by each current-voltage conversion circuit 130 and input to the multiplexer 117. The multiplexer 117 selects one voltage signal from the voltage signals from each voltage-current conversion circuit 130 according to the control signal from the control circuit 119 received a command from the personal computer (hereinafter abbreviated as PC) 120, The voltage signal is input to the AZD conversion circuit 118. In the AZD conversion circuit 118, the voltage signal from the multiplexer 117 is converted from analog to digital by the control signal of the control circuit 119 that has received the command of the PC 120, and transmitted to the PC 120. The PC 120 performs arithmetic processing based on the signal from the AZD conversion circuit 118 and calculates a voltage value corresponding to the amount of current flowing through each sensor cell 103.

In the hydrogen gas detection operation, first, the one-dimensional array type hydrogen gas detection sensor 110 is in a state where it does not detect hydrogen gas. A voltage value corresponding to the amount of current flowing through each sensor cell 103 in that state is measured, and the measured value is recorded in PC 120 as an offset value of each sensor cell 103.

Next, with the one-dimensional array type hydrogen gas detection sensor 110 detecting hydrogen gas, a voltage value corresponding to the amount of current flowing through each sensor cell 103 is measured, and the measured value is measured for each sensor cell 103. Recorded in PC120 as measured value when hydrogen gas is detected. Then, the measured value force at the time of hydrogen gas detection of each sensor cell 103 accumulated in the PC 120 is also subtracted from the offset value, and the subtracted value is used as a change value of the output signal of the sensor cell 103 at the time of hydrogen gas detection. Record in PC 120. The change value of the output signal of each sensor cell 103 is a voltage value corresponding to the change of the electrical resistance value of each sensor cell 103, and is proportional to the detected hydrogen gas concentration.

By performing arithmetic processing as described above, one-dimensional array type hydrogen gas detection sensor 110 A distribution of change values of signals proportional to the concentration of hydrogen gas detected by each sensor cell 103 is obtained, and the position where hydrogen gas is detected can be calculated.

[0172] Next, an example of a method for calculating the position where hydrogen gas is detected will be described. First, when the detection position of hydrogen gas is one, a method is used in which the position of the sensor cell 103 having the largest change value of the output signal of each sensor cell 103 is set as the position where hydrogen gas is detected. This position is a position where the concentration of hydrogen gas is high.

When there are multiple hydrogen gas detection positions, the hydrogen gas is detected at the position of the sensor cell 103 that shows a value greater than the change value of the output signal of the adjacent sensor cell 103 in the three consecutively arranged sensor cells 103. The method of setting the position is used.

[0173] The experimental results in the one-dimensional array type hydrogen gas detection sensor 110 of Example 7 are shown in FIG.

This will be described with reference to (a) and (b).

FIG. 33 (a) is a cross-sectional view of the one-dimensional array type hydrogen gas detection sensor 110 used in this experiment. The configuration shown in (a) of FIG. 33 is basically the same as the configuration shown in FIG. 31 described above. As shown in FIG. 33 (a), the hydrogen gas detection sensor 110 used in this experiment has twelve sensor cells 103. In the following, each sensor cell 103 is given a number from X 1 to XI 2 in order of the one-end side force, and each sensor cell 103 is identified and described with that number.

FIG. 33 shows an example in which the one-dimensional array type hydrogen gas detection sensor 110 detects hydrogen gas at the sensor cell X3 and the sensor cell X8. The bias power supply 111 applies a DC voltage of 5 V to the common electrode 102. The current limiting resistor 112 is 10Ω. The bias current from each detection electrode 104 was about 1 A. The nozzle that ejects the gas to be detected, including hydrogen gas, has a circular shape with a gas outlet diameter of lmm, and the ejection direction is downward. In FIG. 33, the ejection direction is indicated by an arrow C, and the nozzles are arranged at positions where the gas to be detected is blown to the sensor cell X3 and the sensor cell X8. The gas to be detected was air containing 1% volume of hydrogen gas.

[0175] Fig. 33 (b) shows voltage values corresponding to the change values of the signals of the sensor cells XI to XI2 measured in this experiment. The sensor cell X3 and the sensor cell X8 in which the nozzle for ejecting the gas to be detected is arranged have a higher measured voltage value than the other sensor cells 103. Therefore, the one-dimensional array type hydrogen gas detection sensor used in this experiment It was confirmed that multiple hydrogen gas detection positions were accurately detected.

Next, a method for producing a one-dimensional array type hydrogen gas detection sensor used in this experiment will be described with reference to FIGS. 31 (a), (b) and (c).

[0176] As the base material 101 of the one-dimensional hydrogen gas detection sensor used in this experiment, quartz (SiO 2) having a length of 60 mm, a width of 5 mm, and a thickness of 0.5 mm was used. The base material 101 includes the sensor cell 103.

2

In order to form the through holes 106, 12 through holes having a diameter of 3 mm were formed at intervals of 5 mm.

The common electrode 102 on the back surface of the base material 101 was formed to a thickness of 0.5 m using gold (Au) by sputtering. The detection electrode 104 formed on the surface of the base material 101 has a length of 5 mm in the width direction of the base material 101 and a length of 4 mm in the longitudinal direction around each through-hole 106 using gold (Au) using a notch method. Twelve were formed with a length of 0.5 μm. Note that when sputtering the common electrode 102 and the detection electrode 104, masking was performed so that gold (Au) was not deposited inside the through hole 106.

[0177] Next, it is composed of platinum dispersion-supported tungsten trioxide (Pt—WO) serving as the sensor cell 103.

3 The sensing film to be formed was formed. A sol-gel method was used as a method for forming the detection film. Specifically, first, sodium tungstate dihydrate (Na WO 2Η Η: Pure Chemical Co., Ltd.)

2 4 2

41.2 g was taken in a volumetric flask, and pure water was added to prepare 250 mL to obtain a 0.5 mol / L colorless and transparent aqueous solution of sodium tungstate (Na 2 WO 3).

twenty four

[0178] Next, a cation exchange resin (Amberlite IR120B Na: manufactured by Organo Corporation) was packed into a column tower, and a sodium tungstate (Na W04) aqueous solution was passed through it.

2

Exchange sodium ions (Na +) in sodium acid (Na WO) aqueous solution with protons (H +),

twenty four

A pale yellow tungstic acid (H 2 WO 3) aqueous solution was obtained. Tungstic acid (H WO) aqueous solution

2 4 2 4

13 mL of catalytic metal hexacro-platinic acid (H PtCl 6Η Ο: Wako Pure Chemical Industries Ltd.

2 6 2

4mL of an aqueous solution in which 0.5molZL was dissolved in pure water and 8mL of ethanol were uniformly dispersed and mixed to synthesize a sol-gel solution of platinum-dispersed tungsten oxide.

[0179] The sol-gel solution was applied to the inner surface of the through-hole 106 of the substrate 101 and the surrounding lmm portion. The coating was performed by dipping the substrate 101 on which the portions other than the through hole 106 and the surrounding lmm were masked into the sol-gel solution. Base material 101 The rip time was about 20 seconds, and the substrate 101 was lifted from the sol-gel solution, and then nitrogen gas was blown to remove excess sol-gel solution.

Then, after drying at room temperature for 1 hour, the masking was removed, and further pre-baked at 200 ° C. for 1 hour using an electric furnace. After firing at 200 ° C. in this way, firing was performed at 500 ° C. for 3 hours and then cooled at room temperature. At this time, the thickness of the detection film of the sensor cell 103 is 0.3 μm.

In the one-dimensional array type hydrogen gas detection sensor 110 manufactured as described above, each resistance value between the common electrode 102 and each detection electrode 104 (hereinafter referred to as junction resistance) was measured. Each junction resistance was about 5 Ω.

FIG. 34 shows a one-dimensional array type hydrogen gas detection sensor 11 OA having a structure different from that of the one-dimensional array type hydrogen gas detection sensor 110 shown in FIG. 31 described above.

The one-dimensional array type hydrogen gas detection sensor 110A shown in FIGS. 34 (a) and 34 (b) has a common electrode 102, a sensor cell 103 on one surface (front surface) of an elongated substantially strip-like substrate 101. The detection film and the detection electrode 104 are formed. 34 (a) is a plan view of the hydrogen gas detection sensor 110A, and FIG. 34 (b) is a cross-sectional view of the hydrogen gas detection sensor 110A of FIG.

[0181] The one-dimensional array type hydrogen gas detection sensor 110A shown in FIG. 34 has a common electrode 102 on a part of the surface of a substantially strip-shaped quartz (SiO 2) base material 101 having electrical insulation properties. Formed

2

ing. The common electrode 102 has a predetermined width on the surface of the base material 101 and is formed in a substantially strip shape along the longitudinal direction. Further, on the surface of the base material 101, a plurality of sensor cells 103, which are detection films of platinum-dispersed supported tandane trioxide (Pt—WO) that changes from an electrically insulated state to a semiconductor state when hydrogen gas is detected, are provided. Formed in the minute area of

Three

Yes. The sensor cells 103 are arranged in a substantially straight line with a predetermined interval, and one end of all the sensor cells 103 is arranged to be electrically connected to the common electrode 102. Furthermore, detection electrodes 104 are formed on the surface of the substrate 101 corresponding to the sensor cells 103. Each detection electrode 104 is paired with the common electrode 102 with the sensor cell 103 in between, and each detection electrode 104 and the common electrode 102 are connected via the sensor cell 103. The detection area of hydrogen gas in the sensor cell 103 is the same as that of the sensor cell 103 and the common electrode 101. Between the sensor cell 103 and the detection electrode 104. One end of the lead line 108 that outputs a current signal as a detection signal is connected to the end of each detection electrode 104, and the other end is connected to the current-voltage conversion circuit 130 (see FIG. 32) of the position detection device 115. . In the one-dimensional array type hydrogen gas detection sensor 110A of FIG. 34 configured as described above, the common electrode 102 is connected to the bias power supply 111 via the current limiting resistor 112, and FIG. Similar to the hydrogen gas detection sensor 110 shown, the hydrogen gas contained in the gas to be detected can be detected.

[0182] The one-dimensional array type hydrogen gas detection sensor 110A of Fig. 34 has a configuration that does not require a through hole and has a simple structure. However, since the hydrogen gas detection sensor 110A in FIG. 34 does not have a function of discharging the gas to be detected including hydrogen gas from the front surface to the back surface of the base material 101, the hydrogen gas is detected on the surface of the base material 101. The range of the sensor cell that has diffused and detected hydrogen gas tends to expand, and the detection accuracy of the hydrogen gas detection position may be reduced.

In the configuration shown in FIG. 34, it is of course possible to improve the hydrogen gas detection sensitivity by forming through holes for discharging the gas to be detected with appropriate intervals. Note that the position of the through hole may be provided on the sensor cell 103 or may be provided elsewhere.

FIG. 35 is a block diagram showing a gas detection device using position detection device 115 A having a configuration different from that of position detection device 115 shown in FIG. 32 described above.

A method for calculating the hydrogen gas detection position by the one-dimensional array type hydrogen gas detection sensor 110 in the gas detection device shown in FIG. 35 will be described below. The position detection device 115A shown in FIG. 35 has a single current-voltage conversion circuit 130 and has a feature that a simple circuit configuration can be realized.

As the one-dimensional arrangement type hydrogen gas detection sensor 110 shown in FIG. 35, any structure of the one-dimensional arrangement type hydrogen gas detection sensor shown in FIG. 31 and FIG. 34 described above can be used. . In FIG. 35, the sensor cell 103 is shown by an equivalent circuit.

[0184] The detection electrode 104 connected to each sensor cell 103 is connected to a plurality of terminals of a detection switch 134 which is a switching switch. The common terminal of the detection switch 134 is connected to the bias power supply 111 via the current limiting resistor 112. Detection switch 134 It is connected to a personal computer (hereinafter abbreviated as PC) 120 via a control circuit 119, and has a function of applying a bias voltage to any one sensor cell 103 in accordance with a command from the PC 120. The common electrode 102 connected to each sensor cell 103 is connected to a current-voltage conversion circuit 130 composed of a feedback resistor 114 and an operational amplifier 113. The current / voltage conversion circuit 130 is connected to the AZD conversion circuit 118 controlled by the PC 120. The output of the AZD conversion circuit 118 is input to the PC 120.

As described above, in the one-dimensional array type gas detection device shown in FIG. 35, the connection directions of the common electrode 102 and the detection electrode 104 in the hydrogen gas detection sensor shown in FIGS. 31 and 34 are different.

Next, the operation principle of the position detection device 115A shown in FIG. 35 will be described.

First, the one-dimensional array type hydrogen gas detection sensor 110 is in a state where it does not detect hydrogen gas. In a state where the hydrogen gas is not detected, the PC 120 switches the detection switch 134 and applies a bias voltage to the sensor cell 103 to be measured. Each sensor cell 103 to which the bias voltage has been applied detects the hydrogen gas based on the bias voltage, and outputs a current (= bias current) of the state to the current-voltage conversion circuit 130. The current-voltage conversion circuit 130 converts the bias current into a voltage signal, which is converted into a voltage signal and input to the / D conversion circuit 118. The AZD conversion circuit 118 converts the input voltage signal into a digital signal and transmits it to the PC 120. The PC 120 records a digital signal corresponding to the bias current of the sensor cell 103 to which the bias voltage is applied as an offset value. The PC 120 sequentially switches the detection switches 134 in this way, and records the offset values of all the sensor cells 103.

Next, the one-dimensional array type hydrogen gas detection sensor 110 is in a state of detecting hydrogen gas. In the state of detecting this hydrogen gas, the PC 120 switches the detection switch 134 and sequentially applies a bias voltage to the sensor cell 103 to be measured. At this time, each sensor cell 103 to which the bias voltage is applied outputs a current signal in a state of detecting hydrogen gas to the current-voltage conversion circuit 130. The current / voltage conversion circuit 130 converts the current signal to form a voltage signal and outputs the voltage signal to the AZD conversion circuit 118. The AZD conversion circuit 118 converts the input voltage signal into a digital signal and transmits it to the PC 120. PC120 A digital signal corresponding to the current signal of the sensor cell 103 to which the false voltage is applied is recorded as a measurement value when hydrogen gas is detected. The PC 120 sequentially switches the detection switches 134 in this way, and records the measurement values when all the sensor cells 103 detect the hydrogen gas.

[0186] Next, the PC 120 subtracts the offset value from the measured value when the hydrogen gas is detected in each sensor cell 103. Then, the PC 120 records the subtracted value in the PC 120 as a change value of the output signal of the sensor cell 103 when hydrogen gas is detected. The change value of the output signal of each sensor cell 103 is a voltage value corresponding to the change of the electrical resistance value of each sensor cell 103, and is proportional to the detected hydrogen gas concentration.

Next, an example of a method for calculating the position where hydrogen gas is detected will be described. First, when the detection position of hydrogen gas is one, a method is used in which the position of the sensor cell 103 having the largest change value of the output signal of each sensor cell 103 is set as the position where hydrogen gas is detected. This position is a position where the concentration of hydrogen gas is high.

As described above, the position detection device 115A having the configuration shown in FIG. 35 can be used to calculate the hydrogen gas detection position of the one-dimensional array type hydrogen detection sensor with high accuracy.

Example 8

Next, a gas detection apparatus according to Example 8 of the present invention will be described. The gas detection apparatus according to the eighth embodiment includes the one-dimensional array type hydrogen gas detection sensor 110 and the position detection apparatus 115B described in the seventh embodiment. The position detection device 115B in the gas detection device of the eighth embodiment has a one-dimensional resistance division type configuration and can be configured with a simple circuit.

The configuration of the gas detector of Example 8 will be described with reference to FIG. FIG. 36 is a block diagram illustrating a configuration of the gas detection device according to the eighth embodiment. The one-dimensional arrangement type hydrogen gas detection sensor 110 in the eighth embodiment has the same structure as the one-dimensional arrangement type hydrogen gas detection sensor shown in FIGS. 31 and 34 in the seventh embodiment. Detecting power connected to each sensor cell 103 (shown as an equivalent circuit in FIG. 36) of the one-dimensional array type hydrogen detecting sensor 110 The pole 104 is connected to the adjacent detection electrode 104 via a current dividing resistor 141. The output signals of the detection electrodes 104 at both ends of the one-dimensional array type hydrogen gas detection sensor 110 are connected to be input to the current-voltage conversion circuit 130a or the current-voltage conversion circuit 130b. On the other hand, the common electrode 102 is connected to a bias power supply 111 via a current limiting resistor 112.

[0189] The output signals of the current-voltage conversion circuits 130a and 130b are input to the AZD conversion circuits 118a and 118b, and the analog signal power is also converted into digital signals. The digital signals output from the Α / Ό conversion circuits 118a and 118b are input to the adder 130 and the divider 139, respectively. Further, each digital signal from the adder 138 and the divider 139 is converted from a digital signal to an analog signal in the DZA conversion circuits 140a and 140b, respectively. The voltage signal from the DZA conversion circuit 140a is output as the first output 142, and the voltage signal from the DZA conversion circuit 140b is output as the second output 143.

Next, the operation principle of the position detection device 115B in Embodiment 8 will be described using FIG.

As described above, the detection electrode 104 of the one-dimensional array type hydrogen gas detection sensor 110 is connected to the adjacent detection electrode 104 by the current dividing resistor 141. The detection electrodes 104 at both ends of the one-dimensional array type hydrogen gas detection sensor 110 are connected to the inputs of the current-voltage conversion circuits 130a and 130b. The output current from each detection electrode 104 is current-divided by a current dividing resistor 141 connected between the current-voltage conversion circuit 130a and the current-voltage conversion circuit 130b, and the current-voltage conversion circuit 130a and the current-voltage conversion circuit 130b. Is input.

[0191] In Example 8, the current flowing through the current-voltage conversion circuit 130a is Ilb and the current flowing through the current-voltage conversion circuit 130b is I2b when the one-dimensional array type hydrogen gas detection sensor 110 is not detecting hydrogen gas. And The currents lib and I2b are converted into voltage signals in the current-voltage conversion circuit 130a and the current-voltage conversion circuit 130b. The converted voltage signal is sent to the AZD conversion circuit 118a and the AZD conversion circuit path 118b to be converted into a digital signal. The converted digital signal is sent to an adder 138 and a divider 139. The adder 138 and divider 139 detect the hydrogen gas from each digital signal at this time. Hold as a value corresponding to bias currents I lb and I2b in an unknown state.

Next, assume that the sensor cell 103 of the one-dimensional array type hydrogen gas detection sensor detects hydrogen gas. It is assumed that the current flowing through the current-voltage conversion circuit 130a in the state where the hydrogen gas is detected is II, and the current flowing through the current-voltage conversion circuit 130b is 12. Similar to the bias current described above, currents II and 12 are converted to digital signals after current-voltage conversion and sent to adder 138 and divider 139. In the adder 138 and the divider 139, the digital signals corresponding to the bias currents lib and I2b held are also subtracted from the digital signal forces corresponding to the currents II and 12 when hydrogen gas is detected, respectively. The adder 138 and the divider 139 perform addition and division arithmetic processing corresponding to the following equations (22) and (23). The calculation results of these additions and divisions are output as digital electrical signals, and are output as analog electrical signal calculation results E1 and E2 by the DZA conversion circuits 140a and 140b.

[0193] El = k31 X {(I1— lib) + (12— I2b)} (22)

[0194] E2 = k32 X (12—I2b) / {(ll—lib) + (12—I2b)}

(twenty three)

[0195] k31 and k32 in equations (22) and (23) are constants.

In the above (22) and (23), the calculation result E1 is substantially proportional to the concentration and area of the hydrogen gas in contact with the sensor cell 103, and the calculation result E2 indicates the position of the sensor cell 103 that has detected hydrogen gas.

As a calculation formula indicating the hydrogen gas detection position, in addition to the above formula (23), the following formula (24) or formula (25) can be used.

[0196] E3 = k33 X (12—I2b) Z (Il—lib) (24)

[0197] E4 = k34 X [{(I2—I2b)-(II— lib)} /

{(II— Ilb) + (I2— I2b)}] (25)

[0198] In equations (23), (24), and (25), the currents II and 12 when the sensor cell 103 with the sensing film detects hydrogen gas are sufficiently larger than the bias currents lib and I2b. In such a case, the bias current lib and I2b can be ignored for calculation. In that case, Equation (23), Equation (24), and Equation (25) are converted into the following Equation (26), Equation (27), and Equation (28). It becomes.

[0199] E2 = k32 X I2 / (11 +12) (26)

[0200] E3 = k33 X I2 / ll (27)

[0201] E4 = k34 X (12— II) / (II +12) (28)

[0202] In the eighth embodiment, the power bias power supply 111 described in the example in which the DC power supply is used as the bias power supply 111 is not limited to the DC power supply, and may be an AC power supply of about IKHz to ΙΟΚΗζ. In that case, it is necessary to add a rectification function to the current-voltage conversion circuits 130a and 130b of the position detection device 115B.

In the eighth embodiment, the position detection device 115B is configured to convert the output current from the hydrogen gas detection sensor 110 into a digital signal and perform arithmetic processing. However, the position detection device 115B is not converted into a digital signal but in an analog signal state. A circuit configuration for calculation may be used.

Example 9

[0203] Next, a hydrogen gas detection sensor of Example 9 according to the present invention will be described with reference to FIGS. In the hydrogen gas detection sensor of Example 9, the hydrogen gas detection region is two-dimensional, and a plurality of sensor cells are arranged in a two-dimensional plane.

The two-dimensional array type hydrogen gas detection sensor of Example 9 is a detection film of a plurality of minute regions in which an electrical resistance value changes when hydrogen gas is detected on a substantially rectangular and electrically insulating base material. Are arranged in a two-dimensional lattice pattern at approximately equal intervals in the row and column directions. In the hydrogen gas detection sensor of Example 9, the position where hydrogen gas is detected is calculated from the change in the resistance value of the detection film in a plurality of minute regions.

[0204] FIG. 37 is a diagram showing the structure of the two-dimensional array type hydrogen gas detection sensor of Example 9, (a) is a plan view, and (b) is the hydrogen gas detection shown in (a). FIG. 6 is a cross-sectional view taken along line Y—Y in the sensor.

The two-dimensional array-type hydrogen gas detection sensor 125 of Example 9 is formed in a substantially rectangular shape and is made of an electrically insulating quartz (SiO 2) base material 101 and is connected to the surface of the base material 101 in the column direction.

2

Common detection electrode 133, common detection electrode 132 connected to the back surface of substrate 101 in the row direction, and detection connected to common detection electrodes 132, 133 formed on the inner surface of the through-hole and on the front and back of substrate 101 And a sensor cell 103 having a film. [0205] The detection film constituting the sensor cell 103 is composed of platinum-dispersed tungsten trioxide (Pt—WO) that changes its state from an electrically insulating state to a semiconductor state when hydrogen gas is detected.

3 has been done. The detection film of the sensor cell 103 is formed on the inner surface of the through hole 106 penetrating the front and back of the base material 101, and is formed on the back side of the base material 101 and the common detection electrode 133 in the row direction formed on the surface of the base material 101. It is joined to the common detection electrode 132 in the column direction. In the base material 101, the through holes 106 are formed at the intersections of two-dimensional lattices that are equally spaced in the row and column directions that are substantially perpendicular to each other. Therefore, the sensor cells 103 formed in the through holes 106 are in a two-dimensional array (planar array).

On the back surface of the substrate 101, a plurality of common detection electrodes 132 in the row direction are formed so as to connect one end of each sensor cell 103 arranged in a straight line in the row direction. Further, on the surface of the substrate 101, a plurality of common detection electrodes 133 in the column direction are formed so as to connect a part of the sensor cells 103 arranged in a straight line parallel to the column direction.

As shown in FIG. 37 (a), in the two-dimensional array type hydrogen gas detection sensor 125 of Example 9, the common detection electrode 132 in the row direction and the common detection electrode 133 in the column direction are It is connected to each lead line 108 provided on the end face of the base 101.

By forming the through hole 106, it is possible to discharge the hydrogen gas 126 of the gas to be detected contacting the surface side of the substrate 101 to the back surface of the substrate 101 through the through hole 106. Thus, by forming the through hole 106 penetrating to the back surface of the base material 101 at the center of the sensor cell 103, the surface force of the base material 101 is prevented from diffusing along the surface of the base material 101, An increase in the range of the sensor cell 103 in contact with the hydrogen gas can be prevented. The through hole 106 is an area where the sensor cell 103 is not formed as long as it is a hole penetrating from the front surface to the back surface of the base material 101, and is a part of the base material 101 or a common detection electrode in the row direction and the column direction. You can place it in the part!

[0207] As shown in FIG. 37 (a), the common detection electrode 132 in the row direction is provided from the row Y1 to the row Yn, and the common detection electrode 133 in the column direction is provided from the column XI to the column Xm. ing. The display of each sensor cell 103 is indicated by (Xi, Yj) using the common detection electrode 132 in the row direction and the common detection electrode 133 in the column direction which are placed at the position of the sensor cell 103 to be displayed. This Where i is in the range of 1 to m and j is in the range of 1 to n.

[0208] The substrate 101 can be used as long as it is a material having electrical insulation and is stable at a heating temperature of 500 ° C when the sensor cell 103 is sintered. Specific materials for the substrate 101 include silicon (SiO 2), aluminum nitride (A

twenty two

IN), alumina (Al 2 O 3), and the like can be used. In addition, as a rosin-based material, Nikko

twenty three

A heat-resistant phenolic material such as Tymold from Kasei Co., Ltd. can also be used. In this case, a three-dimensional shape other than a flat surface can be obtained by using an injection molding method. Furthermore, as a flexible sheet-like material, polyimide-based materials such as Kapton (registered trademark) of Toray DuPont Co., Ltd. can be used. Polyimide materials can be used when the sintering temperature of the force sensor cell 103, which has a maximum heat-resistant temperature of about 450 ° C, is about 450 ° C.

[0209] The common detection electrode 132 in the row direction and the common detection electrode 133 in the column direction are materials having high conductivity, and can be used as long as they are stable at the sintering temperature of the sensor cell 103 of about 500 ° C. In addition, it is more desirable that the common detection electrode itself is inert to the combustible gas containing hydrogen atoms in the gas to be detected. Common sensing electrodes 132 and 133 are made of highly conductive materials such as magnesium (Mg), aluminum (A1), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), and nickel. It is possible to use metals such as (Ni) and silver (Ag), and carbon (C). In particular, as the material of the common detection electrodes 132 and 133, gold (Au) and copper (Cu) that are inert to hydrogen gas are desirable.

[0210] The sensor cell 103 can be any material that has a property that its electrical characteristics change when it comes into contact with hydrogen gas. For example, tin oxide (SnO), molybdenum trioxide

2

Buden (MnO), tungsten trioxide (WO), titanium dioxide (TiO), iridium hydroxide

2 3 2

(Ir (OH) n), vanadium pentoxide (V O), rhodium oxide (Rh O · χΗ Ο), etc.

2 5 2 3 2

Is possible. In addition, organic substances such as pyrrolopyrrole, which is a pigment of paint, mixed with nitrogen gas can also be used. In particular, when pyrrolopyrrole is used, it can be used only by natural drying. In this case, since a sintering process of about 500 ° C. is not required, the range of materials selection such as the base material 101 and the electrode is greatly expanded.

[0211] [Operation principle of hydrogen gas sensor] Next, the operation principle of hydrogen gas detection of the hydrogen gas detection sensor of Example 9 will be described.

In FIG. 37, the case where the hydrogen gas 126 contained in the gas to be detected comes into contact with the sensor cell 124 formed of platinum dispersion-supported tungsten trioxide V at the position indicated by the arrow C will be described. The platinum dispersion supported tungsten trioxide (Pt-WO) constituting the sensor cell 103 has platinum (Pt) fine particles having a particle diameter of about 1 nm to 10 nm as a catalyst.

Three

Dispersion supported on tungsten trioxide (WO) particles with a particle size of about 1 OOnm from Onm

Three

With a structured. On the platinum (Pt) fine particles, the hydrogen gas 126 is dissociated into protons (H +) and electrons (e—). The dissociated proton (H +) spills over the platinum catalyst fine particles and diffuses into the tungsten trioxide (WO), which is the main component of the sensor cell 103.

Three

Form bronze. Tungsten trioxide (WO) forms tungsten bronze

Three

In a state where it is not, it is a state that is electrically close to insulation. However, tandane trioxide (WO) becomes a semiconductor when protons (H +) diffuse and form tungsten bronze.

Three

In addition, when the concentration of hydrogen gas increases and many protons (H +) diffuse, the properties of a semiconductor close to that of a conductor are exhibited.

[0212] In general, the resistance value of the sensor cell 103 is proportional to the concentration of hydrogen gas in contact with the sensor cell 103. As described above, the sensor cell 124 in contact with the hydrogen gas is made into a semiconductor, has a resistance value lower than that of the other sensor cells 103, and a large amount of current flows when a bias voltage is applied from the bias power supply 111.

FIG. 38 is a block diagram showing a gas detection apparatus having a current-voltage conversion circuit 130 to which a signal from the two-dimensional array type hydrogen gas detection sensor 125 of Example 9 is inputted.

In FIG. 38, each sensor cell 103 of the two-dimensional array type hydrogen gas detection sensor 125 (in FIG. 38, the sensor cell 103 is shown by an equivalent circuit) is connected to the common detection electrode 132 in the corresponding row direction and the corresponding column direction. The common detection electrode 133 is connected. The common detection electrode 132 in each row direction is connected to the corresponding detection switch 134 and further connected to the bias power supply 111 via the current limiting resistor 112. The common detection electrode 133 in each column direction is connected to the corresponding current-voltage conversion circuit 130. The current signal from the common detection electrode 133 in each column direction is converted into a voltage signal and input to the multiplexer 117. Maru The chiplexer 117 selects one voltage signal from the voltage signals from each current-voltage conversion circuit 130 according to the control signal of the control circuit 119 that receives a command from the personal computer (hereinafter abbreviated as PC) 120. The selected voltage signal is input to the AZD conversion circuit 118. In the AZD conversion circuit 118, the signal from the multiplexer 117 is converted from analog to digital by the control signal of the control circuit 119 that has received a command from the PC 120, and transmitted to the PC 120. The PC 120 performs arithmetic processing based on the signal from the AZD conversion circuit 118, and calculates a voltage value corresponding to the amount of current flowing through each sensor cell 103.

[0214] Next, the operation in the case of performing arithmetic processing based on the signal from the two-dimensional array type hydrogen gas detection sensor will be described.

First, a two-dimensional array type hydrogen gas detection sensor detects hydrogen gas and puts it into a state. A detection switch 134 corresponding to the common electrode 132 in the row direction to be measured is connected. Then, a voltage value corresponding to the amount of current flowing through the common electrode 132 in each column direction is measured. At this time, the position of the sensor cell measured from the row number Yj of the common electrode 132 in the row direction to which the detection switch 134 is connected and the column number XI of the common electrode 133 in the column direction for which the voltage measurement was performed by the multiplexer 117 is performed. (Xi, Yj) representing the position information and the offset value of the sensor cell 103 are recorded. Similarly, the detection switches 134 are sequentially switched, and the positional information and offset values of all sensor cells 103 are associated and recorded.

[0215] After that, the voltage corresponding to the amount of current flowing through all the sensor cells 103 is obtained in the same manner as the method of recording the offset value described above in the state where the hydrogen gas detection sensor of the two-dimensional array type detects hydrogen gas. Measure the value. The position information and measurement values of each sensor cell 103 measured at this time are recorded in the PC 120 as measurement values when hydrogen gas is detected. After that, for each sensor cell 103 stored in the PC 120, the measured value force when hydrogen gas is detected is also subtracted from the offset value and recorded in the PC 120 as the change value of the output signal of each sensor cell 103. The change value of the output signal of each sensor cell 103 is a voltage value corresponding to the change of the electrical resistance value of each sensor cell 103, and is proportional to the detected hydrogen gas concentration.

As a result, a distribution of signal change values proportional to the hydrogen gas concentration detected by each sensor cell 103 of the two-dimensional array type hydrogen gas detection sensor is obtained, and the hydrogen gas detection position is calculated. Can be issued.

[0216] The experimental results using the gas detector of Example 9 will be described with reference to (a) and (b) of FIG.

FIG. 39 (a) is a plan view of the two-dimensional array type hydrogen gas sensor used in this experiment. This two-dimensional array type sensor is basically the same as the hydrogen gas detection sensor 125 described with reference to FIG.

As shown in (a) of FIG. 39, the hydrogen gas detection sensor 125 used in this experiment has 144 sensor cells 103 having 12 rows in the row direction and 12 columns in the column direction. Hereinafter, common detection electrodes 132 in the row direction are numbered from Y1 to Y12 from one end, and common detection electrodes 133 in the column direction are numbered from XI to XI2 from one end. Thus, the sensor cells 103 arranged at the intersections in the row direction and the column direction are identified and described by their numbers (Xi, Yj). I and j are in the range of 1-12.

[0218] In this experiment, the bias voltage 111 was a DC voltage of 5V, and was applied to the common detection electrode 132 in the row direction via the detection switch 134. The current limiting resistor 112 is 10 Ω. The bias current from the common detection electrode 133 in each column direction was almost constant and about: LA. The nozzle that ejects the gas to be detected, including hydrogen gas, was circular with a gas outlet diameter of lmm, and the ejection direction was upward. Three nozzles were placed at a distance of lmm below the sensor cell (X4, Y4), sensor cell (X6, Y6), and sensor cell (X9, Y8). The gas to be detected was air containing 1% hydrogen gas.

[0219] (b) of FIG. 39 shows a voltage value which is a change value of the output signal of each sensor cell 103. The voltage of the sensor cell (X4, Y4), sensor cell (Χ6, および 6) and sensor cell (Χ9, Υ8), where the nozzles for injecting the gas to be detected are located close to each other, are the voltage values of the other sensor cells 103. It is getting higher. Therefore, it was confirmed that the detection position of multiple hydrogen gases was accurately detected.

[0220] Next, a method for producing a two-dimensional array type hydrogen gas detection sensor used in the experiment will be described.

Quartz (SiO 2) having a length of 65 mm, a width of 65 mm, and a thickness of 0.5 mm was used for the base material 101 of the two-dimensional array type hydrogen gas detection sensor of Example 9 used in this experiment. For base material 101 In order to form the sensor cell 103, 144 through-holes 106 having a diameter of 3 mm were formed in a lattice form at intervals of 5 mm in length and width.

[0221] The common detection electrode 132 in the row direction on the back surface of the substrate 101 is formed with a width of 4 mm, a length of 65 mm, and a thickness of 0.5 μm around the through-hole 106 by sputtering gold (Au). did. The common detection electrode 133 in the row direction on the surface of the base material 101 was formed with a width of 4 mm, a length of 65 mm, and a thickness of 0.5 m around the through hole 106 by using a sputtering method of gold (Au). The common detection electrode 132 in the row direction and the common detection electrode 133 in the column direction were formed by sputtering using a mask so that gold (Au) was not deposited inside the through hole 106.

[0222] Next, the inner surface of the through-hole 106 is composed of platinum dispersion-supported trioxide-tungsten (Pt—WO).

3 The formed sensing film was formed. A sol-gel method was used as a method for forming the detection film. Specifically, first, sodium tungstate dihydrate (Na WO · 2Η Ο: Pure Chemical)

2 4 2

(Made by Co., Ltd.) 41. 2 g was taken in a volumetric flask, and pure water was added to prepare 250 mL to obtain a 0.5 mol ZL colorless and transparent aqueous solution of sodium tungstate (Na 2 WO 3).

twenty four

[0223] Next, cation exchange resin (Amberlite IR120B Na: manufactured by Organo Corporation) was packed in a column tower, and a sodium tungstate (Na 2 WO) aqueous solution was passed through it.

twenty four

2 4 2 4

2 6 2

[0224] The above sol-gel solution was applied to the inner surface of through-hole 106 and the portion of 0.5 mm around through-hole 106 on the front and back surfaces of substrate 101. The coating was performed by dipping the substrate 101 masked with the portion other than the through-hole 106 and the surrounding area of 0.5 mm into the sol-gel solution. The dip time of the base material 101 was about 20 seconds. The base material 101 was lifted from the sol-gel solution, and then nitrogen gas was blown to remove excess sol-gel solution.

[0225] Further, after drying at room temperature for 1 hour, the masking was removed, and calcining was performed at 200 ° C for 1 hour using an electric furnace. After calcining at 200 ° C for 1 hour, it was further calcined at 500 ° C for 1 hour and then cooled at room temperature. At this time, the sensor cell 103 is located between the front surface and the back surface of the base material 101. The shape of the connecting through hole 106 is obtained. The film thickness of the sensor cell 103 was 0.5 m. For each sensor cell 103 fabricated as described above, a resistance value (hereinafter referred to as a junction resistance) between the common detection electrode 132 in the row direction and the common detection electrode 133 in the column direction was measured. The junction resistance of each sensor cell 103 was about 5ΜΩ on average and was almost uniform.

FIG. 40 is a view showing a hydrogen gas detection sensor 125A having a configuration different from that of the hydrogen gas detection sensor shown in FIG. 37, wherein (a) is a plan view and (b) is shown in (a). FIG. 4 is a cross-sectional view of the hydrogen gas detection sensor 125A taken along line ZZ. The two-dimensional array type hydrogen gas detection sensor 125A shown in FIG. 40 has almost the same structure as the hydrogen gas detection sensor 125 shown in FIG. 37. The difference is that there is no through-hole for discharging. However, the hydrogen gas detection sensor 125A in FIG. 40 has the same basic function as the two-dimensional array type hydrogen gas detection sensor 125 in FIG. However, the surface force of the base material 101 also has a function of discharging the gas to be detected including hydrogen gas to the back surface. Therefore, the sensor cell in which the hydrogen gas diffuses on the surface of the base material 101 and the hydrogen gas is detected. The detection range of the hydrogen gas detection position may be reduced.

Example 10

[0227] Next, a gas detector of Example 10 according to the present invention will be described. The gas detection device according to the tenth embodiment is a gas detection device configured using the two-dimensional array type hydrogen gas detection sensor 125 described with reference to FIGS. 35 and 36 in the ninth embodiment. The gas detection device of Example 10 uses a two-dimensional resistance division type position detection device. The position detection device used in the gas detection device of Example 10 has a feature that can be configured with a simple circuit.

FIG. 41 is a block diagram showing the configuration of the gas detection device according to the tenth embodiment.

The two-dimensional array type hydrogen gas detection sensor 125 is provided with a two-dimensional resistance division type position detection device 115C.

The common detection electrode 133 in the column direction is connected to the common detection electrode 133 in the adjacent column direction by a current dividing resistor 141. The common detection electrodes 133 in the column direction at both ends become the output electrodes Xa and Xb in the column direction of the hydrogen gas detection sensor 125.

On the other hand, the common detection electrode 132 in the row direction is electrically connected to the common detection electrode 132 in the adjacent row direction. They are connected by a flow dividing resistor 141. The common detection electrodes 132 in the row direction at both ends become the output electrodes Ya and Yb in the row direction of the hydrogen gas detection sensor 125.

The output electrodes Xa, Xb, Ya and Yb are connected to the current-voltage conversion circuits 130a, 130b, 130c and 130d, respectively. The current-voltage conversion circuits 130a and 130b are configured by using operational amplifiers, and output electrodes Xa and Xb are connected to the inverting input terminals of the operational amplifiers, respectively. In addition, a noise power supply 111 is connected to the non-inverting input terminal. The operational amplifiers of the current-voltage conversion circuits 130a and 130b apply a bias voltage for detecting a change in resistance of the sensor cell 103 to the two-dimensional array type hydrogen gas detection sensor via the output electrodes Xa and Xb. The outputs of the operational amplifiers of the current-voltage conversion circuits 130a and 130b are input to the addition / subtraction circuits 135a and 135b for removing the bias voltage and for reversing the voltage, respectively. The outputs of the addition / subtraction circuits 135a and 135b are input to the AZD conversion circuit 118.

[0230] The current-voltage conversion circuits 130c and 130d are configured using operational amplifiers, and output electrodes Ya and Yb are connected to the inverting input terminals of the operational amplifiers, respectively. The non-inverting input terminal of this operational amplifier is grounded. Outputs from the current-voltage conversion circuits 130c and 130d are input to the AZD conversion circuits 118c and 118d, respectively. Outputs from the AZD conversion circuits 118a and 118b are input to a divider 139a and an adder 138, respectively. On the other hand, outputs from the AZD conversion circuits 118c and 118d are input to the divider 139b and the adder 138, respectively. Outputs from the dividers 139a and 139b and the adder 138 are input to the DZA conversion circuits 140a, 140b, and 140c, and converted into a digital signal power S analog signal.

Next, the operation principle of the position detection device 115C in Embodiment 10 will be described.

When all the sensor cells 103 detect the hydrogen gas !, the current flowing to the electrode Xa is Iab, the current flowing to the electrode Xb is Ibb, the current flowing to the electrode Ya is Icb, and the electrode Xb is Let Idb be the flowing current. At this time, the currents lab, Ibb, Icb and Idb are converted into current-voltage conversion circuits 130a, 130b, 130c and 130d. The voltage signals of the current-voltage conversion circuits 130a and 130b are input to the addition / subtraction circuits 135a and 135b, respectively, and the bias voltage generated by the bias power supply 111 is subtracted, and further the voltage signal The sign of is reversed. As a result, the voltage has the same polarity as the current-voltage conversion circuits 130c and 130d.

[0232] The signals from the addition / subtraction circuits 135a and 135b and the current-voltage conversion circuits 130c and 130d are converted into digital signals by the AZD conversion circuits 118a, 118b, 118c and 118d. The converted digital signal is sent to dividers 139a and 139b and adder 138. Dividers 139a and 139b and adder 138 hold the digital signals in this state as values corresponding to bias currents lab, Ibb, Icb, and Idb.

Next, it is assumed that the sensor cell 103 of the two-dimensionally arranged hydrogen gas detection sensor 125 in Example 10 has detected hydrogen gas. In this state, the current flowing through the electrode Xa is Ia, the current flowing through the electrode Xb is Ib, the current flowing through the electrode Ya is Ic, and the current flowing through the electrode Yb is Id.

Similarly to the bias current described above, the currents la, lb, Ic, and Id are converted into current signals, converted into digital signals, and the digital signals are sent to the dividers 139a and 139b and the adder 138. In the dividers 139a and 139b and the power calculator 138, the digital signals corresponding to the bias currents lab, Ibb, Icb, and Idb that have been held are converted into digital signals corresponding to la, lb, Ic, and Id, respectively. Subtraction is performed, and arithmetic processing is performed by addition and division corresponding to equations (29) to (31) below. The calculation results of these additions and divisions are output as digital electric signals, and the D, A conversion circuits 140a, 140b, and 140c calculate the analog electric signals E5, the calculation results by the X direction division, and the E6X and Y direction divisions Calculated by E7Y. The calculation result E6X in the X direction is a calculation result indicating the detection position of the hydrogen gas in the X direction, and the calculation result E7Y in the Y direction is a calculation result indicating the detection position of the hydrogen gas in the Y direction.

[0234] E5 = k35 X ((la lab) + (lb Ibb) + (Ic Icb)

+ (Id— Idb) (29)

[0235] E6X = k36 X (lb -Ibb) / {(la -lab) + (lb -Ibb)}

(30)

[0236] E7Y = k37 X (Id— Idb) Z {(Ic— Icb) + (Id -Idb)}

(31) In formulas (29), (30), and (31), k35, k36, and K37 are constants.

[0238] Next, an explanation will be given using an arithmetic expression using V for division indicating the hydrogen gas detection position other than the arithmetic processing of Expression (30) and Expression (31).

In the formula, the X direction contains (la—lab) and (lb—Ibb), and the Y direction contains the ratio of (Ic – Icb) and (Id—Idb)! / It can be used as an arithmetic expression indicating the detection position. An example of a calculation method that indicates a specific hydrogen gas detection position is described below.

[0239] E8X = k38 X (lb— Ibb) Z (Ia— lab) (32)

[0240] E9Y = k39 X (Id— Idb) Z (Ic— Icb) (33)

[0241] Equations (32) and (33) are constants, k38 and k39i.

[0242] E10X = k40 X [{(Ib—Ibb)

One (la— lab)} / {(la— lab) + (lb— Ibb)}]

(34)

[0243] El lY = k41 X [{(Id-Idb)

(lc-Icb)} / {(lc-Icb) + (Id-Idb)}]

(35)

[0244] In the equations (34) and (35), k40 and k41 are constants.

As described above, hydrogen gas detection can be performed using the arithmetic expression of the expression (32) and the force expression (35) in addition to the arithmetic expressions of the above expressions (30) and (31).

In addition, in equations (29) to (35), if the output currents la, lb, Ic and Id force bias currents of the hydrogen gas detection sensor 125 are sufficiently large with respect to lab, Ibb, Icb and Idb, It is possible to calculate by ignoring the current. In this case, equations (29) to (35) are expressed by the following equation (36) and force equation (42).

[0245] E5 = k35 X (Ia + Ib + Ic + Id) (36)

[0246] E6X = k36 X Ib / (lb + Ia) (37)

[0247] E7Y = k37 X Id / (Ic + Id) (38)

[0248] E8X = k38 X Ib / la (39)

[0249] E9Y = k39 X Id / lc (40) [0250] E10X = k40 X (lb-la) / (la + lb) (41)

[0251] El lY = k41 X (ld-Ic) / (lc + Id) (42)

[0252] In equation (36) force equation (42)! /, K35, k36, k37, k38, k39, k40, k41i are constants.

As described above, in the two-dimensional array type hydrogen gas detection sensor of Example 10 shown in FIG. 41, V, the hydrogen gas detection position should be calculated using Equation (29) and Equation (42) as well. Can do.

The bias power supply 111 used in the gas detection apparatus of the tenth embodiment has been described as a DC power supply. However, the bias power supply in the gas detection apparatus of the present invention is not limited to a DC power supply. The AC power supply can be used. In that case, it is necessary to add a rectifier to the current-voltage conversion circuits 130a to 130b 130c and 130d of the position detection device 115C.

In addition, the position detection device 115C in the tenth embodiment converts the output current from the hydrogen gas detection sensor 125 into a digital signal and performs an arithmetic process, but does not convert the digital signal into an analog signal and calculates the circuit configuration. It is also possible to process.

[0254] As described above, according to the present invention illustrated in the first to tenth embodiments, a distributed hydrogen gas detection sensor can be realized in a semiconductor system. In particular, the hydrogen gas detection sensor that has been one-dimensional (linear) in the hydrogen gas detection area that was previously realized with the optical fiber hydrogen gas detection sensor is realized with the semiconductor gas detection sensor of the present invention. In addition, a gas detection sensor having a two-dimensional (planar) gas detection area can be realized. In the present invention, it is possible to improve the response speed and eliminate the influence of humidity by increasing the temperature of the detection film in the gas detection sensor.

Furthermore, according to the present invention, the gas detection region is one-dimensional using a plurality of minute sensor cells that connect a one-dimensional linear configuration or a two-dimensional planar configuration with only a laminated structure of a detection film and a resistance layer. A gas detection sensor can be configured by arranging in a linear or two-dimensional plane.

Industrial applicability

[0255] According to the present invention, it is possible to easily and accurately detect a hydrogen leak location in hydrogen equipment and piping, and to greatly reduce the time and effort until the discovery of a hydrogen leak location. It is useful because it can greatly contribute to ensuring the safety of hydrogen equipment.

Claims

The scope of the claims

[1] a substantially strip-shaped resistive layer having a predetermined resistance value,

A gas detection sensor comprising a common electrode disposed in contact with at least one surface in a longitudinal direction of the detection film and bonded to the resistance layer via the detection film;

A gas detection sensor configured such that the detection film is linearly exposed along the longitudinal direction.

[2] The resistance layer, the detection film, and the common electrode are stacked and configured such that a space is formed in the uppermost layer so that the detection film is exposed along the longitudinal direction. Item 1. The gas detection sensor according to item 1.

[3] The gas detection sensor according to claim 1, further comprising a strip-like base material having electrical insulation, wherein the resistance layer, the detection film, and the common electrode are provided on the base material.

[4] A substantially strip-shaped base material having electrical insulation is further provided, and the resistance layer, the detection film, and the common electrode are sequentially laminated on the base material, and the topmost common electrode is stacked. The gas detection sensor according to claim 1, wherein an air gap is formed so that the detection film is exposed along a longitudinal direction.

[5] A substantially strip-shaped base material having electrical insulation is further provided, and the common electrode, the detection film, and the resistance layer are stacked in this order on the base material, and the uppermost resistance layer is formed. The gas detection sensor according to claim 1, wherein a void portion is formed so that the detection film is exposed along a longitudinal direction.

[6] A substantially planar resistive layer having a predetermined resistance value,

A sensing film made of a material that is laminated so as to be in contact with one surface of the resistance layer and whose electrical characteristics change by contact with the gas to be sensed; and A gas detection sensor comprising a common electrode, which is laminated with respect to the resistance layer via the detection film and formed of a conductor,

A gas detection sensor configured to expose the detection film in a planar shape.

[7] The laminated structure of the resistance layer, the sensing film, and the common electrode, wherein a space is formed in the uppermost layer so that the sensing film is exposed in a planar shape. Gas detection sensor.

[8] The gas detection according to claim 6, further comprising a substantially planar base material having electrical insulation, wherein the resistance layer, the detection film, and the common electrode are laminated on the base material. Sensor.

[9] It has a detection film made of a material whose electrical characteristics change by contact with the gas to be detected, and the detection surface has a substantially band shape, and when the gas to be detected is detected, the gas detection position Gas detection sensor that divides current according to the output,

A bias power supply for supplying power to the gas detection sensor;

A gas detection device comprising a calculator for calculating a gas detection position by calculating a current-divided signal of the gas detection sensor force;

The computing unit subtracts the signal when the gas detection target gas divided by the gas detection sensor force is not detected and the signal when it is detected, and adds the subtraction result to the calculation result and the division process A gas detection device configured to detect a gas detection position based on the calculated result.

[10] It has a detection film made of a material whose electrical characteristics change by contact with the gas to be detected, and the detection surface is configured to be a substantial surface, and gas detection is performed when the gas to be detected is detected. Gas detection sensor that outputs current divided in four directions according to the position,

A bias power supply for supplying power to the gas detection sensor;

The computing unit subtracts the signal when the gas detection target gas divided by the gas detection sensor force is not detected and the signal when detected, and adds the subtraction result to the calculation result and the subtraction process. A gas detection device configured to detect a gas detection position based on the calculated result. [11] A gas detection device having a gas detection sensor whose resistance changes when a gas to be detected is detected,

A sensing film formed in a substantially belt-like shape,

Each resistance value change between the common electrode and the first electrode and between the common electrode and the second electrode is measured via the resistance layer, and based on the resistance value change, A gas detection device configured to calculate a gas detection position.

[12] A base material that is electrically insulative and formed in a substantially strip shape,

A resistance value change between the common electrode and the first electrode and a resistance value change between the common electrode and the second electrode are measured via the resistance layer, and the resistance value change is determined based on each resistance value change. A gas detection device configured to calculate a gas detection position of the detection film.

[13] A base material that is electrically insulating and formed in a substantially strip shape,

A resistance layer laminated on a longitudinal surface of the sensing film; and

In order to detect a change in resistance of the sensing film, a first layer provided at both ends of the resistance layer. An electrode and a second electrode,

A predetermined bias voltage is applied to the detection film via the common electrode, a resistance value change between the common electrode and the first electrode, and the common electrode and the second electrode via the resistance layer. A gas detection device configured to measure a change in resistance value between and to calculate a gas detection position of the detection film based on each change in resistance value.

[14] The gas to be detected is a gas containing hydrogen, and the detection film adsorbs hydrogen molecules and dissociates them into protons, and an electric resistivity by adsorbing the dissociated protons. With a metal oxide that decreases,

The main component of the catalyst includes either platinum (Pt) or palladium (Pd), and the main component of the metal oxide is tin oxide (SnO), molybdenum trioxide (MnO),

2 3 Tungsten trioxide (WO), titanium dioxide (TiO), iridium hydroxide (Ir (OH) n),

3 2

Gold of either vanadium pentoxide (V O) or rhodium oxide (Rh O · χΗ Ο)

2 5 2 3 2

The gas detection device according to any one of claims 9 to 13, comprising a genus acid salt.

[15] The gas to be detected is a gas containing hydrogen, and the detection film adsorbs hydrogen molecules and dissociates into protons and an electric resistivity by adsorbing the dissociated protons. With a metal oxide that decreases,

3 2

Gold of either vanadium pentoxide (V O) or rhodium oxide (Rh O · χΗ Ο)

2 5 2 3 2

Including a metal oxide,

14. The catalyst according to any one of claims 9 to 13, wherein the catalyst is a fine particle having a particle size of 10 nm or less, and has a structure in which the catalyst is dispersed and supported on the metal oxide fine particle having a particle size of 10 nm to lOO nm. The gas detection device according to any one of the deviations.

16. The gas detection device according to claim 11, wherein the common electrode formed on the detection film has a gap that allows the detection film to be exposed to a gas to be detected.

[17] A gas detection device having a gas detection sensor whose resistance changes when a gas to be detected is detected, A sensing film formed in a substantially belt-like shape,

A resistive layer bonded and stacked on one surface of the detection film in the longitudinal direction, and bonded and stacked on another surface of the detection film in the longitudinal direction, and a predetermined bias voltage is applied to the detection film. A common electrode for applying,

The converting means converts a current value flowing between the common electrode and the first electrode through the resistance layer and a current value flowing between the common electrode and the second electrode into a voltage value. In other words, a gas detection device having an arithmetic unit that calculates a gas detection position based on the converted voltage value.

[18] In a state where the detection film detects the gas to be detected, the current value flowing between the common electrode and the first electrode is II, and the current flows between the common electrode and the second electrode. When the current value is 12 and kl is a constant,

E = kl X I2 / (11 +12)

The gas detection device according to claim 17, wherein the gas detection device is configured to detect a gas detection position on the detection film in accordance with a value E calculated from the above.

[19] In a state where the detection film detects the gas to be detected, the current value flowing between the common electrode and the first electrode is II, and the current flows between the common electrode and the second electrode. When the current value is 12 and k2 is a constant,

E = k2 X I2 / ll

[20] In a state where the detection film detects the gas to be detected, the current value flowing between the common electrode and the first electrode is II, and the current flows between the common electrode and the second electrode. When the current value is 12 and k3 is a constant,

E = k3 X (I2-I1) / (I1 + I2) The gas detection device according to claim 17, wherein the gas detection device is configured to detect a gas detection position on the detection film in accordance with a value E calculated from the above.

[21] The detection film does not detect the gas to be detected! The value of the bias current flowing between the common electrode and the first electrode in the saddle state is lib, and the bias current flowing between the common electrode and the second electrode is I2b.

The current value flowing between the common electrode and the first electrode in a state where the detection film detects the gas to be detected is II, and the current value flowing between the common electrode and the second electrode is 12. , Where k4 is a constant

E = k4 X (12— I2b) / ((II— lib) + (12— I2b))

[22] The detection film does not detect the gas to be detected! The value of the bias current flowing between the common electrode and the first electrode in the saddle state is lib, and the bias current flowing between the common electrode and the second electrode is I2b.

The current value flowing between the common electrode and the first electrode in a state where the detection film detects the gas to be detected is II, and the current value flowing between the common electrode and the second electrode is 12. , Where k5 is a constant

E = k5 X (12—I2b) / (I1—lib)

[23] When the detection film does not detect the gas to be detected, the value of the bias current flowing between the common electrode and the first electrode in the soot state is represented by lib, and the common electrode and the second electrode The bias current flowing between them is I2b,

The current value flowing between the common electrode and the first electrode in a state where the detection film detects the gas to be detected is II, and the current value flowing between the common electrode and the second electrode is 12. , Where k6 is a constant

E = k6 X [{(12— I2b) (II— Ilb)} / {(I1— lib)

+ (12— I2b)}] The gas detection device according to claim 17, wherein the gas detection device is configured to detect a gas detection position on the detection film in accordance with a value E calculated from the above.

24. The gas detection device according to claim 9, further comprising a hole penetrating the first electrode, the detection film, and the resistance layer.

[25] The gas detection device according to any one of [9] to [11], further comprising heating means for heating the temperature of the detection film from 60 ° C to 150 ° C.

[26] A gas detection device having a gas detection sensor that changes resistance when a combustible gas is detected.

A sensing film formed in a substantially belt-like shape,

The temperature of the detection film is heated to 200 ° C. and 400 ° C., and between the common electrode and the first electrode and between the common electrode and the second electrode through the resistance layer. A gas detection device configured to measure each resistance value change and calculate a gas detection position of the detection film based on the resistance value change.

[27] A gas detection device having a gas detection sensor whose resistance changes when a gas to be detected is detected,

A rectangular resistive layer laminated on one side of the sensing film;

A linear first electrode and a second electrode provided on a pair of opposing sides of the resistance layer and extending in the X direction to detect a gas detection position in the X direction; and

Provided on the other pair of opposing sides of the resistance layer to detect the gas detection position in the Y direction. A linear third electrode and a fourth electrode extending in the Y direction,

Gas detector equipped with.

28. The gas detection device according to claim 27, comprising a base material having electrical insulation, wherein the resistance layer, the detection layer, and the common electrode are sequentially stacked on the base material.

29. The gas detection device according to claim 27, further comprising a base material having electrical insulation, wherein the common electrode, the detection film, and the resistance layer are sequentially stacked on the base material.

[30] The gas to be detected is a gas containing hydrogen, and the detection film has a catalyst having an action of adsorbing hydrogen molecules and dissociating into protons, and adsorbing the dissociated protons to reduce the electrical resistivity. And a metal oxide

The main component of the catalyst contains either one of platinum (Pt) or palladium (Pd), and the main component of the metal oxide is tin oxide (SnO), molybdenum trioxide (MnO),

3 2

Either vanadium pentoxide (V O) or rhodium oxide (Rh O · χΗ Ο)

2 5 2 3 2

28. The gas detection device according to claim 27.

31. The gas detection device according to claim 27, wherein the catalyst is a fine particle having a particle size of 10 nm or less and has a structure in which the catalyst is dispersed and supported on the metal oxide fine particle having a particle size of 10 nm to lOO nm.

32. The gas detection device according to claim 27, wherein the common electrode formed on the detection film has a gap for exposing the detection film to a gas to be detected.

[33] A change in resistance value between the common electrode and the first electrode and between the common electrode and the second electrode is detected and based on the change in resistance value! X direction conversion means that calculates the X direction position of the gas detection position;

A change in resistance value between the common electrode and the third electrode and between the common electrode and the fourth electrode is detected, and based on the change in resistance value, a gas detection position in the Y direction is detected. Y direction conversion means for calculating

The X direction conversion means and the Y direction conversion means convert the current value of each electrode from the first electrode to the fourth electrode into a voltage value, and based on the converted voltage value! 28. The gas detection device according to claim 27, further comprising an arithmetic unit that calculates the gas detection position. [34] Ia is a current value flowing between the common electrode and the first electrode in a state where a gas to be detected is detected, and Ib is a current value flowing between the common electrode and the second electrode. When the current value flowing between the common electrode and the third electrode is Ic, the current value flowing between the common electrode and the fourth electrode is Id, and k7 and k8 are constants. This

EX = k7 X Ib / (Ia + Ib)

The gas detection position in the X direction on the detection film is detected according to the value EX calculated by

EY = k8 X Id / (Ic + Id)

34. The gas detection device according to claim 33, configured to detect a gas detection position in the Y direction on the detection film in accordance with a value EY calculated from the above.

[35] The current value flowing between the common electrode and the first electrode in a state where the gas to be detected is detected is Ia, the current value flowing between the common electrode and the second electrode is Ib, When the current value flowing between the common electrode and the third electrode is Ic, the current value flowing between the common electrode and the fourth electrode is Id, and k9 and klO are constants. ,

EX = k9 X Ib / la

The gas detection position in the X direction on the detection film is detected according to the value EX calculated from EY = klO X Id / lc

[36] Ia is a current value flowing between the common electrode and the first electrode in a state where a gas to be detected is detected, and Ib is a current value flowing between the common electrode and the second electrode. When the current value flowing between the common electrode and the third electrode is Ic, the current value flowing between the common electrode and the fourth electrode is Id, and kl l and kl2 are constants In addition,

EX = kl l X (Ib-Ia) / (Ia + Ib)

The gas detection position in the X direction on the detection film is detected according to the value EX calculated from EY = kl2 X (Id— Ic) / (Ic + Id)

34. The gas detection device according to claim 33, configured to detect a gas detection position in the X direction on the detection film in accordance with a value EY calculated from the above.

[37] The detection film detects the gas to be detected! / Cunning! The common electrode and the first electrode in the saddle state The bias current flowing between the common electrode and the second electrode is defined as lab, the bias current flowing between the common electrode and the second electrode is defined as Ibb, and the bias current flowing between the common electrode and the third electrode is defined as Icb, and bias current flowing between the common electrode and the fourth electrode is Idb,

The current value flowing between the common electrode and the first electrode when the detection film detects the gas to be detected is la, and the current value flowing between the common electrode and the second electrode is lb. The current value flowing between the common electrode and the third electrode is Ic, the current value flowing between the common electrode and the fourth electrode is Id, and kl3 and kl4 are constants. sometimes,

EX = kl3 X (lb -Ibb) / {(la -lab) + (lb -Ibb)}

EY = kl4 X (ld-Idb) / {(lc-Icb) + (Id -Idb)}

A bias current flowing between the common electrode and the first electrode when the detection film detects a gas to be detected and is in a distorted state is defined as lab, and flows between the common electrode and the second electrode. The bias current is Ibb, the bias current flowing between the common electrode and the third electrode is Icb, the bias current flowing between the common electrode and the fourth electrode is Idb,

When the detection film detects the gas to be detected, the current value flowing between the common electrode and the first electrode is la, and the current value flowing between the common electrode and the second electrode is lb The current value flowing between the common electrode and the third electrode is Ic, the current value flowing between the common electrode and the fourth electrode is Id, and kl5 and kl6 are constants. sometimes,

EX = kl5 X (lb— Ibb) Z (la— lab)

EY = kl6 X (ld-Idb) / (lc-Icb)

The gas detection position in the Y direction on the detection film is detected according to the value EY calculated from 34. The gas detection device according to claim 33 configured.

[39] The detection film detects the gas to be detected! / Cunning! The bias current flowing between the common electrode and the first electrode in the saddle state is lab, the bias current flowing between the common electrode and the second electrode is Ibb, and the common electrode and the third electrode A bias current flowing between the common electrode and the fourth electrode is Icb, and a bias current flowing between the common electrode and the fourth electrode is Idb.

When the detection film detects the gas to be detected, the current value flowing between the common electrode and the first electrode is la, and the current value flowing between the common electrode and the second electrode is lb The current value flowing between the common electrode and the third electrode is Ic, the current value flowing between the common electrode and the fourth electrode is Id, and kl8 and kl9 are constants. sometimes,

EX = kl7 X {(lb-Ibb) (la-Iab)} / {(la -lab)

+ (lb -Ibb)}

The gas detection position in the X direction on the detection film is detected according to the value EX calculated from EY = kl8 X {(Id— Idb) — (Ic— Icb)} / {(Ic— Icb)

+ (Id -Idb)}

40. The gas detection device according to claim 27, further comprising a hole penetrating the common electrode, the detection film, and the resistance layer.

[41] The heating means for heating the temperature of the detection film from 60 ° C to 150 ° C.

27. The gas detection device according to 27.

[42] A gas detection device having a gas detection sensor whose resistance changes when a combustible gas is detected,

A rectangular resistive layer laminated on one side of the sensing film;

It is formed in contact with the other surface of the detection film and applies a predetermined bias voltage to the detection film. Common electrode to be applied,

Heating means for heating the temperature of the detection film to a temperature of 200 ° C and 400 ° C;

Gas detector equipped with.

[43] A gas detection device having a gas detection sensor whose electrical resistance changes when a gas to be detected is detected,

A bias voltage is applied to the common electrode, a resistance value change between the common electrode and the detection electrode is detected, and a gas detection position is calculated based on the position of the sensor cell where the resistance value change is detected. The gas detector configured as described above.

44. The gas detection device according to claim 43, wherein the base material has holes penetrating the base material at predetermined intervals.

[45] A gas detection device having a gas detection sensor having a detection film whose electrical resistance changes when a gas to be detected comes into contact with the gas,

A substrate formed by a material having electrical insulation properties into a substantial band shape and penetrated by a plurality of holes arranged linearly at predetermined intervals;

Each sensing film is formed on the other surface of the base material in a pair with the common electrode. A plurality of detection electrodes formed on the other end of the unit,

A bias voltage is applied to the common electrode, a change in resistance value between the common electrode and the detection electrode of the sensor cell is detected, and a gas detection position is calculated based on the position of the sensor cell where the change in resistance value is detected. A gas detector configured to do.

[46] The gas detection position is calculated based on a resistance value change between the common electrode and the detection electrode by connecting the detection electrodes with a resistor having a predetermined resistance value.

The gas detection device according to claim 43 or 45.

[47] A gas detection device having a gas detection sensor having a detection film whose electrical resistance changes when a gas to be detected is detected,

A base material that is formed in a substantially rectangular shape by an electrically insulating material, and is penetrated by a plurality of holes arranged at lattice-shaped intersections at a predetermined pitch;

A noise voltage is supplied to the sensor cell through the Xi electrode at a predetermined time interval, a change in resistance value between the Xi electrode and the Yj electrode to which the bias voltage is supplied is detected, and the resistance value change is detected. A gas detection device configured to calculate a gas detection position based on a position of a sensor cell in which gas is detected.

48. The gas detection device according to claim 47, wherein the gas detection position is calculated by detecting a row number and a column number of the detection electrode.

[49] The common detection electrodes in the row direction and the common detection electrodes in the column direction are connected by a resistor having a predetermined resistance value, and detection of both ends of the common detection electrodes in the row direction and the column direction of the sensor cell is performed. 48. The gas detection device according to claim 47, configured to calculate a gas detection position based on a change in the resistance value of the film. [50] The gas to be detected is a gas containing hydrogen, and the detection film of the sensor cell has a catalyst having an action of adsorbing hydrogen molecules and dissociating into protons, and an electric resistivity by adsorbing the dissociated protons. A metal oxide that decreases,

3 2

Gold, either vanadium pentoxide (V O) or rhodium oxide (Rh O · χΗ Ο)

2 5 2 3 2

44. The gas detection device according to claim 43, comprising a metal oxide.

51. The gas detection device according to claim 50, wherein the catalyst is a fine particle having a particle diameter of 10 nm or less and has a structure in which the catalyst is dispersed and supported on the metal oxide fine particle having a particle diameter of 10 nm to lOO nm.