KR102640660B1 - Gas sensor device - Google Patents

Abstract

In a gas measuring device that improves the measurement inaccuracy of an electrochemical gas sensor due to changes in humidity, an electrochemical gas sensor that generates a current through a redox reaction with a specific gas in the air and measures the concentration of the specific gas, humidity It includes a humidity sensor that detects a change, a compensation unit that compensates for the measured value of the electrochemical gas sensor based on the humidity change measured by the humidity sensor, and the humidity sensor is the same as the humidity change condition inside the electrochemical gas sensor. A gas measuring device, characterized in that provided in the gas measuring device under the following conditions.

Description

Gas measuring device {GAS SENSOR DEVICE}

The present invention relates to a gas measuring device, and can be specifically applied to the field of technology that improves the inaccuracy of an electrochemical gas sensor by compensating for disturbance due to changes in atmospheric humidity in the measured values of the electrochemical gas sensor.

There are many types of dangerous gases in our living environment, and recently, there have been a series of gas leaks in homes, businesses, and factories, as well as explosion accidents and pollution in oil complexes, coal mines, and chemical plants.

Human sense organs are hardly able to quantify the concentration or determine the type of dangerous gas. In order to respond to this, gas sensors that utilize the physical and chemical properties of materials have been developed and are used to detect gas leaks, measure and record concentration, and provide alarms.

An electrochemical gas sensor can be used as a gas sensor. An electrochemical gas sensor can detect gas by measuring the electromotive force generated between the counter electrode and the counter electrode where the redox reaction occurs.

Electrochemical gas sensors can react sensitively to changes in atmospheric humidity, and in order to improve accuracy, it is necessary to compensate for the measured values of electrochemical gas sensors by taking humidity into account.

However, due to the structural characteristics of the electrochemical gas sensor, the humidity change that affects the measured value of the electrochemical gas sensor may differ from the humidity change recognized by the humidity sensor.

Accordingly, there is a need to improve the inaccuracy of the electrochemical gas sensor by making the humidity change that affects the measured value of the electrochemical gas sensor the same as the humidity change recognized by the humidity sensor and accurately compensate for the humidity change in the measured value of the electrochemical gas sensor. there is.

The present invention aims to solve the above-described problems and other problems through the specification of the present invention.

The present invention seeks to provide a solution for obtaining accurate measured values by compensating for the effect of humidity changes on the measured values of an electrochemical gas sensor.

The present invention aims to provide a solution that improves accuracy by compensating for humidity changes in the measured values of an electrochemical gas sensor by making the humidity changes that affect the measured values of an electrochemical gas sensor equal to the humidity changes perceived by the humidity sensor. do.

The present invention seeks to provide a solution that improves accuracy in compensation for humidity changes by reducing humidity changes that affect the measured values of an electrochemical gas sensor.

According to an embodiment of the present invention to achieve the above object, an electrochemical gas sensor that generates a current through a redox reaction with a specific gas in the air to measure the concentration of the specific gas, a humidity sensor that detects changes in humidity, and a compensation unit that compensates for the measured value of the electrochemical gas sensor based on the humidity change measured by the humidity sensor, wherein the humidity sensor detects the same humidity change as the humidity change occurring inside the electrochemical gas sensor. A gas measuring device is provided, characterized in that it is provided in a gas measuring device.

In addition, according to an embodiment of the present invention for achieving the above object, the electrochemical gas sensor includes a first housing that includes a first hole through which air flows into one side and forms an external shape of the electrochemical gas sensor. And, the humidity sensor provides a gas measuring device, wherein the humidity sensor is included in a second housing that includes a second hole through which air flows in on one side and forms a receiving space.

In addition, according to an embodiment of the present invention for achieving the above object, the size of the second hole is formed in response to a change in humidity inside the first housing through the first hole. to provide.

In addition, according to an embodiment of the present invention for achieving the above object, the first housing seals the first hole and further includes a first diffusion barrier that diffuses and transmits air introduced through the first hole. and the second housing seals the second hole and further includes a second diffusion barrier that diffuses and transmits air introduced through the second hole.

In addition, according to one embodiment of the present invention for achieving the above object, the second diffusion barrier has thickness, hole size, and hole per unit volume in response to changes in humidity inside the first housing through the first diffusion barrier. It provides a gas measuring device characterized in that it forms a number of.

In addition, according to an embodiment of the present invention for achieving the above object, the gas measuring device includes the electrochemical gas sensor and the humidity sensor, and further includes a third housing including a third hole through which air flows. It provides a gas measuring device comprising:

In addition, according to an embodiment of the present invention for achieving the above object, the third housing seals the third hole and includes a third diffusion barrier that diffuses and transmits air introduced through the third hole. Provided is a gas measuring device characterized in that.

In addition, according to an embodiment of the present invention for achieving the above object, the third housing is a gas measurement characterized in that it includes a humidity buffer that reversibly absorbs or releases water molecules introduced through the third hole. Provides a device.

In addition, according to an embodiment of the present invention for achieving the above object, a gas measuring device is provided, wherein the humidity buffering agent is applied to at least one side of the third housing.

In addition, according to an embodiment of the present invention for achieving the above object, in the gas measuring device, an electrochemical gas sensor that generates a current through a redox reaction with a specific gas in the air to measure the concentration of the specific gas; A fourth housing including the electrochemical gas sensor and a fourth hole through which air flows, a humidity buffer provided inside the fourth housing and reversibly absorbing or releasing water molecules flowing in through the fourth hole. It provides a gas measuring device comprising:

In addition, according to an embodiment of the present invention for achieving the above object, a gas measuring device is provided, wherein the humidity buffering agent is applied to at least one side of the fourth housing.

The effects of the electrochemical gas sensor according to the present invention will be described as follows.

The present invention can improve the accuracy of an electrochemical gas sensor by compensating for the effect of changes in atmospheric humidity on the measured values of the electrochemical gas sensor.

The present invention removes the humidity change that affects the measured value of the electrochemical gas sensor and the deviation of the humidity change recognized by the humidity sensor, thereby improving the accuracy when compensating for the humidity change in the measured value of the electrochemical gas sensor. .

The present invention reduces humidity changes that affect the measured values of an electrochemical gas sensor, and can improve accuracy when compensating for changes in humidity in the measured values of an electrochemical gas sensor.

Further scope of applicability of the present invention will become apparent from the detailed description that follows. However, since various changes and modifications within the spirit and scope of the present invention can be clearly understood by those skilled in the art, the detailed description and specific embodiments such as preferred embodiments of the present invention are understood to be given only as examples. It has to be.

Figure 1 is a cross-sectional view to explain the basic structure and operating principle of an electrochemical gas sensor.
Figure 2 is a graph to explain the variation in measured values due to changes in humidity depending on the type of electrolyte and sensor structure in an electrochemical gas sensor.
Figure 3 is a graph to explain the change in the measured value of the electrochemical gas sensor when air is introduced through the hole in the case after casing the electrochemical gas sensor.
Figure 4 is a graph to explain the change in measured values when air is introduced through a diffusion barrier after casing an electrochemical gas sensor.
Figure 5 is a block diagram of the main components of a gas measuring device according to an embodiment of the present invention.
Figure 6 is a conceptual diagram to explain the factors that cause errors in the measured values of an electrochemical gas sensor despite compensation for humidity changes in existing gas measurement devices.
Figure 7 is a conceptual diagram for explaining a gas measuring device according to an embodiment of the present invention.
Figure 8 is a conceptual diagram for explaining a gas measuring device according to another embodiment of the present invention.
Figure 9 is a conceptual diagram for explaining a gas measuring device according to another embodiment of the present invention.
Figure 10 is a conceptual diagram for explaining a gas measuring device according to another embodiment of the present invention.
Figure 11 is a diagram to explain that the rate of change in internal humidity of an electrochemical gas sensor varies depending on conditions.
Figure 12 is a diagram to explain that the magnitude of change in internal humidity of an electrochemical gas sensor varies depending on conditions.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. However, identical or similar components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted. The suffixes “module” and “part” for components used in the following description are given or used interchangeably only for the ease of preparing the specification, and do not have distinct meanings or roles in themselves. Additionally, in describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed descriptions will be omitted. In addition, the attached drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings, and all changes included in the spirit and technical scope of the present invention are not limited. , should be understood to include equivalents or substitutes.

Terms containing ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Figure 1 is a cross-sectional view to explain the basic structure and operating principle of an electrochemical gas sensor.

An electrochemical gas sensor is a sensor that detects changes in current value caused by the redox reaction of the anode and cathode within the electrolyte.

Electrochemical gas sensors may consist of three electrodes or two electrodes. However, a two-electrode electrochemical gas sensor has an electrode that measures current and an electrode that measures voltage, so as the current flows, a difference occurs between the potential applied by the power source and the potential at the electrode, so the voltage-current curve may not appear correctly. there is. Therefore, in order to trust the two-electrode electrochemical gas sensor, limiting requirements such as electrolyte storage must be as small as possible and the voltage drop value must be small due to low flowing current. However, because it is difficult to meet these limitations, a three-electrode electrochemical gas sensor is mainly used, and Figure 1 shows an example of an electrochemical gas sensor consisting of three electrodes.

Looking at the operating principle of the electrochemical gas sensor through Figure 1, it is as follows.

The three electrodes in Figure 1 include a working electrode where an oxidation (reduction) reaction occurs, a counter electrode where a reduction (oxidation) reaction occurs at the same time, and a potential that changes with the redox reaction and detects the potential. It consists of a reference electrode to keep it constant.

Carbon monoxide (CO) flowing into the electrochemical gas sensor is oxidized at the detection electrode (working electrode) to generate hydrogen ions and electrons. Hydrogen ions pass through an electrolyte provided between the working electrode and the counter electrode and are reduced at the working electrode. At this time, a potential difference occurs between the working electrode and the reference electrode, and accordingly, electrons generated from the working electrode move to the counter electrode along the lead wire (not shown).

The reference electrode is a reference electrode for measuring the exact voltage at the working electrode. It measures the potential with the working electrode. The resistance of the voltmeter is very large, so the current is It doesn't flow. Electrochemical gas sensors can measure the concentration of carbon monoxide (CO) by measuring the current flowing between the working electrode and the counter electrode.

In addition to the electrodes described above, the electrochemical gas sensor may include an electrolyte between the working electrode and the counter electrode, and the electrolyte is used to diffuse the gas introduced into the electrochemical gas sensor. It can be supported by a permeable porous membrane.

In addition, the electrochemical gas sensor is provided in a housing that forms the outer shape, and atmospheric gas can flow in through the hole provided in the housing, and the hole provided in the housing can be sealed with a capillary diffusion barrier. You can.

A capillary diffusion barrier is a membrane that controls the diffusion of gases flowing into an electrochemical gas sensor, and allows gas to move from the outside to the inside through Knudesn diffusion. Capillary diffusion barrier is related to the spectrum of gas changes that can be detected by electrochemical gas sensors.

However, the capillary diffusion barrier also affects the concentration or number of water molecules in the penetrating air, so it may affect the measured value of the electrochemical gas sensor due to changes in moisture.

Specifically, the concentration or number of water molecules in the air passing through the capillary diffusion barrier may decrease according to Fick's law.

Fick's law can be expressed as follows:

In Fick's law, J is the diffusion flux of water molecules, D is the diffusion coefficient, and C is the analyte concentration at a given point in space. dC/dx refers to the slope of analyte concentration in the x direction.

The capillary diffusion barrier determines the diffusion constant, and a difference in concentration of fire molecules can occur across the diffusion barrier.

Below, we will look at changes in measured values of an electrochemical gas sensor due to changes in moisture, and examine the structure of the present invention that prevents changes in measured values of an electrochemical gas sensor due to changes in moisture.

Figure 2 is a graph to explain the change in measured values due to changes in humidity depending on the type of electrolyte and sensor structure in an electrochemical gas sensor.

Measured values from electrochemical gas sensors may include disturbance caused by moisture in the atmosphere.

More specifically, changes may occur in the measured values of the electrochemical gas sensor in areas where moisture in the atmosphere changes.

Through Figure 2, the change in measured value of the electrochemical gas sensor according to moisture change is as follows.

Electrochemical gas sensors may have different measured values depending on the type of electrolyte and the structure of the sensor. Figure 2 includes four sensor examples with different measured values depending on the type of electrolyte and the structure of the sensor. However, the measured values of each sensor include common changes depending on changes in humidity.

Specifically, the measured value of the electrochemical gas sensor varies proportionally between the measured value and the humidity change in the humidity change section and regresses geometrically. However, the measured value of the electrochemical gas sensor is not affected by the level of humidity in a certain humidity range. In other words, the measured value of an electrochemical gas sensor contains characteristics that vary depending on changes in humidity.

Changes in the measured values of electrochemical gas sensors due to changes in humidity can provide incorrect information in various industrial fields or general life that use electrochemical gas sensors. Therefore, it is necessary to correct errors due to changes in humidity in the measured values of the electrochemical gas sensor.

Errors due to changes in humidity in the measured values of an electrochemical gas sensor can be controlled through the method of casing the electrochemical gas sensor or the presence or location of a diffusion barrier, which will be discussed in detail below.

Figure 3 is a graph to explain the change in measured value of the electrochemical gas sensor when air is introduced through the hole in the case after casing the electrochemical gas sensor, and Figure 4 is a graph showing the change in measured value of the electrochemical gas sensor after casing the electrochemical gas sensor. This is a graph to explain the change in measured values when air is introduced through a barrier.

Because electrochemical gas sensors are sensitive to humidity changes, speed, and size, if the module is cased, the speed and size of humidity changes inside the electrochemical sensor may be reduced. This is because the electrochemical gas sensor does not respond to the level of humidity, but to changes in humidity.

Looking at the graph of FIG. 3, it can be seen that the fluctuation range of the measured value of the electrochemical gas sensor without a casing is greater than that of the case with a casing.

The housing casing the electrochemical gas sensor may include a hole through which gas can flow, and the change in humidity inside the housing through the hole occurs at a smaller width around the average value than the change in humidity outside the housing, causing the electrochemical gas Disturbance caused by changes in humidity can be reduced in the sensor's measured values.

In other words, a housing including a hole can reduce changes in humidity diffusing from the outside to the inside through the hole.

Additionally, the diffusion barrier that seals the hole in the casing and controls gas diffusion can greatly reduce the variation in measured values of an electrochemical gas sensor due to changes in humidity.

Looking at the graph in FIG. 4, when the casing is placed through the housing and the hole provided in the housing is sealed with a diffusion barrier, the measurement value of the electrochemical gas sensor fluctuates to a greater extent than that of the electrochemical gas sensor without the casing. You can see that the width is decreasing.

Additionally, changes in internal and external humidity based on the diffusion barrier may cause a time delay. This may mean that when the humidity change is measured through a humidity sensor outside the diffusion barrier, an error occurs due to the time delay between the humidity change affecting the electrochemical gas sensor and the humidity change measured by the humidity sensor. In this regard, the gas measuring device of the present invention will be described and examined in detail.

In other words, the degree to which humidity changes affect the measured values of an electrochemical gas sensor may vary depending on the presence or absence of a housing that casing the electrochemical gas sensor and through which gas flows through a hole, and the presence or absence of a diffusion barrier that seals the hole. . Therefore, in order to compensate for fluctuations in the measured values of the electrochemical gas sensor due to changes in humidity, it is necessary to provide a humidity sensor based on the above information.

Below, we will look at a gas measuring device according to an embodiment of the present invention.

Figure 5 is a block diagram of the main components of a gas measuring device according to an embodiment of the present invention.

The gas measuring device of the present invention may include an electrochemical gas sensor 200, a humidity sensor 300, and a compensation unit 400 to compensate for measurement value disturbance caused by changes in humidity.

The electrochemical gas sensor 200 of the present invention is no different from the basic electrochemical gas sensor 200 described in FIG. 1. However, since the main feature of the present invention is to compensate for changes in values measured by the sensor due to changes in humidity, the type of gas sensor does not need to be limited to electrochemical gas sensors. In other words, any type of sensor that changes the value measured by a gas sensor due to changes in humidity can be used.

The humidity sensor 300 is a device for measuring changes in humidity that affect the electrochemical gas sensor 200. As seen in FIGS. 3 and 4, the electrochemical gas sensor 200 may have different humidity changes between the inside and outside depending on the presence or absence of a housing or a diffusion barrier. Therefore, the humidity sensor 300 needs to be provided in the gas measuring device under the same conditions as the humidity change conditions inside the electrochemical gas sensor 200. However, the humidity sensor 300 may be omitted in some cases, which will be examined in detail with reference to FIG. 10.

The compensation unit 400 is a component that compensates for the measured value of the electrochemical gas sensor 200 based on the change in humidity detected by the humidity sensor 300. However, the compensation unit 400 may be omitted in some cases, which will be discussed in detail with reference to FIG. 10.

In addition, the gas measuring device according to the present invention includes a display unit that outputs the measured value compensated by the compensation unit 400, an interface unit or communication unit that transmits the measured value to another external device or server, a power supply unit that supplies power, and a compensated It may further include at least one of a comparator that compares whether the measured value is greater than or equal to a preset value, an audio device that provides an alarm, etc. according to the progress of the comparator, and a control unit that is connected to the component and controls the component.

The display unit displays (outputs) information processed by the gas measurement device. For example, the display unit may display execution screen information of an application running on the gas measuring device, or UI (User Interface) and GUI (Graphic User Interface) information according to the execution screen information.

The display unit includes a liquid crystal display (LCD), a thin film transistor-liquid crystal display (TFT LCD), an organic light-emitting diode (OLED), and a flexible display (3). It may include at least one of a 3D display and an e-ink display.

The interface part becomes a passage through which the gas measuring device can be connected to external devices. For example, the interface unit includes connection terminals for connection with other devices (e.g., earphones, external speakers), ports for short-distance communication (e.g., infrared port (IrDA Port), Bluetooth port, wireless LAN port (Wireless LAN Port, etc.)], or at least one of a power supply terminal for supplying power to a gas measuring device. This interface unit may be implemented in the form of a socket that accommodates an external card such as a Subscriber Identification Module (SIM), a User Identity Module (UIM), or a memory card for information storage.

The power supply unit may be built into the gas measuring device or may include a battery that is removable from the outside of the gas measuring device. The battery may be configured to receive power through a power cable connected to the interface unit.

The control unit can provide or process appropriate information or functions to the user by processing signals, data, information, etc. input or output through the components discussed above, or by running an application program stored in memory. Depending on the case, the control unit may be a component including the comparison unit and the compensation unit 400.

Figure 6 is a conceptual diagram to explain the factors that cause errors in the measured values of an electrochemical gas sensor despite compensation for humidity changes in existing gas measurement devices.

6 shows that an electrochemical gas sensor 200 and a humidity sensor 300 are provided spaced apart from each other on a substrate 500, and the electrochemical gas sensor 200 is provided in a first housing 211 that casing the electrochemical gas sensor 200. ) and a first diffusion barrier 211 that is provided in the first housing and seals the hole through which gas flows into the first housing 210, in which the humidity sensor 300 and the space for detecting changes in humidity are separated. An example is shown.

As explained in FIGS. 3 and 4, the humidity change (b) detected inside the first housing 210 with or without the first housing 210 and the first diffusion barrier 211 casing the electrochemical gas sensor 200 ) may be different from the humidity change (a) detected from the outside of the first housing 211.

Specifically, the width of the humidity change detected by the humidity sensor 300 may be greater than the width of the humidity change that affects the measurement value measured by the electrochemical gas sensor 200 inside the first housing 211.

Additionally, the speed of humidity change detected by the humidity sensor 300 may be greater than the speed of humidity change that affects the measurement value measured by the electrochemical gas sensor 200 inside the first housing 211.

In addition, the humidity change detected by the humidity sensor 300 may have a time delay and a humidity change that affects the measurement value measured by the electrochemical gas sensor 200 inside the first housing 211.

Therefore, in the structure of FIG. 6, when the measured value of the electrochemical gas sensor 200 is corrected based on the humidity change data measured by the humidity sensor 300, the correction value may be inaccurate.

Accordingly, the present invention generates a current through a redox reaction with a specific gas in the air in order to accurately compensate for the measured value of the electrochemical gas sensor 200 based on the humidity change data measured by the humidity sensor 300. An electrochemical gas sensor 200 that measures the concentration of a specific gas, a humidity sensor 300 that detects a change in humidity, and measurement of the electrochemical gas sensor 200 based on the change in humidity measured by the humidity sensor 300. It provides a gas measuring device that includes a compensation unit that compensates for the value, and the humidity sensor 300 is provided in the gas measuring device 300 under the same conditions as the humidity change conditions inside the electrochemical gas sensor 300. .

Figure 7 is a conceptual diagram for explaining a gas measuring device according to an embodiment of the present invention.

7 shows that an electrochemical gas sensor 200 and a humidity sensor 300 are provided spaced apart on a substrate 500 as shown in FIG. 6, and the electrochemical gas sensor 200 is a material that casing the electrochemical gas sensor 200. 1 A space for detecting the humidity sensor 300 and changes in humidity is created by the housing 211 and the first diffusion barrier 211 that is provided in the first housing and seals the hole through which gas flows into the first housing 210. Distinct embodiments are shown.

However, in the embodiment according to the present invention in FIG. 7, in order to ensure that the humidity change detected by the humidity sensor 300 is the same as the humidity change inside the electrochemical gas sensor 200, the gas measuring device according to the present invention includes a humidity sensor. (300) may include a separate housing that casing the electrochemical gas sensor (200).

Specifically, the electrochemical gas sensor 200 includes a first housing on one side through which air flows, a first housing 210 that forms the external shape of the electrochemical gas sensor 200, and the humidity sensor 300 It may include a second hole on one side through which air flows, and may be included in a second housing forming an accommodation space.

That is, in response to the first housing 210 casing the electrochemical gas sensor 200, the humidity sensor 300 is provided inside the second housing 310 casing the temperature sensor, and the electrochemical gas sensor 200 and the humidity sensor 300 can detect changes in humidity through holes provided in the housing casing each.

As seen in FIG. 3, this is to reflect that the measured value of the electrochemical gas sensor 200 changes in response to changes in humidity depending on the presence or absence of a housing casing the electrochemical gas sensor 200.

Specifically, the size of the second hole may be formed in response to a change in humidity inside the first housing 210 through the first hole.

In practice, moisture changes that affect the measured value of the electrochemical gas sensor 200 may depend on the size of the first hole provided in the first housing 210, and the size of the second hole may depend on the size of the first hole. Correspondingly, it may be of a size that can compensate for the same moisture change.

For example, the size of the second hole relative to the internal volume of the second housing 310 may be determined in response to the size of the first hole relative to the internal volume of the first housing 210. Alternatively, the size of the second hole compared to the empty space inside the second housing 310 may be determined in response to the size of the first hole compared to the empty space inside the first housing 210.

In addition, the first housing 210 seals the first hole and further includes a first diffusion barrier 211 that diffuses and transmits air introduced through the first hole, and correspondingly, the second housing 310 is It may include a second diffusion barrier 311 that seals the second hole and diffuses and transmits air introduced through the second hole.

As explained in FIG. 4, the diffusion barrier can control the number of water molecules flowing into the inside, and a delay may occur in humidity changes that affect the measured value of the electrochemical gas sensor 200.

Therefore, the humidity sensor 300 is cased in the same way as the electrochemical gas sensor 200 and includes a separate diffusion barrier to detect the same humidity change as the humidity change occurring inside the electrochemical gas sensor 200. It may be provided in a gas measuring device.

At this time, the second diffusion barrier 311 does not need to be made of the same material as the first diffusion barrier 311.

The second diffusion barrier 311 may form a thickness, hole size, and number of holes per unit volume in response to changes in humidity inside the first housing 210 through the first diffusion barrier 211.

If the second diffusion barrier 311 is formed of the same material as the first diffusion barrier 211, the size and number per unit volume of the plurality of holes provided in the diffusion barrier may be the same. In this case, the thickness of the second diffusion barrier 311 may be a parameter corresponding to the change in humidity inside the first housing 210. Specifically, the first expansion barrier 211 compared to the internal volume of the first housing 210 The thickness of the second expansion barrier 311 relative to the internal volume of the second housing 310 may be determined in response to the thickness of . Alternatively, the thickness of the second diffusion barrier 311 relative to the empty space within the second housing 310 may be determined in response to the thickness of the first expansion barrier 211 relative to the empty space within the first housing 210 .

However, if the material of the second diffusion barrier 311 is different from the material of the first diffusion barrier 211, there may be two or more parameters corresponding to changes in internal humidity of the first housing 210. Moreover, the size of the first hole and the size of the second hole may also be separate parameters.

As a result, the gas measuring device according to the present invention has the size of the hole in the second housing 310 and the second diffusion barrier ( 311) can be optionally provided with a material and thickness, which may be a factor corresponding to the diffusion constant of Fick's law described in FIG. 1.

Figure 8 is a conceptual diagram for explaining a gas measuring device according to another embodiment of the present invention.

8 shows that an electrochemical gas sensor 200 and a humidity sensor 300 are provided spaced apart on a substrate 500, and the electrochemical gas sensor 200 is provided in a first housing 211 that casing the electrochemical gas sensor 200. ) and can detect gas flowing in through the first hole provided in the first housing 211.

In addition, the gas measuring device of FIG. 8 provides a space in which the electrochemical gas sensor 200 and the humidity sensor 300 are accommodated, and may further include a third housing 220 including a third hole through which air flows. You can.

That is, if the humidity sensor 300 and the electrochemical gas sensor 200 are cased in the same housing, the humidity sensor 300 can equally reflect the change in humidity caused by the housing of the electrochemical gas sensor 200.

The third housing 220 seals the third hole and may include a third diffusion barrier 221 that diffuses and transmits air introduced through the third hole.

The electrochemical gas sensor 200 may be additionally cased by the first housing 210, but the difference between the humidity change perceived by the humidity sensor 300 and the humidity change affecting the electrochemical gas sensor 200 may be insignificant. You can.

This is because the degree of humidity change (b) has been reduced to some extent through the third diffusion barrier 221.

That is, the humidity change (b) reduced through the third diffusion barrier 221 can sequentially reduce the humidity change (b') acting on the humidity sensor 300 and the electrochemical gas sensor 200. Additionally, the reduction in measured value disturbance due to changes in humidity through the diffusion barrier may be greater than the reduction through the housing.

Therefore, even if the electrochemical gas sensor 200 includes a separate first housing 210 and does not have a housing for casing the humidity sensor 300, the humidity sensor 300 is inside the first housing 210. It can fully reflect changes in humidity that occur.

In the above, we looked at structural features that equally adjust the humidity change perceived by the humidity sensor 300 and the humidity change occurring inside the electrochemical gas sensor 200 through the housing and diffusion barrier.

Below, we will look at a structure in which errors are reduced even when the measured value of the electrochemical gas sensor 200 is corrected with humidity change data sensed by the humidity sensor using a humidity buffer.

Figure 9 is a conceptual diagram for explaining a gas measuring device according to another embodiment of the present invention.

The present invention may include an electrochemical gas sensor 200, a humidity sensor 300, a third housing 220 casing the electrochemical gas sensor 200 and the humidity sensor 300, and a humidity buffer 222. .

The electrochemical gas sensor 200 and the humidity sensor 300 may be provided spaced apart on the same substrate 500, and the electrochemical gas sensor 200 is cased by a separate first housing 210, and the first It seals the first hole of the housing 210 and may include a first diffusion barrier 211 that diffuses and transmits air introduced through the first hole.

The humidity buffer 222 can reversibly absorb or release water molecules (a) introduced through the third hole of the third housing 220, and any material including inorganic, organic, and polymer can be used.

The humidity buffer 222 may be provided by being applied to at least one side of the third housing 220.

The humidity buffer 222 is configured to reversibly absorb and release the water molecules (a) introduced through the third hole of the third housing 220, rather than irreversibly, and serves to buffer changes in humidity. can do.

As seen in FIG. 2, the electrochemical gas sensor 200 is not affected by the size of humidity but by changes in humidity. If the range of humidity change is reduced, the effect on the measured value of the electrochemical gas sensor 200 can be reduced.

Therefore, even if the electrochemical gas sensor 200 is separated from the humidity sensor 300 by the first housing 210 and the first diffusion barrier 211, the decrease in the humidity change width due to the humidity buffer 222 is due to the humidity Even if the measured value of the electrochemical gas sensor 200 is corrected based on the change in humidity recognized by the sensor 300, the resulting error can be reduced to a negligible level.

In FIG. 8, the electrochemical gas sensor 200 is cased by the first housing 210, whereas the humidity sensor 300 does not include a separate housing, but changes the humidity through the third diffusion barrier 221. This is reduced, so that even if the measured value of the electrochemical gas sensor 200 is corrected based on the change in humidity recognized by the humidity sensor 300, the error in the measured value can be ignored.

9 shows an embodiment including the first diffusion barrier 211 in the first housing 210, but in some cases, both the first housing 210 and the first diffusion barrier 211 may be absent. , it may be considered that the first diffusion barrier 211 does not exist, or that it includes a third diffusion barrier that seals the third hole of the third housing 220 and diffuses and transmits air introduced through the third hole.

In addition, Figure 9 shows a gas measuring device equipped with a humidity sensor 300, but depending on the performance of the humidity buffer 222, it may not be equipped with a humidity sensor 300, and this will be discussed in Figure 10. .

Figure 10 is a conceptual diagram for explaining a gas measuring device according to another embodiment of the present invention.

The present invention may include an electrochemical gas sensor 200, a fourth housing 220, and a humidity buffer 222.

The electrochemical gas sensor 200 may be provided on the substrate 500, and the electrochemical gas sensor 200 is cased by a separate first housing 210, and seals the first hole of the first housing 210. and may include a first diffusion barrier 211 that diffuses and transmits air introduced through the first hole.

The humidity buffer 222 can reversibly absorb or release water molecules (a) introduced through the fourth hole of the fourth housing 220, and any material including inorganic, organic, and polymer can be used.

The humidity buffer 222 may be provided by being applied to at least one side of the fourth housing 220 .

The humidity buffer 222 is configured to reversibly absorb and release the water molecules (a) introduced through the fourth hole of the fourth housing 220, rather than irreversibly, and serves to buffer changes in humidity. can do.

At this time, the humidity buffer 222 can reversibly absorb and release water molecules enough to sufficiently offset changes in humidity inside the fourth housing 220.

Through the humidity buffer 222, the electrochemical gas sensor 220 may not be affected by changes in humidity. That is, the measured value of the electrochemical gas sensor 220 may not include disturbance due to changes in humidity.

Accordingly, the gas measuring device according to FIG. 10 may not include the compensation unit 400 and the humidity sensor 300 described in FIG. 5 .

Below, we will look at the rate and size of humidity change depending on the presence or absence of a humidity buffer in relation to FIGS. 9 and 10.

FIG. 11 is a diagram to explain that the rate of change in internal humidity of an electrochemical gas sensor varies depending on conditions, and FIG. 12 is a diagram to explain that the magnitude of change in internal humidity of an electrochemical gas sensor varies depending on conditions.

11 and 12 illustrate cotton as a humidity buffer, but the humidity buffering agent is not limited thereto, and any material including inorganic, organic, and polymer that reversibly absorbs and releases water molecules can be used.

In addition, Figures 11 and 12 include graphs for the case where there is only an electrochemical gas sensor, the case where the electrochemical gas sensor is cased in a housing, and the case where a humidity buffer is included after the electrochemical gas sensor is cased in a housing.

Looking specifically, FIG. 11 is a diagram illustrating the effect of the housing and humidity buffer on the speed and magnitude of humidity change inside the electrochemical gas sensor.

If there is only an electrochemical gas sensor, it can be seen that the humidity change inside the electrochemical gas sensor is fast and large in size.

On the other hand, when the electrochemical gas sensor is cased in a housing, it can be seen that the speed of humidity change slows down and its size decreases.

Moreover, when the humidity buffer is included in the housing, it can be seen that the rate of humidity change is more than four times slower than when the housing and humidity buffer are not present, and its size is also reduced by more than two times.

FIG. 12 is a diagram for explaining the disturbance of the measured value measured by the electrochemical gas sensor in response to the change in humidity in FIG. 11.

If there is only an electrochemical gas sensor, it can be seen that the disturbance of the measured value measured by the electrochemical gas sensor has a large range up and down.

On the other hand, when the electrochemical gas sensor is cased with a housing, it can be seen that the width of the disturbance in the measured value decreases vertically.

Moreover, when a humidity buffer is included in the housing, it can be seen that the disturbance of the measured value is reduced by more than two times in the vertical direction.

Figures 11 and 12 disclose an example in which disturbance is included in measured values from an electrochemical gas sensor even if a humidity buffer is included. However, if the humidity buffer sufficiently buffers the humidity change, the disturbance may not be included in the measured value from the electrochemical gas sensor. This is the case of FIG. 10 , and in this case, the gas measuring device may not be equipped with a separate humidity sensor or a compensation unit that compensates for the measured value of the electrochemical gas sensor using data measured from the humidity sensor.

The above detailed description should not be construed as restrictive in any respect and should be considered illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

200: Electrochemical gas sensor 210: First housing
211: first diffusion barrier 220: third and fourth housings
221: third and fourth diffusion barriers 222: humidity buffer
300: Humidity sensor 310: Second housing
311: second diffusion barrier 400: compensation unit
500: substrate

Claims (11)

In the gas measuring device,
An electrochemical gas sensor that measures the concentration of a specific gas in the air by generating an electric current through a redox reaction with the specific gas;
Humidity sensor to detect changes in humidity;
Compensating unit for compensating the measured value of the electrochemical gas sensor based on the change in humidity measured by the humidity sensor,
The electrochemical gas sensor is
A first housing including a first hole through which air flows into one side and forming the external shape of the electrochemical gas sensor,
The humidity sensor is
It is provided in the gas measuring device to detect the same humidity change as the humidity change occurring inside the electrochemical gas sensor, and is included in a second housing that includes a second hole through which air flows in on one side and forms a receiving space. Characteristically,
The first housing is
It further includes a first diffusion barrier that seals the first hole and diffuses and transmits air introduced through the first hole,
The second housing is
A gas measuring device further comprising a second diffusion barrier that seals the second hole and diffuses and transmits air introduced through the second hole. delete According to paragraph 1,
The size of the second hole is
A gas measuring device characterized in that it is formed in response to a change in humidity inside the first housing through the first hole. delete According to paragraph 1,
The second diffusion barrier is
A gas measuring device, characterized in that the thickness, size and number of holes are formed in response to changes in humidity inside the first housing through the first diffusion barrier. According to paragraph 1,
The gas measuring device is
A gas measuring device further comprising a third housing including the electrochemical gas sensor and the humidity sensor and including a third hole through which air flows.
According to clause 6,
The third housing is
A gas measuring device comprising a third diffusion barrier that seals the third hole and diffuses and transmits air introduced through the third hole.
According to clause 6,
The third housing is
A gas measuring device comprising a humidity buffer that reversibly absorbs or releases water molecules introduced through the third hole.
According to clause 8,
The humidity buffering agent is
A gas measuring device, characterized in that it is applied to at least one side of the third housing.
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