JP2000171424A - Visualization and measuring apparatus for odor gas flow - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a visualization and measuring apparatus in which the selection of the arrangement position of a gas sensor is not required and by which the direction of an odor gas flow can be judged in a short time and with high reliability by a method wherein a change in the concentration of the odor gas flow is measured by a sensor array in many points and the change in the concentration is visualized. SOLUTION: A sensor array 3, a visualization means and an odor-gas flow-direction and flow-velocity measuring means are provided at this apparatus. The sensor array 3 uses pulse drive-type semiconductor gas sensor elements C11 to C15, C21 to C25, C31 to C35, C41 to C45, C51 to C55 so as to be arranged in a two-dimensional array shape. A control circuit 2 selects the sensor elements of one row portion from the sensor array 3, a power-supply voltage is applied, and heaters at the sensor elements on one row portion are heated momentarily. A log amplifier 4 is composed of operational amplifiers 4a to 4e. A current flows to only the sensor elements of one transverse row selected by the control circuit 2, The response of the five sensor elements of one transverse row is measured simultaneously. Rows are changed over sequentially. The response of all the sensor elements is measured. The response of the sensor elements is visualized as a dynamic image, and the direction of a gas flow and its flow velocity are judged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an odor / gas flow visualization device for visualizing the flow of odor / gas floating in the air as a moving image using a small sensor array in which gas sensors are arranged, and an odor / gas flow measurement device using the same. About.

[0002]

2. Description of the Related Art Conventionally, the following research has been conducted as a device for searching for a source of an odor or gas. (1) Yukio Hiranaka, Hiroo Yamazaki: Visualization of gas concentration distribution using semiconductor gas sensor array
of Sensor TechnologyResea
rch, ST-88-4, IEEE of Japan,
1988, pp. 33-42. A huge sensor array is manufactured by arranging gas sensors on a two-dimensional plane, and the entire image of the gas concentration distribution spreading from the source is measured. The resulting image is visualized on a computer screen, and the location of the source can be determined by searching for the location with the highest density. However, it is necessary to dispose the sensor in advance at a place where odor or gas is expected to be generated, which lacks versatility. (2) JP-A-7-12771 and JP-A-7-260618 In order to solve the above-mentioned problem (1), the inventor of the present application uses a small-sized device for determining the direction of a source, and moves in the obtained direction to generate A method of searching for the source was proposed. Using a sensor for determining the wind direction and a gas sensor, the direction of the generation source is determined by combining the gas concentration gradient measured at one point in the space with the wind direction. However, in an environment where the wind is unstable, the reliability of the direction determination is low due to the influence of local wind turbulence. In addition, since there are few wind direction sensors applicable to a fine wind speed of 5 cm / s or less as in a general room, it has been difficult to use in such an environment. (3) JP-A-8-261893, Japanese Patent Application No.8-12199
6. In order to solve the problem of the wind direction sensor in the above (2), the inventor of the present application has proposed a source direction determining apparatus that does not use the wind direction sensor. Gas is sucked from the front using a small fan, and the response difference of gas sensors arranged in front of the fan is measured to determine the direction of the odor / gas source. However, similar to the above (2), since the determination is performed based on the information obtained at one point in the space, there is a problem that it is easily affected by local wind turbulence.

[0003]

As described above,
Conventionally, when determining the direction of the odor / gas source, there has been a problem that it is difficult to select an arrangement position of the gas sensor or that the gas sensor is easily affected by local wind turbulence.

Accordingly, the present invention provides a multipoint measurement of gas concentration change (substantially simultaneous multipoint measurement) using a large number of gas sensors.
, It is less susceptible to local turbulence in the wind, enables highly reliable direction determination in a short time, and uses a portable small sensor array to determine the direction of the odor and gas source. , There is no need to arrange a sensor in advance around the source of the odor / gas flow, and a highly versatile odor / gas flow visualization device and an odor / gas flow measurement device using the same are provided. The purpose is to:

That is, according to the odor / gas flow visualization apparatus of the present invention, a small sensor array in which gas sensors are arranged is used, and the flow of odor / gas floating in the air flowing off the small sensor array as a moving image. By visualizing and moving according to the indicated direction, it is possible to easily and accurately find the source of the odor or gas. In addition, the wind direction and wind speed can be measured from the direction and speed of gas flow.

[0006]

An odor / gas flow visualization device according to the present invention comprises a sensor array in which a plurality of gas sensors are arranged on a two-dimensional plane, and multi-point measurement of a change in concentration of the odor / gas flow using the sensor array. (Substantially simultaneous multi-point measurement) and the visualization means for visualizing the measured change in concentration eliminates the need to select the location of the gas sensor, and the effect of local turbulence in the wind This makes it possible to determine the direction of the odor / gas flow with high reliability in a short time.

An odor / gas flow measuring device according to the present invention comprises: a sensor array in which a plurality of gas sensors are arranged on a two-dimensional plane;
This sensor array measures the concentration change of the odor / gas flow at multiple points (substantially simultaneous multipoint measurement) and visualizes the measured concentration change, and a odor / gas flow based on the visualized concentration change. Equipped with measuring means for measuring the direction and flow velocity of the gas flow, there is no need to select the location of the gas sensor, it is less susceptible to local turbulence in the wind, and has a highly reliable odor in a short time.・ Measurement of gas flow direction and flow velocity

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. (Configuration and Operation) FIG. 1 shows a configuration example of an odor / gas flow visualization device according to the present embodiment. The sensor array 3 used in this device is a pulse-driven semiconductor gas sensor element (for example, TGS2440, Figaro Giken).
C11 to C15, C21 to C25, C31 to C35, C
25 to 41 to C45 and C51 to C55
They are arranged in a two-dimensional array of 5 rows. Array 3
Is 55 mm, for example.

In order to detect a rare gas floating in the air, a highly sensitive sensor is required. Also, if a large number of sensors generating a large amount of heat are used side by side in a low wind speed environment, the array itself causes convection and changes the flow. For this reason,
A sensor with low current consumption is desirable.

A conventional semiconductor gas sensor has a disadvantage that the power consumption of the heater for heating the element is large. Since the pulse-driven sensor used in the present embodiment is used by heating the element instantaneously only when measuring a response, the power consumption of the heater is small, and even if many sensors are arranged, the heat generation is small.

The personal computer 1 controls the entire apparatus. In response to a command from the computer 1, the control circuit 2 sends one row of sensors (5
), A power supply voltage is applied, and the heaters of the selected one row of sensors are instantaneously heated. When a semiconductor gas sensor detects a gas, the electric resistance decreases and the current flowing through the element increases.

The logarithmic conversion circuit 4 performs logarithmic conversion of this current change, converts the logarithmic change from an analog signal to a digital signal by the A / D converter 5, and then takes the measured value into the computer 1.

The logarithmic conversion circuit 4 is composed of five sets of operational amplifiers (logarithmic amplifiers) 4a to 4e, and one circuit is connected in parallel with the sensors in one column of the sensor array 3.
That is, the sensor response signals from the sensor elements C11 to C15 are input to the operational amplifier 4a,
The sensor response signal from 25 is input to the operational amplifier 4b,
Sensor response signals from the sensor elements C31 to C35 are input to the operational amplifier 4c, sensor response signals from the sensor elements C41 to C45 are input to the operational amplifier 4d, and sensor response signals from the sensor elements C51 to C55 are input to the operational amplifier 4e.
Is being entered.

Of these, current flows only to the sensors in one horizontal row selected by the control circuit 2, and at the same time, the response of five sensors in one horizontal row is measured. By sequentially switching the rows to be selected, the responses of all 25 sensors are measured, and this operation is repeated at intervals.

Next, the operation of the sensor array 3 of FIG. 1 will be described with reference to the timing chart shown in FIG.

H1 to H5 in FIG. 1 are power supply lines for driving the heaters of the sensor elements of the sensor array 3. As shown in FIG. 2, first, a heater voltage pulse having a width T1 is applied to the power supply line H1, and the five sensor elements C11, C21, C31, C41, and C51 arranged in the first row (the top row) are heated. I do. When all the elements are heated simultaneously, a large current flows instantaneously even if a pulse drive element is used. Therefore, a method of heating each row is adopted. The power supply voltage at this time is, for example, 5 V, and the heater voltage pulse is repeatedly applied, for example, every cycle T2 = 0.25 seconds.

The measurement of the sensor response is performed every T3 seconds after the application of the heater voltage pulse.

S1 to S5 in FIG. 1 are power supply lines for measuring the resistance of the sensor element. As shown in FIG. 2, the power supply line S1 has a width 1
When a voltage pulse of 5 ms is applied, a current flows through the five sensor elements C11, C21, C31, C41, and C51 in the first row. This is amplified by the operational amplifiers 4a to 4e, and A / A
After converting the analog signal into a digital signal by the D converter 5, the value is measured by the personal computer 1.

Each of the operational amplifiers 4a to 4e is connected in parallel with one row of sensor elements in the sensor array 3. A voltage is applied to only one row of sensor elements to which a voltage pulse is applied. Electric current flows through.

As shown in FIG. 2, the above operation is performed, for example, in one step.
The processing is performed for all the rows at intervals of 5 ms.

The personal computer 1 calculates the element resistance of the sensor from the measured current value, and calculates the sensor response r according to the following equation.

R = Rgas / Rair (1) where Rgas is the element resistance of the sensor in the gas, Rair
Represents the element resistance of the sensor in air, and r is a monotonically decreasing function of the gas concentration.

FIG. 3 shows a response calibration curve for the ethanol gas of the pulse-driven semiconductor gas sensor used in the present embodiment.
Shown in In the figure, the ratio of the sensor resistance Rgas in gas to the resistance Rair in air, Rgas / Rair
Was used as the sensor response r. It can be seen that the sensor response r = Rgas / Rair decreases in response to a lean ppm level of gas.

Now, in order to visualize the obtained sensor response, the level of the gas concentration is represented by the density of black and white (image brightness). By displaying the brightness b of the pixel as b = 255 × (1-r) (2), a brighter image can be obtained in a place where the gas concentration is higher and r is smaller. Here, the coefficient 255
Is the number of shades of gray that can be displayed on the personal computer 1. (Gas Flow Visualization Experiment) The odor / gas flow visualization experiment using the odor / gas flow visualization device described above was performed in a wind tunnel as shown in FIG. The gas sensor array 3 was installed almost at the center of the wind tunnel, and the wind was generated using the AC fan 11. As a gas generation source, a nozzle for ejecting ethanol saturated steam is used, and the ejection amount from the ejection port 12 is 5
ml / min. The distance between the ejection port 12 and the sensor array 3 is 45 cm.

The diffusion rate of odor and gas molecules is very slow,
The gas molecules emitted from the jet port 12 are carried by the wind and spread. If the wind in the wind tunnel is completely laminar, the gas spreads leeward from the jet 12 like a continuous band.
However, the wind in the wind tunnel shown in FIG. 3 is disturbed as in the real environment, and the gas distribution fluctuates. For this reason, a gas cloud having a pattern with a high gas concentration and a low gas concentration flows downwind on the sensor array 3 like smoke flowing from a chimney.

Five sensor elements arranged in parallel with the wind are selected from the 25 sensor elements of the sensor array 3, and their sensor responses r are shown in FIG. The sensor element shown in FIG. 20, no. 19, no. 18, No. 1
7, no. They are arranged in the order of 16. When responding to the gas from FIG. It can be seen that the response value of 20 starts decreasing first, and then responds in the order in which the sensor elements are arranged. Conversely, although not shown in FIG. 5, the response values also start to increase in the same order when the sensor starts to recover. This order of response / recovery corresponds to the direction of the gas flow.

Therefore, the sensor responses r of the 25 sensor elements of the sensor array 3 are visualized on a computer screen,
Observe.

FIG. 6 shows the sensor array 3 in such a situation.
25 shows the results of visualizing the 25 sensor responses as a moving image. FIGS. 7A to 7D show images when the sensor element starts responding to gas, and FIGS. 7E to 7H show images when the gas starts passing and the sensor starts to recover. Although the white portion of the color represents a high concentration gas, in FIG. 6, the sensor response is binarized so that the movement of the visualized image is easy to see, and a plain (white) rectangle is placed at the position of the responding sensor. Diagonal diagonal lines (dark color) in places where sensors are not responding
I drew a rectangle.

As is clear from FIG. 6, it was confirmed that the gas was flowing from left to right. (Direction Estimation Algorithm) If the visualization image of the gas flow as shown in FIG. 6 is obtained by the odor / gas flow visualization apparatus as described above, the direction of the gas flow can be judged by a person. It is also possible to automatically determine the direction and the flow velocity using various image processing algorithms. The process of determining the direction and the flow velocity from the visualized image of the gas flow can be performed by the personal computer 1 in FIG.

Here, it is considered that a future calculation is made into a circuit and a real-time process is performed, and a direction estimation method (BKP.
Horn, "Robot Vision" Asakura Shoten, 305-3
28, 1993) will be described.

It is assumed that the molecular diffusion of the gas is ignored and the visualized gas concentration distribution flows two-dimensionally over the sensor array 3 while maintaining a constant shape. Assuming that the x-axis component of the gas flow is u and the y-axis component is v, the optical flow constraint equation is

[0032]

(Equation 1)

## EQU1 ##

The image luminance of the i-th row and the j-th column is defined as bij,
When the differentiation included in the above equation (3) is approximated by central difference,

[0035]

(Equation 2)

However, the arrangement interval Δl = 11 mm of the sensor elements of the sensor array 3 and the sampling time Δt = 250 m
s. The velocity vector (u, v) of the gas flow is
The above equation (4) is simultaneously established for i = 2, 3, 4 and j = 2, 3, 4 and can be obtained by the least square method.

Here, the visualized image shown in FIG.
FIG. 7 shows the result of estimating the direction and flow velocity of the gas flow according to the above-described method.

In the direction estimation, the sampling period Δt = 25
The measurement was performed every 0 ms, but the result shown in FIG. 6 shows the estimated value at the intermediate time between the adjacent images in FIG. The direction was set to 0 ° in the right direction and positive in the counterclockwise direction. A direction roughly corresponding to the moving direction of the image shown in FIG. 6 was obtained. The wind direction in the wind tunnel fluctuates around 0 °, and the obtained direction is consistent with this.

The speed of the obtained gas flow at the time of recovery was smaller than that at the time of the response of the sensor. This is because the recovery speed of the sensor was slower than the response speed. It is preferable to use a sensor whose recovery of the sensor response is sufficiently fast in order to visualize it. Alternatively, the operating condition of the sensor can be optimized to increase the speed of recovery of the sensor response.

For example, since the response characteristics of the sensor change depending on the set values of T1 and T3 described above, the operating conditions of these gas sensors may be optimized first.

That is, the above-described heater voltage pulse width T1
Is smaller, the recovery time of the sensor response to the ethanol gas is shorter, and the response sensitivity of the sensor also depends on the data measurement timing T3, and decreases as the value of T1 decreases. Therefore, considering the balance between the sensitivity and the recovery speed, the values of T1 and T3 may be set so that the recovery is performed at a high speed while keeping the sensitivity substantially equal.

By optimizing the operating conditions of the gas sensor and improving the recovery speed of the sensor corresponding to ethanol gas, it is possible to visualize the gas flow at a flow rate of approximately 1 to 2 cm / s. (Summary) As described above, according to the odor / gas flow visualization device for searching for a source of odor / gas floating in the air of the present invention, a small sensor array 3 in which 5 × 5 pulse-driven semiconductor gas sensors are arranged. And visualizes the gas flow passing over the array by capturing the sensor response as a moving image. Determine the direction of the gas flow from the obtained image,
Follow this to search for a gas source. Although multipoint measurement (small time difference in units of rows as described in the present embodiment (small measurement time difference in which a change in gas flow concentration can be ignored) is permitted, substantially all gas sensors in the sensor array 3 are allowed. And simultaneous multi-point measurement) to measure the change in gas concentration, it is possible to determine the direction with high reliability in a short time. Further, the direction and speed of the wind carrying gas can be obtained from the moving direction and speed of the image.

As a result of conducting a gas flow visualization experiment in a wind tunnel, it was confirmed that a minute gas flow of about 2 cm / s could be visualized and the direction of the gas flow could be correctly estimated using the gas flow. It can be expected to be applied to low wind speed environment and wind turbulence environment where it was difficult.

As described above, according to the above-described embodiment, the gas flow direction can be determined with high reliability in a short time, and an odor / gas source can be easily searched. The target to be searched may be a gas leak location or a fire location. In addition to displaying the obtained image and allowing a person to determine the gas flow direction, it is also possible to automatically determine the direction by using various image processing techniques.
If this is attached to a mobile robot, it can be applied to the detection of dangerous gas sources. At present, there are few effective measurement means for the wind speed. However, if the gas is intentionally released into the air and the flow is visualized, the present device can be used as a fine wind speed / wind vane. Conventionally, various types of smoke have been used for visualization, but sedimentation occurs when the wind speed is on the order of cm / s. Since the gas has higher followability with respect to the wind, the present apparatus is effective in a weak wind speed field.

[0045]

As described above, according to the present invention,
There is no need to select the location of the gas sensor, and the location of the gas sensor is less likely to be affected by local turbulence in the wind, and highly reliable odor / gas flow direction determination can be performed in a short time.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of an odor / gas flow visualization device according to an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the sensor array 3 of FIG.

FIG. 3 is a diagram showing a response calibration curve of a pulse-driven semiconductor gas sensor with respect to ethanol gas.

FIG. 4 is a diagram showing a configuration example of a wind tunnel in which an odor / gas flow visualization experiment was performed using an odor / gas flow visualization device.

FIG. 5 is a diagram showing an example of a change with time of sensor responses of five sensor elements arranged in parallel with the wind direction.

FIG. 6 is a diagram showing an example of a moving image in which a sensor response of a sensor array 3 is visualized.

7 is a diagram showing a table summarizing the results of estimating the direction and flow velocity of a gas flow with respect to the visualized image shown in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Personal computer 2 ... Control circuit 3 ... Sensor array 4 ... Logarithmic conversion circuit 5 ... A / D converter

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 12, 1999 (1999.10.
12)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

[Title of the Invention] Smell / gas flow visualization measurement device

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

BACKGROUND OF THE INVENTION Using a small sensor array in which gas sensors are arranged, the flow of odor and gas floating in the air is visualized as a moving image, and the direction and flow velocity of the odor and gas flow are measured.
The present invention relates to a measuring device for visualizing a smell / gas flow .

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

Accordingly, the present invention provides a multipoint measurement of gas concentration change (substantially simultaneous multipoint measurement) using a large number of gas sensors.
, It is less susceptible to local turbulence in the wind, enables highly reliable direction determination in a short time, and uses a portable small sensor array to determine the direction of the odor and gas source. by performing, it is not necessary to advance the sensor is disposed around the source of odor and gas flow, and an object thereof is to provide a versatile smell gas flow visualization meter measuring device.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

That is, the odor / gas flow visualization meter of the present invention
According to the measuring device, using a small sensor array in which gas sensors are arranged, the flow of smell and gas floating in the air flowing down on the small sensor array is visualized as a moving image, and if it moves in the direction indicated by this, the source of odor and gas can be easily and accurately found, also,
The wind direction and speed can be measured from the direction and speed of gas flow.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

An odor / gas flow visualization measuring apparatus according to the present invention comprises a sensor array in which a plurality of gas sensors are arranged on a two-dimensional plane, and a odor / gas flow concentration change through the sensor array. and multi-point measurement (substantially simultaneous multi-point measurement), the measured density changes and visualizing means for visualizing, measuring means for measuring the direction you and flow rate of the odor gas flow on the basis of the visualized concentration change By eliminating the need to select the location of the gas sensor, it is less susceptible to local turbulence in the wind, and can reliably and reliably measure the direction and flow velocity of odor and gas flow in a short time. Becomes

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Deleted

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. (Structure and Operation) FIG. 1 shows an example of the structure of an odor / gas flow visualization measuring device according to the present embodiment. The sensor array 3 used in this apparatus includes pulse-driven semiconductor gas sensor elements (for example, TGS2440, Figaro Giken) C11 to C15, C21 to C25, C31 to C3.
5, 25, C41 to C45, and C51 to C55 are used and arranged in a two-dimensional array of 5 rows and 5 columns. The length of one side of the array 3 is, for example, 55 mm.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction contents]

Now, in order to visualize the obtained sensor response, the level of the gas concentration is represented by the density of black and white (image brightness). By displaying the brightness b of the pixel as b = 255 × (1-r) (2), a brighter image can be obtained in a place where the gas concentration is higher and r is smaller. Here, the coefficient 255
Is the number of shades of gray that can be displayed on the personal computer 1. (Gas Flow Visualization Experiment) The odor / gas flow visualization experiment using the odor / gas flow visualization measurement device described above was performed in a wind tunnel as shown in FIG. The gas sensor array 3 was installed almost at the center of the wind tunnel, and the wind was generated using the AC fan 11. In addition, as a gas generation source, a nozzle for ejecting ethanol saturated vapor was used, and the ejection amount from the ejection port 12 was 5 ml / min. Spout 12 and sensor array 3
Is 45 cm.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0029

[Correction method] Change

[Correction contents]

As is clear from FIG. 6, it was confirmed that the gas was flowing from left to right. (Direction Estimation Algorithm) If the visualization image of the gas flow as shown in FIG. 6 is obtained by the odor / gas flow visualization measurement device as described above, the direction of the gas flow can be judged by a person. It is also possible to automatically determine the direction and the flow velocity using various image processing algorithms. The process of determining the direction and the flow velocity from the visualized image of the gas flow can be performed by the personal computer 1 in FIG.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction contents]

By optimizing the operating conditions of the gas sensor and improving the recovery speed of the sensor corresponding to ethanol gas, it is possible to visualize the gas flow at a flow rate of approximately 1 to 2 cm / s. (Summary) As described above, according to the odor / gas flow visualization measurement device for searching for the source of odor / gas drifting in the air of the present invention, a small sensor array in which 5 × 5 pulse-driven semiconductor gas sensors are arranged 3 and capturing the sensor response as a moving image, visualizing the gas flow passing over the array, determining the direction of the gas flow from the obtained image,
Follow this to search for a gas source. Although multipoint measurement (small time difference in units of rows as described in the present embodiment (small measurement time difference in which a change in gas flow concentration can be ignored) is permitted, substantially all gas sensors in the sensor array 3 are allowed. And simultaneous multi-point measurement) to measure the change in gas concentration, it is possible to determine the direction with high reliability in a short time. Further, the direction and speed of the wind carrying gas can be obtained from the moving direction and speed of the image.

[Procedure amendment 12]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 Visualization of an odor / gas flow according to an embodiment of the present invention.
The figure which showed the structural example of the measuring device.

FIG. 2 is a timing chart for explaining the operation of the sensor array 3 of FIG.

FIG. 3 is a diagram showing a response calibration curve of a pulse-driven semiconductor gas sensor with respect to ethanol gas.

FIG. 4 is a diagram showing a configuration example of a wind tunnel in which an odor / gas flow visualization experiment was performed using an odor / gas flow visualization device.

FIG. 5 is a diagram showing an example of a change with time of sensor responses of five sensor elements arranged in parallel with the wind direction.

FIG. 6 is a diagram showing an example of a moving image in which a sensor response of a sensor array 3 is visualized.

7 is a diagram showing a table summarizing the results of estimating the direction and flow velocity of a gas flow with respect to the visualized image shown in FIG. 6;

[Description of Signs] 1 ... Personal computer 2 ... Control circuit 3 ... Sensor array 4 ... Logarithmic conversion circuit 5 ... A / D converter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Yamanaka 8-7-2 Arima, Miyama-ku, Kawasaki-shi, Kanagawa 411 Canon Arima Dormitory 411 (72) Inventor Naoya Kushida 3219-11 Iiyama, Atsugi-shi, Kanagawa 2G046 AA00 AA01 BA07 BJ06 CA04 DB07 DC13 DC15 DD03 EB01

Claims (2)

[Claims] 1. A sensor array in which a plurality of gas sensors are arranged on a two-dimensional plane, and a visualization means for measuring a concentration change of an odor / gas flow at a plurality of points with the sensor array and visualizing the measured concentration change. An odor / gas flow visualization device, comprising: 2. A sensor array in which a plurality of gas sensors are arranged on a two-dimensional plane, and visualization means for measuring a change in concentration of an odor / gas flow at multiple points with the sensor array and visualizing the measured change in concentration. Measuring means for measuring the direction and the flow velocity of the odor / gas flow based on the visualized change in concentration, and an odor / gas flow measurement device.