JP7317686B2 - gas detector - Google Patents

Description

The present disclosure relates to a gas detection device and gas detection method.

2. Description of the Related Art Conventionally, devices for detecting gas concentrations are known. For example, the device described in Patent Document 1 accurately analyzes the exhaust gas emitted from the engine of a hybrid vehicle.

JP 2019-117169 A

Here, as a gas detection device, there is a device that detects an odorous gas generated from stool excreted by a subject. In the case of detecting a target gas based on a specimen of a subject, the above-mentioned devices for detecting the concentration of exhaust gas differ greatly in the structure of the flow path of the sample gas, and the structure of the flow path of the sample gas is greatly different. The road structure has room for improvement.

An object of the present disclosure, which has been made in view of such points, is to provide a gas detection apparatus and a gas detection method capable of accurately analyzing a gas to be detected based on a specimen of a subject.

A gas detection device according to an embodiment of the present disclosure includes a gas sensor that detects the concentration of a gas to be detected contained in a sample gas, a supply unit that supplies the sample gas to the gas sensor, and the sample gas that has passed through the gas sensor. a valve capable of switching the output destination of to an exhaust path or a chamber storing the sample gas for analyzing the gas to be detected; and a control unit. The control unit controls an air supply speed of the supply unit so that the concentration of the detection target gas detected by the gas sensor becomes a first concentration, and controls the valve based on the concentration of the detection target gas. do.

A gas detection method according to an embodiment of the present disclosure detects the concentration of a gas to be detected contained in a sample gas, and supplies the sample gas such that the concentration of the gas to be detected becomes a first concentration. and controlling a valve based on the concentration of the gas to be detected so that the output destination of the sample gas is a chamber that stores the sample gas. .

According to an embodiment of the present disclosure, it is possible to provide a gas detection device and a gas detection method capable of accurately analyzing a gas to be detected based on a specimen of a subject.

FIG. 1 is an external view of a gas detection device according to an embodiment of the present disclosure. FIG. 2 is a diagram showing an example of the internal configuration of a housing included in the gas detection device. FIG. 3 is a functional block diagram of the gas detector. FIG. 4 is a circuit diagram of the sensor section. FIG. 5 is a diagram showing an example of control of the air supply speed of the supply unit by the control unit. FIG. 6 is a diagram illustrating changes in the concentration of the gas to be detected. FIG. 7 is an example of a flow chart of a gas detection method executed by the gas detection device. FIG. 8 is a diagram showing another example of control of the air supply speed of the supply unit by the control unit.

Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. Each figure is shown schematically.

[Configuration example of gas detector]
The gas detection device 1 shown in FIG. 1 is also called a "gas detection system". A gas detection device 1 shown in FIG. 1 detects gas generated from a specimen of a subject. The detected gas can be used for analysis of the subject's health condition, and the like. Here, the specimen of the subject may be, for example, a part of the tissue or urine of the subject, but in this embodiment, it is the stool of the subject.

The gas detection device 1 is installed, for example, in a flush toilet bowl 2, as shown in FIG. The toilet bowl 2 includes a toilet bowl 2A and a toilet seat 2B. The gas detection device 1 may be installed anywhere on the toilet bowl 2 . As an example, the gas detection device 1 may be arranged from between the toilet bowl 2A and the toilet seat 2B to the outside of the toilet 2, as shown in FIG. Part of the gas detection device 1 may be embedded in the toilet seat 2B. The toilet bowl 2A of the toilet bowl 2 can be discharged with feces of the subject. The gas detection device 1 can obtain a sample gas in which gas generated from stool discharged into the toilet bowl 2A is mixed with outside air. The gas detection device 1 can detect the concentration of a specific gas contained in the sample gas. The gas detection device 1 can transmit detection results to the electronic device 3 . Further, the housing 10, the suction hole 20 and the discharge path 22 will be described later.

The toilet bowl 2 can be installed in a toilet room such as a house or a hospital. Also, the electronic device 3 is, for example, a smart phone used by the subject. However, the electronic device 3 is not limited to a smart phone, and may be any electronic device. The electronic device 3 may be inside the toilet room or outside the toilet room.

The electronic device 3 can receive the detection result from the gas detection device 1 by wireless communication or wired communication. The electronic device 3 can display the received detection result on the display unit 3A. The display unit 3A may include a display capable of displaying characters and the like, and a touch screen capable of detecting contact with a user's (subject's) finger or the like. The display may include a display device such as a liquid crystal display (LCD), an organic electroluminescence display (OELD) or an inorganic electroluminescence display (IELD). . The detection method of the touch screen may be an arbitrary method such as a capacitance method, a resistive film method, a surface acoustic wave method (or an ultrasonic method), an infrared method, an electromagnetic induction method, or a load detection method.

As shown in FIG. 2, the gas detection device 1 includes a housing 10, a suction hole 20, a discharge path 22, a flow path 23, a valve 25, a chamber 30, a supply section 50, a gas sensor 63a, and a control unit 64 . Channel 23 includes channel 23-1, channel 23-2, and channel 23-3. Moreover, as shown in FIG. 3 , the gas detection device 1 includes a storage section 61 , a communication section 62 and a sensor section 63 . The sensor section 63 includes at least a gas sensor 63a. Furthermore, the gas detection device 1 may include a battery, a speaker, and the like. The configuration of the chamber 30 and the sensor section 31 will be described later.

The housing 10 accommodates various components of the gas detection device 1 . Housing 10 may be constructed of any material. For example, the housing 10 may be made of a material such as metal or resin.

The suction holes 20 may be exposed inside the toilet bowl 2A, as shown in FIG. A part of the suction hole 20 may be embedded in the toilet seat 2B. The suction hole 20 sucks a sample gas in which the gas generated from the stool discharged into the toilet bowl 2A is mixed with the outside air. The sample gas sucked by the suction hole 20 reaches the inlet of the supply section 50 through the channel 23-1. As shown in FIG. 1, one end of the suction hole 20 may be directed toward the interior of the toilet bowl 2A. As shown in FIG. 2 , the other end of the suction hole 20 may be connected to the supply section 50 . The suction hole 20 may be configured by a tubular member such as a resin tube or a metal or glass pipe.

Here, a blower may be provided outside the suction hole 20 . The blower may be configured including a fan and a motor. The blower is controlled by the controller 64 . When the motor is driven and the fan rotates, the sample gas is drawn into the vicinity of the suction hole 20 .

A portion of the discharge channel 22 may be exposed outside the toilet bowl 2A, as shown in FIG. The exhaust path 22 exhausts exhaust from the chamber 30 or sample gas not taken into the chamber 30 to the outside. The discharge path 22 may be configured by a tubular member such as a resin tube or a metal or glass pipe.

One end of the channel 23-1 is connected to the suction hole 20. As shown in FIG. The other end of the channel 23-1 is connected to the inlet of the supply section 50. As shown in FIG. One end of the channel 23 - 2 is connected to the outlet of the supply section 50 . The other end of the channel 23-2 is connected to the valve 25. As shown in FIG. One end of channel 23 - 3 is connected to valve 25 . The other end of channel 23 - 3 is connected to chamber 30 . The flow path 23 may be composed of a tubular member such as a resin tube or a metal or glass pipe.

The valve 25 is located between the channels 23-2, 23-3 and the discharge channel 22. As shown in FIG. The valve 25 includes a connection port connected to the channel 23-2, a connection port connected to the channel 23-3, and a connection port connected to the discharge channel 22. The valve 25 may be an electromagnetically actuated, piezo actuated or motor actuated valve.

By controlling the valve 25 by the controller 64, the connection state between the flow path 23-2, the flow path 23-3 and the discharge path 22 is switched. For example, the control unit 64 switches the connection state between them to a state in which the flow paths 23-2 and 23-3 are connected or a state in which the flow paths 23-2 and the discharge path 22 are connected. .

The gas sensor 63a detects the concentration of the detected gas contained in the sample gas. Here, the gas to be detected is gas generated from stool discharged into the toilet bowl 2A. The gas sensor 63a is provided in the channel 23-2 and detects the concentration of the gas to be detected contained in the sample gas passing through the channel 23-2. The concentration of the detected gas detected by the gas sensor 63 a is output to the control section 64 .

Chamber 30 stores a sample gas for analyzing the gas to be detected. The chamber 30 has therein a sensor section 31 different from the sensor section 63 described above. The chamber 30 may have multiple sensor units 31 . The sensor units 31-1, 31-2, and 31-3 are part of the plurality of sensor units 31. FIG. Chamber 30 may be divided into a plurality. Each sensor unit 31 may be arranged in each chamber 30 divided into a plurality. Each chamber 30 divided into a plurality may be connected. Chamber 30 is connected to channel 23-3. A sample gas is supplied to the chamber 30 from the channel 23-3. Chamber 30 is also connected to exhaust channel 22 . Exhaust from chamber 30 , including sample gas after detection processing, is exhausted through exhaust path 22 .

The sensor unit 31 is arranged inside the chamber 30 . The sensor section 31 detects the type and concentration of the gas to be detected. In this embodiment, each sensor unit 31 detects a specific type of gas and outputs a voltage corresponding to the concentration to the control unit 64 . Based on the voltage acquired from the sensor unit 31, the control unit 64 can analyze the composition ratio of the gas to be detected, its change, and the like. Here, the sample gas supplied to the chamber 30 includes a gas to be detected and a gas not to be detected. Examples of gases to be detected include methane, hydrogen, carbon dioxide, methyl mercaptan, hydrogen sulfide, acetic acid, and trimethylamine. Gases not to be detected are, for example, ammonia and water.

The sensor section 31, as shown in FIG. 4, includes a sensor element 31S and a resistance element 31R. The sensor element 31S and the resistance element 31R are connected in series between the power supply terminal P1 and the ground terminal P2. A constant voltage value _VC is applied between the power terminal P1 and the ground terminal P2. The same current value _IS flows through each of sensor element 31S and resistance element 31R. The current value I _S can be determined according to the resistance value R _S of the sensor element 31S and the resistance value R _L of the resistance element 31R. The voltage output by the sensor unit 31 may be the voltage value _VS applied to the sensor element 31S or the voltage value _VRL applied to the resistance element 31R.

A power terminal P1 shown in FIG. 4 is connected to a power source such as a battery provided in the gas detection device 1 . A ground terminal P2 is connected to the ground of the gas detection device 1 .

One end of the sensor element 31S shown in FIG. 4 is connected to the power terminal P1. The other end of the sensor element 31S is connected to one end of the resistance element 31R. The sensor element 31S is a semiconductor sensor. However, the sensor element 31S is not limited to a semiconductor sensor. For example, the sensor element 31S may be a catalytic combustion sensor, a solid electrolyte sensor, or the like.

The sensor element 31S includes a gas sensitive portion. The gas sensitive portion contains a metal oxide semiconductor material corresponding to the type of sensor portion 31 . Examples of metal oxide semiconductor materials include silicon oxide (such as _SnO2 ), indium oxide (such as _In2O3 ), zinc oxide (such as _ZnO ), tungsten oxide (such as _WO3 ) and iron oxide (such as _{Fe2O3 )} . ) and the like. By appropriately adding impurities to the metal oxide semiconductor material of the gas sensitive portion, the gas to be detected by the sensor element 31S can be appropriately selected. The sensor element 31S may further include a heater that heats the gas sensitive portion.

When the sensor element 31S is exposed to the sample gas, the gas to be detected contained in the sample gas is replaced with oxygen adsorbed on the surface of the gas sensitive portion of the sensor element 31S, and a reduction reaction can occur. Oxygen adsorbed on the surface of the gas-sensitive portion can be removed by the reduction reaction. When the oxygen adsorbed on the surface of the gas sensitive portion is removed, the resistance value _R.sub.2S of the sensor element 31S may decrease, and the voltage value _V.sub.S applied to the sensor element 31S may decrease. In other words, when the sample gas is supplied to the sensor section 31, the voltage value _VS applied to the sensor element 31S may decrease according to the concentration of the gas to be detected contained in the sample gas. Here, the sum of the voltage value _VS and the voltage value _VRL is constant. Therefore, when the sample gas is supplied to the sensor section 31, the voltage value _VRL can increase according to the concentration of the gas to be detected contained in the sample gas.

The resistance element 31R is a variable resistance element. A resistance value _RL of the resistance element 31R can be changed by a control signal from the control section 64. FIG. One end of the resistance element 31R is connected to the other end of the sensor element 31S. The other end of the resistive element 31R is connected to the ground terminal P2.

By adjusting the resistance value _RL of the resistance element 31R, the voltage value _VS applied to the sensor element 31S can be adjusted. For example, if the resistance value _RL is made equal to the resistance value _RS of the sensor element 31S, the amplitude of the voltage value _VS applied to the sensor element 31S can be close to the maximum value.

The supply unit 50 is provided between the channels 23-1 and 23-2. The supply unit 50 supplies the sample gas to the gas sensor 63a. The arrows on the feed 50 in FIG. 2 indicate the directions in which the feed 50 delivers the sample gas. The supply unit 50 is driven or stopped under control of the control unit 64 . Also, the supply unit 50 may be a pump capable of adjusting the air supply speed by the degree of opening of the valve. The supply unit 50 may be composed of a piezo pump, a motor pump, or the like. As another example, the supply unit 50 may be a blower capable of adjusting the air supply speed according to the rotation speed of the fan. Here, as another configuration example, the supply unit 50 may be provided between the gas sensor 63 a and the valve 25 . At this time, the sample gas drawn into the supply unit 50 from the suction hole 20 is supplied to the gas sensor 63a.

The storage unit 61 is composed of, for example, a semiconductor memory, a magnetic memory, or the like. The storage unit 61 stores various information and programs for operating the gas detection device 1 . The storage unit 61 may function as a work memory. Further, the storage unit 61 may store, for example, a multiple regression analysis algorithm, a prediction formula, and the like for analyzing in detail the gas to be detected detected by the sensor unit 31 .

The communication unit 62 communicates with the electronic device 3 to present the analysis result of the gas to be detected by the control unit 64 to the subject by, for example, display on the display unit 3A or voice. The communication unit 62 may be capable of communicating with an external server. The communication method used for communication between the communication unit 62 and the electronic device 3 and the external server may be a short-range wireless communication standard, a wireless communication standard for connecting to a mobile phone network, or a wired communication standard. Near field communication standards may include, for example, WiFi (registered trademark), Bluetooth (registered trademark), infrared rays, and Near Field Communication (NFC). A wireless communication standard for connecting to a mobile phone network may include, for example, LTE (Long Term Evolution) or a mobile communication system of fourth generation or higher. The communication method used for communication between the communication unit 62 and the electronic device 3 and the external server may be a communication standard such as LPWA (Low Power Wide Area) or LPWAN (Low Power Wide Area Network).

The sensor section 63 may include at least one of an image camera, a personal identification switch, an infrared sensor, a pressure sensor, and the like, in addition to the gas sensor 63a. The sensor section 63 outputs the detection result to the control section 64 .

For example, when the sensor unit 63 includes an infrared sensor, it detects that the subject has entered the toilet room by detecting infrared light reflected from the object irradiated by the infrared sensor. can. The sensor unit 63 outputs a signal indicating that the subject has entered the toilet room to the control unit 64 as a detection result.

For example, when the sensor section 63 includes a pressure sensor, it can detect that the subject has sat on the toilet seat 2B by detecting the pressure applied to the toilet seat 2B shown in FIG. The sensor unit 63 outputs a signal indicating that the subject has sat on the toilet seat 2B to the control unit 64 as a detection result.

For example, when the sensor unit 63 includes a pressure sensor, it can detect that the subject stands up from the toilet seat 2B by detecting a decrease in the pressure applied to the toilet seat 2B shown in FIG. . The sensor unit 63 outputs to the control unit 64 a signal indicating that the subject has stood up from the toilet seat 2B as a detection result.

For example, when the sensor unit 63 includes an image camera, an individual identification switch, and the like, it collects data such as facial images, sitting height, and weight. The sensor unit 63 identifies and detects an individual from the collected data. The sensor unit 63 outputs a signal indicating the identified individual to the control unit 64 as a detection result.

For example, if the sensor section 63 includes an individual identification switch or the like, it identifies (detects) an individual based on the operation of the individual identification switch. In this case, personal information may be registered (stored) in advance in the storage unit 61 . The sensor unit 63 outputs a signal indicating the specified individual to the control unit 64 as a detection result.

Control unit 64 includes one or more processors. The processor may include at least one of a general-purpose processor that loads a specific program to execute a specific function, and a dedicated processor that specializes in specific processing. A dedicated processor may include an Application Specific Integrated Circuit (ASIC). The processor may include a programmable logic device (PLD). The PLD may include an FPGA (Field-Programmable Gate Array). The control unit 64 may include at least one of SoC (System-on-a-chip) and SiP (System In a Package) with which one or more processors cooperate. The controller 64 may determine, for example, the timing of storing a sample gas, which will be described later, in the chamber 30 according to a program.

[Sample gas storage timing]
Here, in order to accurately analyze the gas to be detected based on the specimen of the subject, the gas to be detected must be stored in the chamber 30 at an appropriate concentration. The gas to be detected is sucked together with the outside air by the supply unit 50 . If the speed at which the supply unit 50 sucks, that is, the air supply speed is high, dilution by the outside air increases, so the concentration of the gas to be detected in the sample gas decreases. If the concentration of each component of the gas to be detected decreases more than necessary, it becomes difficult to analyze the gas to be detected with high accuracy. Further, when the air supply speed of the supply unit 50 is slow, dilution by the outside air becomes small, so the concentration of the gas to be detected in the sample gas increases. If the concentration of each component of the gas to be detected increases more than necessary, it may lead to overmeasurement of the concentration.

The gas detection device 1 according to the present disclosure causes the gas to be detected to be stored in the chamber 30 at an appropriate concentration by the following control described with reference to FIGS. 5 to 7. FIG. FIG. 5 is a diagram showing an example of control of the air supply speed of the supply unit 50 by the control unit 64. As shown in FIG. FIG. 6 is a diagram illustrating changes in the concentration of the gas to be detected detected by the gas sensor 63a. The vertical axis in FIG. 5 indicates the air supply speed of the supply unit 50 . The vertical axis in FIG. 6 indicates the concentration of the detected gas detected by the gas sensor 63a. The horizontal axis of FIG. 5 and the horizontal axis of FIG. 6 indicate time.

The control unit 64 starts the operation of the supply unit 50 at time ts. The controller 64 sets the air supply speed of the supply unit 50 to the first speed S1 from time ts when the supply unit 50 starts operating to time ta described later. The first speed S1 is set to, for example, the maximum air supply speed of the supply unit 50 or a speed close to the maximum speed. A speed close to the maximum speed is, for example, a speed of 70% or more of the maximum speed. Further, the control unit 64 sets the valve 25 so that the output destination of the sample gas that has passed through the gas sensor 63a is the exhaust passage 22 at the time ts. Here, the concentration of the detected gas detected by the gas sensor 63a is the concentration C0 at time ts. The concentration C0 is the concentration of the gas to be detected remaining in the flow path 23-2, and is, for example, zero or close to zero. A near-zero concentration is, by way of example, a concentration of less than 10%. When the supply unit 50 starts operating, the sample gas containing the gas to be detected is supplied to the channel 23-2, so that the concentration of the gas to be detected increases. After that, when the supply unit 50 continues to supply the sample gas at the first speed S1, the concentration of the gas to be detected becomes maximum at time ta. The maximum value is concentration C1.

In the present embodiment, the control unit 64 sets the concentration of the detected gas that first becomes maximum after the start of operation of the supply unit 50 as the first concentration. In the examples of FIGS. 5 and 6, the controller 64 sets the density C1 as the first density. After time ta, the control unit 64 controls the air supply speed of the supply unit 50 so that the concentration of the detection target gas detected by the gas sensor 63a becomes the first concentration. That is, the controller 64 controls the concentration of the gas to be detected to maintain the first concentration.

For example, as shown in FIGS. 5 and 6, the control unit 64 adjusts the air supply speed of the supply unit 50 during the first period PE1 from time ta when the concentration of the gas to be detected reaches the first concentration. , the concentration of the gas to be detected is set to the concentration C1. The first period PE1 is a sufficiently long period for stabilizing the concentration of the gas to be detected, and is longer than the period from time ts to time ta, for example. The controller 64 controls the valve based on the concentration of the gas to be detected. The control unit 64 controls the valve 25 so that the output destination of the sample gas is the chamber 30 when the first period PE1 has passed since the time ta when the concentration of the gas to be detected reaches the first concentration. In this embodiment, the control unit 64 causes the chamber 30 to retain the sample gas that has been exhausted until then at the time tb when the concentration of the gas to be detected is stabilized, as indicated by the characteristic curve F in FIG. Here, the characteristic curve F0 in FIG. 6 shows the concentration of the gas to be detected in a comparative example in which the sample gas starts to be stored while the air supply speed of the supply unit 50 remains at the first speed S1. In the comparative example, in the first period PE1, the control unit 64 does not perform control to set the concentration C1 as the first concentration. Therefore, since the suction speed is too high, the concentration of the gas to be detected is diluted.

FIG. 7 is an example of a flow chart of a gas detection method executed by the gas detection device 1 .

The gas detection device 1 detects the concentration of the target gas contained in the sample gas by the gas sensor 63a (step S1).

The gas detection device 1 controls the air supply speed of the supply unit 50 so that the concentration of the gas to be detected becomes the first concentration by the control unit 64 (step S2).

If the first concentration is reached and the first period PE1 has not elapsed (No in step S3), the gas detection device 1 returns to the process of step S1.

When the gas detection device 1 reaches the first concentration and the first period PE1 has passed (Yes in step S3), the control unit 64 controls the valve 25 so that the output destination of the sample gas is the chamber 30. (step S4).

As described above, the gas detection device 1 according to the present embodiment can accurately analyze the gas to be detected based on the specimen of the subject with the above configuration.

The figures describing the embodiments of the present disclosure are schematic. The dimensional ratios and the like on the drawings do not necessarily match the actual ones.

Although the embodiments of the present disclosure have been described with reference to drawings and examples, it should be noted that various variations or modifications can be easily made by those skilled in the art based on the present disclosure. Therefore, it should be noted that these variations or modifications are included within the scope of this disclosure. For example, the functions included in each component can be rearranged so as not to be logically inconsistent, and a plurality of components can be combined into one or divided.

For example, FIG. 8 is a diagram showing another example of control of the air supply speed of the supply unit 50 by the control unit 64. As shown in FIG. In the above-described embodiment, the control unit 64 determines the time ta as the time when the concentration of the gas to be detected first reaches its maximum after the operation of the supply unit 50 is started. In the modified example of FIG. 8, the control unit 64 sets the time when the supply unit 50 starts operating, that is, when the second period PE2 has passed since the time ts, as the time ta. The control unit 64 setting the air supply speed to the first speed S1 from the time ts to the time ta, and the control unit 64 setting the concentration of the gas to be detected at the time ta to the first concentration are the above-mentioned Same as the embodiment.

In the example of FIG. 8, the second period PE2 is a period obtained by dividing the capacity of the sample gas flow paths 23-1, 23-2 and 23-3 from the suction hole 20 to the chamber 30 by the first velocity S1. be. The control unit 64 may calculate the second period PE2 and store it in the storage unit 61 . At this time, the control unit 64 may set the first period PE1 longer than the second period PE2 so that the switching of the valve 25 is performed after the concentration of the gas to be detected is stabilized.

For example, in the above embodiment, as shown in FIG. 3, the gas detection device 1 is described as one device. However, the gas detection device 1 of the present disclosure is not limited to one device, and may include multiple independent devices.

Further, in the above-described embodiment, the sensor section 31 is provided inside the chamber 30, but the present invention is not limited to this. For example, the sensor section 31 may be arranged in the rear stage of the chamber 30 and the two may be connected by a pipe. That is, the sample gas from the valve 25 may be configured to pass through the sensor section 31 after passing through the chamber 30 which is the storage section. After the sample gas is stored, the output of the subsequent sensor section 31 may be read.

Descriptions such as “first” and “second” in the present disclosure are identifiers for distinguishing the configurations. Configurations differentiated in descriptions such as "first" and "second" in this disclosure may interchange the numbers in the configuration. The exchange of identifiers is done simultaneously. The configurations are still distinct after the exchange of identifiers. Identifiers may be deleted. Configurations from which identifiers have been deleted are distinguished by codes. The description of identifiers such as "first" and "second" in this disclosure should not be used as a basis for interpreting the order of the configuration or the existence of lower numbered identifiers.

Reference Signs List 1 gas detector 2 toilet 2A toilet bowl 2B toilet seat 3 electronic device 3A display 10 housing 20 suction hole 22 discharge path 23, 23-1, 23-2, 23-3 flow path 25 valve 30 chamber 31, 31-1 , 31-2, 31-3 sensor section 31S sensor element 31R resistance element 50 supply section 61 storage section 62 communication section 63 sensor section 64 control section P1 power supply terminal P2 ground terminal PE1 first period PE2 second period

Claims (7)

a gas sensor that detects the concentration of the gas to be detected contained in the sample gas;
a supply unit that supplies the sample gas to the gas sensor;
a valve capable of switching an output destination of the sample gas that has passed through the gas sensor to an exhaust path or a chamber storing the sample gas for analyzing the gas to be detected;
a control unit that controls the air supply speed of the supply unit so that the concentration of the detection target gas detected by the gas sensor becomes a first concentration, and controls the valve based on the concentration of the detection target gas; A gas detection device, comprising: 2. The control unit according to claim 1, wherein when the concentration of the gas to be detected reaches the first concentration and a first period has elapsed, the control unit controls the valve so that the output destination is the chamber. A gas detection device as described. 3. The gas detection device according to claim 1, wherein said control unit sets the concentration of said gas to be detected that first reaches a maximum after the start of operation of said supply unit as said first concentration. The control unit sets the air supply speed to a first speed until a second period elapses from the start of operation of the supply unit, and the second period elapses from the start of operation of the supply unit. Let the concentration of the gas to be detected at the time be the first concentration,
3. The gas detection device according to claim 2, wherein the second period is a period obtained by dividing the capacity of the flow path of the sample gas from the suction hole to the chamber by the first speed. 5. The gas detection device according to claim 4, wherein said first period is longer than said second period. 6. The gas detection device according to any one of claims 1 to 5, wherein said supply unit is a pump capable of adjusting an air supply speed according to the degree of opening of a valve. The gas detection device according to any one of claims 1 to 5, wherein the supply unit is a blower capable of adjusting an air supply speed according to the number of revolutions of a fan.

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