Gas detection device and gas detection system

Abstract

The present invention makes it possible to accurately detect the concentration of a component in a sample gas. The gas detection device comprises: a sampling unit; a first gas sensor; and a second gas sensor. The sampling unit samples a sample gas including a first detection-target gas and a second detection-target gas. The first and second gas sensors can detect both the first and second detection-target gasses. The first and second gas sensors are different from each other in a relative relationship between detection sensitivity for the first detection-target gas and detection sensitivity for the second detection-target gas.

Description

[Technical Field]

[0001] The present disclosure relates to a gas detection device that detects the concentration of a gas, and a gas detection system that includes the gas detection device. [Background technology]

[0002] A system for detecting odorous gases generated from feces excreted by a subject is known (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2016-145809 Summary of the Invention

[0004] A gas detection device according to one embodiment of the present disclosure includes a sample gas collection unit that collects a sample gas containing a first detectable gas and a second detectable gas, and a gas detection unit that includes a plurality of gas sensors, including a first gas sensor and a second gas sensor, that can detect both the first detectable gas and the second detectable gas contained in the sample gas, wherein the first gas sensor and the second gas sensor have different relative detection sensitivities to the first detectable gas and the second detectable gas. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is an external view illustrating an example of a configuration of an analysis system according to an embodiment of the present disclosure. [Figure 2] 1 is a schematic diagram illustrating an example of a configuration of a gas detection device according to an embodiment of the present disclosure. [Figure 3] 1 is a block diagram showing an example of a configuration of a gas detection device according to an embodiment of the present disclosure. [Figure 4] 10 is a graph showing an example of fluctuations in a first detection signal caused by hydrogen sulfide and methyl mercaptan. [Figure 5] 10 is a graph showing an example of fluctuations in the second detection signal caused by hydrogen sulfide and methyl mercaptan. [Figure 6] FIG. 2 is a partial cross-sectional view showing an example of the configuration of a first gas sensor included in the gas sensor group. [Figure 7] FIG. 10 is a schematic diagram showing an example of the configuration of a gas detection device according to a third embodiment. [Figure 8] FIG. 10 is a schematic diagram showing an example of the configuration of a gas detection device according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] [Embodiment 1] An embodiment of the present disclosure will be described in detail below.

[0007] <Analysis system 100> FIG. 1 is an external view showing an example of the configuration of an analysis system 100 according to an embodiment of the present disclosure. For the sake of convenience, the drawings referred to in this specification are schematic diagrams showing only some of the components in a simplified form to explain the embodiment. Therefore, the analysis system 100 may include any components not shown in the drawings referred to in this specification. Furthermore, the dimensions of the components in the drawings do not faithfully represent the actual dimensions of the components and the dimensional ratios of the components.

[0008] An analysis system 100 as shown in FIG. 1 may be referred to as a "gas detection system" or a "gas analysis system." As shown in FIG. 1, the analysis system 100 includes a gas detection device 1 and an electronic device (terminal device) 3. The gas detection device 1 detects gas generated from a specimen of a subject. The detected gas may be used for analyzing the subject's health status, etc. Here, the specimen of the subject may be, for example, a part of the subject's tissue or urine, but in this embodiment, it is the subject's stool. A chemical substance that is the target of detection by a gas sensor group 24 (described later) included in the gas detection device 1 and that can exist as a gas is referred to as a "detection target gas." There may be one type of detection target gas, or multiple types. The detection target gas may be contained in, for example, gas (sample gas) emitted from the subject's stool. The concentration of the detection target gas refers to the concentration of the chemical substance to be detected in the sample gas.

[0009] As shown in FIG. 1, the gas detection device 1 is installed in, for example, a flush toilet 2. The toilet 2 includes a toilet bowl 2A and a toilet seat 2B. The gas detection device 1 may be installed in any location on the toilet 2. As an example, the gas detection device 1 may be arranged between the toilet bowl 2A and the toilet seat 2B and outside the toilet 2, as shown in FIG. 1. A portion of the gas detection device 1 may be embedded in the toilet seat 2B. A subject's feces may be discharged into the toilet bowl 2A of the toilet 2. The gas detection device 1 may obtain a sample gas in which gas generated from the feces discharged into the toilet bowl 2A is mixed with outside air. The gas detection device 1 may detect the type and concentration of the target gas contained in the sample gas. The gas detection device 1 may transmit the detection results to the electronic device 3.

[0010] The toilet bowl 2 may be installed in a toilet room in a home, a hospital, or the like. The electronic device 3 is, for example, a smartphone used by the subject. However, the electronic device 3 is not limited to a smartphone and may be any electronic device. The electronic device 3 may be located inside or outside the toilet room.

[0011] The electronic device 3 may receive the detection results from the gas detection device 1 via wireless or wired communication. In this case, the electronic device 3 may receive the detection results from the gas detection device 1 via a server. The electronic device 3 may display the received detection results on the display unit 3A. The display unit 3A may be configured to 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 be configured to include a display device such as a liquid crystal display (LCD), an organic electroluminescence display (ELD), or an inorganic electroluminescence display (IELD). The detection method of the touch screen may be any method, such as a capacitance method, a resistive film method, a surface acoustic wave method, an ultrasonic method, an infrared method, an electromagnetic induction method, or a load detection method.

[0012] <Gas detection device 1> FIG. 2 is a schematic diagram showing an example of the configuration of gas detection device 1 according to an embodiment. FIG. 3 is a block diagram showing an example of the configuration of gas detection device 1. As described above, gas detection device 1 is installed in toilet 2, collects sample gas containing gas excreted from the feces of a subject, and can detect the type and concentration of a target gas contained in the sample gas. Gas detection device 1 can also transmit information indicating the type and concentration of the detected target gas to electronic device 3 as a detection result. As shown in FIGS. 2 and 3, gas detection device 1 includes housing 10, collection unit 21 (sample gas collection unit), storage pump 22, storage tank 25, sensor chamber 23 (gas detection unit), gas sensor group 24, chamber pump 26, discharge path 30, control unit 40, subject detection unit 50, communication unit 51, and memory unit 52.

[0013] (Housing 10) Housing 10 houses various components of gas detection apparatus 1. Housing 10 may be made of any material. For example, housing 10 may be made of a material such as metal or resin.

[0014] [Collection section 21] The sampling unit 21 is a tubular member that samples sample gas in the target space and supplies the sampled gas to the storage tank 25. The sampling unit 21 is exposed to the inside of the toilet bowl 2A and has an opening 211 that opens toward the interior of the toilet bowl 2A, and samples the sample gas in the toilet bowl 2A as the target space by the operation of a storage pump 22 (described below). The sampling unit 21 also has a sample flow path therein for flowing the sample gas. Here, the sample flow path refers to the flow path through which the sampled sample gas moves. The sample flow path connects the opening 211 with the sensor chamber 23.

[0015] [Storage Pump 22] The reservoir pump 22 is a pump located on the sample flow path. The reservoir pump 22 may operate under the control of a pump control unit 41 (described later). As an example, the reservoir pump 22 may be a pump that operates at a constant gas supply speed. The reservoir pump 22 may supply the sample gas from the collection unit 21 into the reservoir tank 25.

[0016] [Storage Tank 25] Reservoir 25 is located behind reservoir pump 22 on the sample flow path, and temporarily stores the sample gas collected by reservoir pump 22 from sampling unit 21. However, the function of reservoir 25 is not limited to temporarily storing the sample gas, and it may function as a part of the flow path that does not store the sample gas. Reservoir 25 may be formed in a bag shape from resin, or may be formed in a cylindrical or rectangular shape from metal.

[0017] [Sensor Chamber 23] The sensor chamber 23 is a chamber that houses the gas sensor group 24. The sensor chamber 23 is in communication with the storage tank 25. There is no particular limit to the number of gas sensors included in the gas sensor group 24 housed inside the sensor chamber 23. The gas sensor group 24 may include any number of gas sensors depending on the type and number of gases to be detected.

[0018] [Gas sensor group 24] The gas sensor group 24 includes a first gas sensor 24a and a second gas sensor 24b. Both the first gas sensor 24a and the second gas sensor 24b are gas sensors capable of detecting both the first and second detection gases. That is, both the first gas sensor 24a and the second gas sensor 24b detect the first and second detection gases as their detection target gases. Hereinafter, the detection signal output from the first gas sensor 24a will be referred to as the "first detection signal." Also, the detection signal output from the second gas sensor 24b will be referred to as the "second detection signal."

[0019] The gas sensor group 24 may be any group of sensors that output different detection signals depending on the concentration of the target gas. The following description will be given using, as an example, sensors that change the intensity of their detection signals depending on the concentration of the target gas, but this is not limiting. As an example, the sensors that make up the gas sensor group 24 can output, to the signal acquisition unit 42 of the control unit 40, detection signals with intensities that correspond to the concentrations of target gases that may be contained in the sample gas. As shown in FIG. 2 , the gas detection device 1 may include multiple gas sensors. Furthermore, the multiple gas sensors may each be capable of outputting detection signals that correspond to the concentrations of different types of target gases. This allows the gas detection device 1 to analyze the concentrations of multiple types of target gases.

[0020] The first detection gas and the second detection gas may both be gases containing sulfur atoms in their composition formula. A sensor that is sensitive to one type of gas containing sulfur atoms in its composition formula tends to also be sensitive to another type of gas containing sulfur atoms in its composition formula. For this reason, when a sample gas contains multiple types of target gases containing sulfur atoms in their composition formula, it is difficult to detect the concentration of any of the multiple target gases using a single gas sensor. With the gas detection device 1, instead of detecting the individual concentrations of multiple target gases containing sulfur atoms in their composition formula, the concentrations can be accurately estimated based on the first detection signal and the second detection signal, as described below.

[0021] Specifically, the first detection gas may be hydrogen sulfide. The second detection gas may be methyl mercaptan. Hydrogen sulfide and methyl mercaptan are gas species whose individual concentrations are particularly difficult to detect using a single gas sensor. Instead of detecting the individual concentrations of hydrogen sulfide and methyl mercaptan, gas detection device 1 can accurately estimate their concentrations based on the first detection signal and the second detection signal, as described below. However, the first detection gas and the second detection gas may also be gases other than hydrogen sulfide and methyl mercaptan that contain sulfur atoms in their composition formulas.

[0022] Furthermore, the first and second detection gases are not limited to gases containing sulfur atoms in their composition formula. For example, the first and second detection gases may both contain nitrogen atoms. Even when the sample gas contains multiple types of target gases containing nitrogen atoms in their composition formula, it is difficult to detect the concentration of any of the multiple target gases using a single gas sensor. With the gas detection device 1, instead of detecting the individual concentrations of multiple target gases containing nitrogen atoms in their composition formula, the concentrations can be accurately estimated based on the first and second detection signals, as described below.

[0023] FIG. 4 is a graph showing an example of fluctuations in the first detection signal output from the first gas sensor 24a due to hydrogen sulfide and methyl mercaptan. In FIG. 4, the horizontal axis represents time, and the vertical axis represents the first detection signal (voltage). In FIG. 4, reference numeral 401 represents a graph showing an example of fluctuations in the first detection signal due to hydrogen sulfide at a concentration of 0.3 ppm. In FIG. 4, reference numeral 402 represents a graph showing an example of fluctuations in the first detection signal due to methyl mercaptan at a concentration of 0.3 ppm. Period T1 in FIG. 4 is a period during which hydrogen sulfide or methyl mercaptan was supplied to the first gas sensor 24a. Period T2 in FIG. 4 is a period during which the supply of hydrogen sulfide or methyl mercaptan to the first gas sensor 24a was stopped and the hydrogen sulfide or methyl mercaptan that had been supplied up to that point was removed using, for example, external air or nitrogen.

[0024] As indicated by reference numeral 401 in Fig. 4, the first detection signal shows clear fluctuations due to hydrogen sulfide between periods T1 and T2. On the other hand, as indicated by reference numeral 402 in Fig. 4, the first detection signal shows slight fluctuations due to methyl mercaptan between periods T1 and T2, but these fluctuations are small compared to the fluctuations due to hydrogen sulfide. In other words, the detection sensitivity of the first gas sensor 24a to hydrogen sulfide is greater than the detection sensitivity of the first gas sensor 24a to methyl mercaptan.

[0025] FIG. 5 is a graph showing an example of fluctuations in the second detection signal output from the second gas sensor 24b due to hydrogen sulfide and methyl mercaptan. In FIG. 5, the horizontal axis represents time, and the vertical axis represents the second detection signal (voltage). In FIG. 5, reference numeral 501 represents a graph showing an example of fluctuations in the second detection signal due to hydrogen sulfide at a concentration of 0.3 ppm. In FIG. 5, reference numeral 502 represents a graph showing an example of fluctuations in the second detection signal due to methyl mercaptan at a concentration of 0.3 ppm. Period T3 in FIG. 5 is a period during which hydrogen sulfide or methyl mercaptan was supplied to the second gas sensor 24b. Period T4 in FIG. 5 is a period during which the supply of hydrogen sulfide or methyl mercaptan to the first gas sensor 24a was stopped and the hydrogen sulfide or methyl mercaptan that had been supplied up to that point was removed using, for example, external air or nitrogen.

[0026] As indicated by reference numeral 502 in Fig. 5, the second detection signal shows clear fluctuations due to methyl mercaptan between periods T3 and T4. On the other hand, as indicated by reference numeral 501 in Fig. 5, the second detection signal shows slight fluctuations due to hydrogen sulfide between periods T3 and T4, but these fluctuations are small compared to the fluctuations due to methyl mercaptan. In other words, the detection sensitivity of the second gas sensor 24b to methyl mercaptan is greater than the detection sensitivity of the second gas sensor 24b to hydrogen sulfide.

[0027] 4 and 5, the relative relationship between the detection sensitivity to hydrogen sulfide and the detection sensitivity to methyl mercaptan of the first gas sensor 24a and the second gas sensor 24b may be different. Specifically, when the concentrations of hydrogen sulfide and methyl mercaptan are equal, the ratio of the intensity of the first detection signal attributable to methyl mercaptan to the intensity of the first detection signal attributable to hydrogen sulfide may be smaller than the ratio of the intensity of the second detection signal attributable to methyl mercaptan to the intensity of the second detection signal attributable to hydrogen sulfide. By including such a first gas sensor 24a and second gas sensor 24b in the gas sensor group 24, the concentrations of hydrogen sulfide and methyl mercaptan can be estimated with high accuracy, as described below.

[0028] [Chamber Pump 26] The chamber pump 26 is a pump that introduces the sample gas from the reservoir tank 25 into the sensor chamber 23. The chamber pump 26 may operate under the control of a pump control unit 41 (described later). The chamber pump 26 may be, for example, a pump that operates at a constant gas supply speed. The discharge rate of the chamber pump 26 may be set to be smaller than the discharge rate of the reservoir pump 22.

[0029] (Exhaust channel 30) Discharge path 30 may be formed of a tubular member such as a resin tube or metal or glass piping. Discharge path 30 connects sensor chamber 23 to the outside of housing 10. Chamber pump 26 may be provided midway along discharge path 30. By operation of chamber pump 26, discharge path 30 discharges exhaust gas from sensor chamber 23 to the outside of gas detection device 1. A portion of discharge path 30 may be exposed to the outside of toilet bowl 2A, as shown in FIG. 1 .

[0030] (control unit 40) Control unit 40 controls the operation of each unit of gas detection device 1 and estimates the concentration of the detection target gas contained in the sample gas. As shown in Fig. 3, control unit 40 includes a pump control unit 41, a signal acquisition unit 42, and an estimation unit 43.

[0031] [Pump control unit 41] Pump control unit 41 controls the operation of storage pump 22 and chamber pump 26. Specifically, pump control unit 41 operates storage pump 22 and chamber pump 26 in accordance with the detection result of subject detection unit 50 (described below), and stops them after a predetermined time has elapsed. As a result, sample gas in toilet bowl 2A is sucked from sampling unit 21 and supplied into sensor chamber 23 via storage tank 25.

[0032] [Signal Acquisition Unit 42] The signal acquiring unit 42 acquires a detection signal corresponding to the type and concentration of the target gas contained in the sample gas from each gas sensor included in the gas sensor group 24. Specifically, the signal acquiring unit 42 may acquire the detection signal output from each gas sensor included in the gas sensor group 24 when the pump control unit 41 stops operating the storage pump 22 and the chamber pump 26.

[0033] [Estimation part 43] The estimation unit 43 estimates the type and concentration of the target gas contained in the sample gas based on the detection signals acquired by the signal acquisition unit 42 from each gas sensor included in the gas sensor group 24. The detection signals acquired from each gas sensor are the detection signals output from the gas sensors. The estimation unit 43 may estimate the concentrations of the first and second target gases based on the first and second detection signals output from the first and second gas sensors 24a and 24b. As described above, the first and second gas sensors 24a and 24b are both capable of detecting both the first and second target gases. Therefore, the combination of the concentrations of the first and second target gases cannot be uniquely estimated based on only either the first or second detection signal. As described above, the first and second gas sensors 24a and 24b have different relative detection sensitivities for the first and second target gases. Therefore, the estimation unit 43 can uniquely estimate a combination of the concentration of the first detection gas and the concentration of the second detection gas that matches both the first detection signal and the second detection signal.

[0034] 3, estimation unit 43 may be provided in control unit 40 of gas detection apparatus 1. Alternatively, estimation unit 43 may not be provided in control unit 40, but may be provided on a cloud connected to gas detection apparatus 1 via a network. When estimation unit 43 is provided on the cloud, signal acquisition unit 42 may transmit detection signals acquired from each gas sensor included in gas sensor group 24 to the cloud via the network. Estimation unit 43 on the cloud may estimate the type and concentration of the target gas based on the detection signals transmitted from signal acquisition unit 42.

[0035] The estimation unit 43 may estimate the concentrations of the first and second detectable gases contained in the sample gas using a concentration estimation model created from the first and second detection signals for multiple types of teacher gases. The teacher gas is a sample gas containing the first and second detectable gases, the concentrations of which are known. The concentration estimation model may be created by machine learning using a pair of the first and second detection signals for the teacher gas and the concentrations of the first and second detectable gases contained in the teacher gas. The estimation unit 43 can easily estimate the concentrations of the first and second detectable gases by using such a concentration estimation model.

[0036] (Target person detection unit 50) The subject detection unit 50 may be configured to include at least one of an image camera, a personal identification switch, an infrared sensor, a pressure sensor, etc. (not shown). The subject detection unit 50 outputs the detection result to the control unit 40.

[0037] For example, if the subject detection unit 50 is configured to include an infrared sensor, it can detect that the subject has entered the toilet room by detecting the reflected light from the object of infrared light irradiated by the infrared sensor. The subject detection unit 50 outputs a signal indicating that the subject has entered the toilet room to the control unit 40 as a detection result.

[0038] For example, if the subject detection unit 50 is configured to include a pressure sensor, it can detect that the subject has sat on the toilet seat 2B by detecting an increase in pressure on the toilet seat 2B shown in Fig. 1. As a detection result, the subject detection unit 50 outputs a signal to the control unit 40 indicating that the subject has sat on the toilet seat 2B.

[0039] For example, if the subject detection unit 50 is configured to include a pressure sensor, it can detect that the subject has stood up from the toilet seat 2B by detecting a decrease in pressure on the toilet seat 2B shown in Fig. 1. As a detection result, the subject detection unit 50 outputs a signal indicating that the subject has stood up from the toilet seat 2B to the control unit 40.

[0040] For example, if the subject detection unit 50 is configured to include an image camera, a personal identification switch, etc., it collects data such as facial images, sitting height, and weight. The subject detection unit 50 identifies and detects individuals from the collected data. The subject detection unit 50 outputs a signal indicating the identified individual to the control unit 40 as a detection result.

[0041] For example, if the subject detection unit 50 is configured to include a personal identification switch or the like, it identifies (detects) an individual based on the operation of the personal identification switch. In this case, personal information may be registered (stored) in advance in the storage unit 52. The subject detection unit 50 outputs a signal indicating the identified individual to the control unit 40 as the detection result.

[0042] The subject detection unit 50 may also detect that the subject has defecated. The subject detection unit 50 outputs a signal indicating that the subject has defecated to the control unit 40 as a detection result.

[0043] (Communications Department 51) The communication unit 51 communicates with the electronic device 3, which indicates the analysis result of the target gas by the control unit 40 to the subject, for example, by displaying it on the display unit 3A or by voice. The communication unit 51 may be capable of communicating with an external server. The communication method used in the communication between the communication unit 51 and the electronic device 3 and the external server may be a short-range wireless communication standard, a wireless communication standard connecting to a mobile phone network, or a wired communication standard. The short-range wireless communication standard may include, for example, Wi-Fi (registered trademark), Bluetooth (registered trademark), infrared, and NFC (Near Field Communication). The wireless communication standard connecting to a mobile phone network may include, for example, LTE (Long Term Evolution) or a fourth-generation or higher mobile communication system. The communication method used in the communication between the communication unit 51 and the electronic device 3 and the external server may be, for example, a communication standard such as LPWA (Low Power Wide Area) or LPWAN (Low Power Wide Area Network).

[0044] (Storage unit 52) Storage unit 52 is configured with, for example, a semiconductor memory or a magnetic memory. Storage unit 52 stores various types of information and programs for operating gas detection device 1. Storage unit 52 may function as a work memory. Storage unit 52 may also store, for example, a concentration estimation model used by estimation unit 43 to estimate the concentrations of the first detection gas and the second detection gas.

[0045] <Effects of Gas Detection Device 1> Conventionally, depending on the type of gas to be detected, it has not been possible to accurately measure the concentration using a single sensor. In response to this, gas detection device 1 may include sampling unit 21, storage pump 22, storage tank 25, sensor chamber 23, gas sensor group 24, chamber pump 26, and control unit 40. In particular, gas sensor group 24 may include first gas sensor 24a and second gas sensor 24b. Furthermore, control unit 40 may include estimation unit 43.

[0046] According to the above-described configuration, in the gas detection device 1, the concentration of the target gas contained in the sample gas is detected by the gas sensor group 24, which includes the first gas sensor 24a and the second gas sensor 24b. Both the first gas sensor 24a and the second gas sensor 24b may be gas sensors capable of detecting both the first and second target gases. The estimation unit 43 estimates the concentrations of the first and second target gases based on the first detection signal output by the first gas sensor 24a and the second detection signal output by the second gas sensor 24b. This allows the gas detection device 1 to estimate with high accuracy the concentration of gases whose concentrations are difficult to accurately measure using a single sensor.

[0047] [Embodiment 2] Other embodiments of the present disclosure will be described below. For convenience of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0048] In the gas detection device 1, the first gas sensor 24a and the second gas sensor 24b may both be electrochemical sensors. By using electrochemical sensors as the first gas sensor 24a and the second gas sensor 24b, the concentrations of the first and second detection gases described above can be detected with high sensitivity.

[0049] In the gas detection device 1, the first gas sensor 24a and the second gas sensor 24b are not limited to electrochemical sensors, and may be, for example, a semiconductor sensor, a quartz crystal microbalance (QCM) sensor, a complementary metal oxide semiconductor (CMOS) sensor, a sensitive film sensor, an optical sensor, or a photoacoustic sensor. Sensitive film sensors may include sensitive film stress sensors or sensitive film resonance sensors. The gas sensor group 24 may include multiple types of sensors. The first gas sensor 24a and the second gas sensor 24b may be selected depending on the first and second detection target gases to be detected.

[0050] 6 is a partial cross-sectional view showing an example of the configuration of the first gas sensor 24a included in the gas sensor group 24. The second gas sensor 24b may have the same configuration as the first gas sensor 24a, and is therefore not shown. As shown in FIG. 6, the first gas sensor 24a may include a case 241, a first electrode 244, a second electrode 245, and an electrode pin 246.

[0051] The case 241 is a housing that houses a first electrode 244 (electrode), a second electrode 245 (electrode), and an electrolyte. A reference electrode may be provided between the first electrode 244 and the second electrode 245. The case 241 is formed with an air vent 242 for introducing sample gas therein. The air vent 242 may be provided with a pre-filter 243 for reducing the intrusion of foreign matter such as dust into the case 241.

[0052] First electrode 244 and second electrode 245 may be disposed, for example, at positions facing each other inside case 241. First electrode 244 may be disposed, for example, on the side of vent hole 242. In that case, second electrode 245 may be disposed, for example, on the side of the surface of case 241 that faces first electrode 244. Furthermore, when first electrode 244 and second electrode 245 are adjacent to each other, a nonwoven fabric may be disposed between them.

[0053] In the first gas sensor 24a, the first electrode 244 and the second electrode 245 are electrically connected to each other via an electrolyte. The first electrode 244, the second electrode 245, and the electrolyte constitute an electrode unit that outputs a signal corresponding to the concentration of the target gas contained in the sample gas. The first electrode 244 and the second electrode 245 may be electrodes whose main component is carbon. The electrolyte may be, for example, sulfuric acid-based, but is not limited to this.

[0054] When sample gas introduced into case 241 through vent hole 242 comes into contact with the electrolyte, a portion of the sample gas dissolves in the electrolyte, causing a change in the resistance between first electrode 244 and second electrode 245. The degree of change in resistance varies depending on the type and concentration of gas contained in the sample gas. As a result, the voltage between first electrode 244 and second electrode 245 changes depending on the type and concentration of gas contained in the sample gas. This change in voltage becomes a signal indicating the type and concentration of gas contained in the sample gas.

[0055] The electrode pin 246 is a pin for extracting signals output from the first electrode 244 and the second electrode 245 to the outside. The first gas sensor 24a may include an electrode pin 246 connected to the first electrode 244 and an electrode pin 246 connected to the second electrode 245. The electrode pin 246 may be made of, for example, platinum, but is not limited to this.

[0056] [Embodiment 3] Further embodiments of the present disclosure are described below.

[0057] Fig. 7 is a schematic diagram showing an example of the configuration of a gas detection apparatus 1A according to embodiment 3. As shown in Fig. 7, gas detection apparatus 1A differs from gas detection apparatus 1 only in that gas sensor group 24 further includes a third gas sensor 24c.

[0058] The third gas sensor 24c is a gas sensor capable of detecting the first and second detectable gases. The detection sensitivity of the third gas sensor 24c for the first detectable gas may be different from the detection sensitivity of the first gas sensor 24a for the first detectable gas and the detection sensitivity of the second gas sensor 24b for the first detectable gas. By including the third gas sensor 24c, the gas detection device 1A can obtain three different detection signals for the first and second detectable gases. Therefore, the concentrations of the first and second detectable gases can be estimated with higher accuracy.

[0059] [Embodiment 4] Further embodiments of the present disclosure are described below.

[0060] In the fourth embodiment, the gas species of the first and second detection gases differ from those in the first embodiment. In the fourth embodiment, the first detection gas may be hydrogen sulfide or methyl mercaptan. The second detection gas may be hydrogen, water, ammonia, or alcohol.

[0061] The second detectable gas described above is a gas that causes noise or interferes with the output signal from the gas sensor that detects the first detectable gas described above. That is, the concentration of the second detectable gas affects the detection signal from the gas sensor that detects the first detectable gas. For this reason, in an environment where the second detectable gas described above is present, it is difficult to detect the concentration of the first detectable gas using a single gas sensor.

[0062] In the fourth embodiment, when the concentrations of the first and second detectable gases are equal to each other, the ratio of the intensity of the second detection signal caused by the second detectable gas to the intensity of the second detection signal caused by the first detectable gas may be greater than 1. When the concentrations of the first and second detectable gases are substantially equal to each other, the ratio of the intensity of the second detection signal caused by the second detectable gas to the intensity of the second detection signal caused by the first detectable gas may be greater than 10. That is, the second gas sensor 24b may be a gas sensor that primarily detects the second detectable gas. By including such a second gas sensor 24b in the gas detection device 1, the estimation unit 43 can accurately estimate the concentration of the second detectable gas based on the second detection signal. That is, the estimation unit 43 can also accurately estimate the magnitude of the effect of the concentration of the second detectable gas on the first detection signal. Therefore, the estimation unit 43 can accurately estimate the concentration of the first detectable gas based on the first detection signal.

[0063] In the fourth embodiment, the second detection signal output from the second gas sensor 24b has little effect on the estimation of the concentration of the first detection target gas, and generally, such a second detection signal is not used as an explanatory variable in the concentration estimation model for the first detection target gas.

[0064] However, in the machine learning for creating a concentration estimation model for estimation by estimation unit 43, the second detection signal may also be used as an explanatory variable in the concentration estimation model for the first detectable gas. By using the second detection signal as an explanatory variable in the concentration estimation model for the first detectable gas, the effect of the concentration of the second detectable gas on the first detection signal can be reduced, and the concentration of the first detectable gas can be estimated with high accuracy.

[0065] [Embodiment 5] Further embodiments of the present disclosure are described below.

[0066] Fig. 8 is a schematic diagram showing an example of the configuration of gas detection apparatus 1B according to embodiment 5. As shown in Fig. 8, gas detection apparatus 1B differs from gas detection apparatus 1 in that sensor chamber 23 is located downstream of chamber pump 26. Gas detection apparatus 1B like this can also estimate with high accuracy the concentration of gases whose concentrations are difficult to measure accurately using a single sensor.

[0067] [Software implementation example] The functions of the gas detection devices 1, 1A, 1B (hereinafter referred to as "devices") can be realized by a program that causes a computer to function as the device, and a program that causes a computer to function as each control block of the device (particularly each part included in the control unit 40).

[0068] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The control device and storage device execute the program, thereby realizing the functions described in each of the above embodiments.

[0069] The program may be non-transitory and may be recorded on one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be supplied to the device via any wired or wireless transmission medium.

[0070] In addition, some or all of the functions of each of the control blocks can be realized by logic circuits. For example, integrated circuits in which logic circuits that function as each of the control blocks are formed are also included in the scope of the present disclosure. In addition, the functions of each of the control blocks can also be realized by, for example, a quantum computer.

[0071] Furthermore, each process described in each of the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI ​​may run on the control device or on another device (for example, an edge computer or a cloud server).

[0072] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0073] 1, 1A, 1B Gas detection device 21 Sampling section (sample gas sampling section) 23 Sensor chamber (gas detection part) 24a First gas sensor 24b Second gas sensor 24c Third gas sensor 244 1st electrode (electrode) 245 Second electrode (electrode) 43 Estimation part

Claims

1. a sample gas collecting unit that collects a sample gas containing the first detection target gas and the second detection target gas; a gas detection unit including a plurality of gas sensors, including a first gas sensor and a second gas sensor, capable of detecting both the first detection target gas and the second detection target gas contained in the sample gas; a storage tank for temporarily storing the sample gas; a reservoir pump that supplies the sample gas from the sample gas collection unit to the reservoir tank; a chamber pump that introduces the sample gas from the reservoir to the gas detection unit, the first gas sensor and the second gas sensor have different relative detection sensitivities to the first detection gas and the second detection gas, the reservoir pump is located upstream of the gas detection unit, and the chamber pump is located downstream of the gas detection unit; A gas detection device, wherein the discharge rate of the chamber pump is set to be smaller than the discharge rate of the storage pump.

2. a ratio of an intensity of the first detection signal caused by the second detection gas to an intensity of the first detection signal output from the first gas sensor caused by the first detection gas, 2. The gas detection device according to claim 1, wherein the intensity of the second detection signal output from the second gas sensor due to the first detection gas is smaller than a ratio of the intensity of the second detection signal due to the second detection gas to the intensity of the second detection signal output from the second gas sensor due to the first detection gas.

3. 3. The gas detection device according to claim 1, wherein the first gas sensor and the second gas sensor are both electrochemical sensors.

4. 3. The gas detection device according to claim 1, wherein the first detection gas and the second detection gas are both gases containing sulfur atoms or both gases containing nitrogen atoms in their composition formulas.

5. the first detection gas is hydrogen sulfide, 5. The gas detection device according to claim 4, wherein the second detection target gas is methyl mercaptan.

6. the gas detection unit further includes a third gas sensor capable of detecting the first detection target gas and the second detection target gas; 4. The gas detection device according to claim 3, wherein the detection sensitivity of the third gas sensor to the first detection target gas is different from both the detection sensitivity of the first gas sensor to the first detection target gas and the detection sensitivity of the second gas sensor to the first detection target gas.

7. the first detection gas is hydrogen sulfide or methyl mercaptan, the second detection gas is hydrogen, water, ammonia, or alcohol; 3. The gas detection device according to claim 1, wherein a ratio of an intensity of the second detection signal output from the second gas sensor due to the first detection gas to an intensity of the second detection signal due to the second detection gas is greater than 1.

8. a sample gas collecting unit that collects a sample gas containing the first detection target gas and the second detection target gas; a gas detection unit including a plurality of gas sensors, including a first gas sensor and a second gas sensor, capable of detecting both the first detection target gas and the second detection target gas contained in the sample gas; a storage tank for temporarily storing the sample gas; a reservoir pump that supplies the sample gas from the sample gas collection unit to the reservoir tank; a chamber pump that introduces the sample gas from the reservoir to the gas detection unit, the first gas sensor and the second gas sensor have different relative detection sensitivities to the first detection gas and the second detection gas, the reservoir pump is located upstream of the gas detection unit, and the chamber pump is located downstream of the gas detection unit; a gas detection device in which the discharge amount of the chamber pump is set smaller than the discharge amount of the storage pump; an estimation unit that estimates the concentrations of the first detection gas and the second detection gas based on a first detection signal output from the first gas sensor and a second detection signal output from the second gas sensor.

9. 9. The gas detection system according to claim 8, wherein the estimation unit estimates the concentrations of the first detectable gas and the second detectable gas contained in the sample gas using a concentration estimation model created from the first detection signal and the second detection signal for a plurality of types of teacher gases including the first detectable gas and the second detectable gas, the concentrations of which are known.

10. A gas detection device as described in claim 1 or 2, wherein the chamber pump is a pump that operates at a constant air supply rate.

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