Odor measurement device

Abstract

The purpose of the present invention is to output stable odor component detection results. An odor measurement device (100) adjusts the temperature of a first gas traversing a first target section (A1) and the temperature of a second gas traversing a second target section (A2), and is configured so that the difference between a first traversal time during which the first gas traverses the first target section (A1) and a second traversal time during which the second gas traverses the second target section (A2) is a prescribed value or less.

Description

Odor measuring device

[0001] The present invention relates to an odor measuring device.

[0002] In recent years, odor measurement devices have been developed that detect odor components contained in a gas to be measured. These odor measurement devices include an odor sensor element for detecting odor components, and detect the odor components contained in the target gas based on a measurement signal output from the odor sensor element.

[0003] For example, Patent Document 1 describes a gas detection sensor device that detects the concentration of a specific gas contained in the atmosphere. It describes that the gas detection sensor device is equipped with a gas sensor that can detect odors (bad odors), and thus can detect fluctuations in the concentration of gas that causes bad odors.

[0004] Japanese Patent Application Publication No. 2019-120672

[0005] Before measuring an odor, an odor measuring device uses a gas, such as outside air, to remove any remaining target gas from the chamber housing the odor sensor element. However, odor sensor elements have temperature characteristics and are easily affected by the temperature of the gas. Therefore, if there is a temperature difference between the temperature of the gas that passed through before measurement and the temperature of the target gas, this temperature difference can cause variations in the measurement signal output from the odor sensor element. As a result, there is a risk that the detection results of odor components by the odor measuring device will be unstable.

[0006] One aspect of the present invention aims to output stable detection results of odor components.

[0007] In order to solve the above-mentioned problems, the measurement device according to the present invention includes an odor measuring unit that measures the odor of a first gas that has arrived from a first supply source; a first flow path through which the first gas passes before reaching the odor measuring unit, the first flow path including, in order from the first supply source toward the odor measuring unit, a first supply unit connected to the first supply source, a first switching valve, a first intermediate unit, and a second switching valve; and a flow path through which a second gas, which is a gas different from the first gas and arrives at the odor measuring unit from a second supply source different from the first supply source and is used to remove the first gas from the odor measuring unit, passes before reaching the odor measuring unit. and a second flow path including, in order from the second supply source toward the odor measuring unit, a second supply unit connected to the second supply source, a third switching valve, a second intermediate unit, and a fourth switching valve, wherein a first target section which is at least a portion of the section between the first switching valve and the odor measuring unit of the first flow path, and a second target section which is at least a portion of the section between the third switching valve and the odor measuring unit of the second flow path are temperature-controlled, and are configured so that the difference between the first transit time for the first gas to pass through the first target section and the second transit time for the second gas to pass through the second target section is equal to or less than a predetermined value.

[0008] According to one aspect of the present invention, stable detection results of odor components can be output.

[0009] Fig. 1 is a schematic diagram showing an example of the configuration of an odor measurement device according to one embodiment of the present invention. Fig. 2 is a functional block diagram showing an example of the configuration of an odor measurement device according to one embodiment of the present invention. Fig. 3 is a top view showing an example of the configuration of an odor sensor element. Fig. 4 is a flowchart showing an example of a control method by a control unit of an odor measurement device according to one embodiment of the present invention. Fig. 5 is a schematic diagram showing an example of the configuration of an odor measurement device according to one embodiment of the present invention.

[0010] One embodiment of the present invention will be described below, but the present invention is not limited thereto. Furthermore, unless otherwise specified in this specification, the expression "A to B" representing a range of numerical values ​​means "A or more and B or less."

[0011] [Embodiment 1] (Outline of odor measurement device 100) First, an outline of an odor measurement device 100 according to one embodiment of the present invention will be described using Fig. 1. Fig. 1 is a schematic diagram showing an example of the configuration of an odor measurement device 100 according to one embodiment of the present invention. The odor measurement device 100 is a device that detects odor components contained in a gas to be measured. As shown in Fig. 1, the odor measurement device 100 includes a first flow path 10, a second flow path 20, an odor measurement unit 30, a flow control unit 60, and a temperature adjustment unit 65.

[0012] The first flow path 10 is a flow path connectable to a first supply source 40 that contains a first gas to be measured. The first supply source 40 is, for example, a sampling bag, a vial, a medium bottle, or a syringe. The first flow path 10 is a flow path through which the first gas passes from the first supply source 40 to reach the odor measuring unit 30. That is, the first gas supplied from the first supply source 40 passes through the first flow path 10 and reaches the odor measuring unit 30. The first flow path 10 includes, in order from the first supply source 40 to the odor measuring unit 30, a first supply unit 11, a first switching valve 12, a first intermediate unit 13, a second switching valve 14, and a common unit 50.

[0013] The first supply unit 11 and the first intermediate unit 13 are each a flow path, such as a pipe, through which the first gas passes. The first supply unit 11 is connectable to a first supply source 40. The first intermediate unit 13 is connected to the first supply unit 11 via a first switching valve 12 and to the common unit 50 via a second switching valve 14. That is, the first intermediate unit 13 is a flow path located between the first switching valve 12 and the second switching valve 14. The first intermediate unit 13 has a first loop unit 131 having a loop shape. Note that the first intermediate unit 13 does not necessarily have to have the first loop unit 131.

[0014] The first flow path 10 further includes a pump 15 and a gas suction unit 16. The pump 15 is for supplying the first gas contained in the first supply source 40 to the first flow path 10. The gas suction unit 16 is connected to the pump 15, and is connected to the first intermediate unit 13 via the second switching valve 14. The gas suction unit 16 is, for example, a pipe.

[0015] The first switching valve 12 is a valve that can switch between communicating between the first supply unit 11 and the first intermediate section 13 and communicating between the second supply unit 21 and the first intermediate section 13. More specifically, when communicating between the second supply unit 21 and the first intermediate section 13, the first switching valve 12 communicates between the first connection unit 55 and the first intermediate section 13. The first switching valve 12 is, for example, a multi-valve such as a three-way solenoid valve, a three-way valve, an eight-way solenoid valve, or a sixteen-way solenoid valve. The first connection unit 55 is a flow path provided between the first switching valve 12 and the third switching valve 22. The length of the first connection unit 55 is approximately 3 / 1000 to 1 / 20 of the length of the first intermediate section 13. For example, the length of the first connection unit 55 may be 1 / 200 or 1 / 100 of the length of the first intermediate section 13. The length of the first connecting portion 55 is a length of the flow path that does not affect the temperature of the second gas passing through the first connecting portion 55. The length of the flow path that does not affect the temperature of the second gas passing through the first connecting portion 55 is, for example, 5 cm. For example, the length of the first intermediate portion 13 may be 5 m or 10 m. The length of the flow path that does not affect the temperature of the second gas passing through the first connecting portion 55 may be determined according to the thickness of the first connecting portion 55. That is, if the thickness of the first connecting portion 55 is thin, the length of the flow path needs to be short, and if the thickness of the first connecting portion 55 is thick, the length of the flow path may be long.

[0016] The second switching valve 14 is a valve that can switch whether or not the first intermediate section 13 and the common section 50 are in communication with each other. More specifically, when the second switching valve 14 is in a state where the first intermediate section 13 is in communication with the common section 50, the second switching valve 14 connects the first intermediate section 13 to the second connecting section 56. The second connecting section 56 is a flow path provided between the second switching valve 14 and the fourth switching valve 24. The second connecting section 56 has a length that is approximately 3 / 1000 to 1 / 20 of the length of the first intermediate section 13. For example, the second connecting section 56 may have a length that is 1 / 200 or 1 / 100 of the length of the first intermediate section 13. The second connecting section 56 has a flow path length that does not affect the temperature of the first gas passing through the second connecting section 56. The flow path length that does not affect the temperature of the first gas passing through the second connecting section 56 is, for example, 5 cm. For example, the length of the first intermediate section 13 may be 5 m or 10 m. In this embodiment, the second switching valve 14 connects the first intermediate section 13 to the gas suction section 16 when the first intermediate section 13 is not connected to the common section 50. The second switching valve 14 is, for example, a multi-valve such as a three-way solenoid valve, a three-way valve, an eight-way solenoid valve, or a sixteen-way solenoid valve.

[0017] The second flow path 20 is a flow path connectable to a second supply source 45 that contains a second gas for removing the first gas from the odor measurement unit 30. The second gas is, for example, air or nitrogen, and the second supply source 45 may include, for example, a gas cooler, a membrane dehumidifier, a filter, or a desiccant (e.g., silica gel, calcium chloride, zeolite, etc.). The air used as the second gas may be the air in a room in which the odor measurement device 100 is installed. In this case, the second supply source 45 may be the space in the room in which the odor measurement device 100 is installed. The second flow path 20 is a flow path through which the second gas passes from the second supply source 45 to reach the odor measurement unit 30. That is, when the first gas is removed from the odor measurement unit 30 using the second gas, the second gas supplied from the second supply source passes through the second flow path 20 and reaches the odor measurement unit 30. The second flow path 20 includes, in order from the second supply source 45 toward the odor measuring unit 30, a second supply unit 21, a third switching valve 22, a second intermediate unit 23, a fourth switching valve 24, and a common unit 50.

[0018] The second supply unit 21 and the second intermediate unit 23 are each a flow path, such as a pipe, through which the second gas passes. The second supply unit 21 is connectable to a second supply source 45. The second intermediate unit 23 is connected to the second supply unit 21 via a third switching valve 22 and to the common unit 50 via a fourth switching valve 24. That is, the second intermediate unit 23 is a flow path located between the third switching valve 22 and the fourth switching valve 24. The second intermediate unit 23 has a second loop unit 231 having a loop shape. Note that the second intermediate unit 23 does not necessarily have to have the second loop unit 231.

[0019] The third switching valve 22 is a valve that can switch whether to connect the second supply unit 21 and the second intermediate unit 23 to each other. In the present embodiment, the third switching valve 22 is a valve that can switch whether to connect the second supply unit 21 and the second intermediate unit 23 to each other or to connect the second supply unit 21 and the first intermediate unit 13 to each other. More specifically, the third switching valve 22 connects the second supply unit 21 and the first connection unit 55 to each other when the second supply unit 21 and the second intermediate unit 23 are not connected to each other. The third switching valve 22 is a multi-valve, such as a three-way solenoid valve, a three-way valve, an eight-way solenoid valve, or a sixteen-way solenoid valve.

[0020] The fourth switching valve 24 is a valve that can switch whether to connect the second intermediate section 23 to the common section 50. In the present embodiment, the fourth switching valve 24 is a valve that can switch whether to connect the second intermediate section 23 to the common section 50 or to connect the first intermediate section 13 to the common section 50. In the present embodiment, the fourth switching valve 24 connects the second connection section 56 to the common section 50 when the first intermediate section 13 is connected to the common section 50. The fourth switching valve 24 is, for example, a multi-valve such as a three-way solenoid valve, a three-way valve, an eight-way solenoid valve, or a sixteen-way solenoid valve.

[0021] The common part 50 is a flow path connected to the odor measuring part 30. The common part 50 is a flow path through which the first gas and the second gas can pass, and constitutes the first flow path 10 and the second flow path 20. The common part 50 is, for example, a pipe. The common part 50 has a third loop part 501 having a loop shape. Note that the common part 50 does not necessarily have to have the third loop part 501.

[0022] Furthermore, the odor measuring device 100 does not necessarily have to include the common section 50. In the case where the common section 50 is not included, the first flow path 10 and the second flow path 20 are each connected to the odor measuring section 30 via separate connection ports, and the second switching valve 14 switches whether or not the first intermediate section 13 and the odor measuring section 30 are connected to each other, and the fourth switching valve 24 switches whether or not the second intermediate section 23 and the odor measuring section 30 are connected to each other.

[0023] The flow rate control unit 60 is a unit that controls the flow rate of the second gas supplied from the second supply source 45. More specifically, the flow rate control unit 60 controls the flow rate of the second gas flowing from the second supply source 45 to the second supply unit 21. The flow rate control unit 60 is provided in the second supply unit 21. The flow rate control unit 60 is, for example, a mass flow controller or a needle valve.

[0024] The temperature adjustment unit 65 adjusts the temperatures of the flow paths and switching valves provided therein. The first switching valve 12, the first intermediate section 13, the second switching valve 14, the third switching valve 22, the second intermediate section 23, the fourth switching valve 24, the common section 50, the first connecting section 55, the second connecting section 56, and the odor measuring unit 30 are provided inside the temperature adjustment unit 65. Air is contained inside the temperature adjustment unit 65. Note that the temperature adjustment unit 65 may also contain a liquid. The temperature adjustment unit 65 is, for example, a constant temperature bath or a constant temperature and humidity bath. Note that it is sufficient that at least the first target section A1 of the first flow path 10 and the second target section A2 of the second flow path 20 are provided inside the temperature adjustment unit 65. The odor measuring unit 30 does not necessarily have to be provided inside the temperature adjustment unit 65. The temperature inside the temperature adjustment unit 65 is controlled to, for example, 30°C to 60°C. The temperature inside the temperature control section 65 is preferably controlled to 35°C to 40°C.

[0025] In the odor measuring device 100, the first target section A1 of the first flow path 10 and the second target section A2 of the second flow path 20 are temperature-regulated. The first target section A1 is a section of the first flow path 10 between the first switching valve 12 and the odor measuring unit 30. The second target section A2 is a section of the second flow path 20 between the third switching valve 22 and the odor measuring unit 30. In other words, the odor measuring device 100 regulates the temperatures of the first gas and the second gas so that the temperatures of the first gas and the second gas reaching the odor measuring unit 30 are constant. Note that the first target section A1 may be at least a portion of the section between the first switching valve 12 and the odor measuring unit 30, and the second target section A2 is at least a portion of the section between the third switching valve 22 and the odor measuring unit 30.

[0026] In this embodiment, the first target section A1 of the first flow path 10 is the first intermediate section 13 and the common section 50, and the second target section A2 of the second flow path 20 is the second intermediate section 23 and the common section 50. It is desirable that the first target section A1 and the second target section A2 at least include the common section 50. By including a common section in the first target section A1 and the second target section A2, the temperatures of the first gas and the second gas are regulated in the common section 50 connected to the odor measurement unit 30. This allows the temperatures of the first gas and the second gas reaching the odor measurement unit 30 to be set to predetermined temperatures. The temperature of the first gas passing through the first connection section 55 may also be regulated.

[0027] It is preferable that the temperature of the odor measurement unit 30 is regulated, along with the temperature of the first target section A1 and the second target section A2. By regulating the temperature of the odor measurement unit 30, the temperature inside the odor measurement unit 30 can be set to a predetermined temperature. This reduces the temperature difference between the temperature of the first gas that has passed through the first target section A1 and the temperature inside the odor measurement unit 30, and the temperature difference between the temperature of the second gas that has passed through the second target section A2 and the temperature inside the odor measurement unit 30.

[0028] The temperature of the first gas passing through the first target section A1 and the second gas passing through the second target section A2 is controlled by the outside air surrounding the first target section A1 and the second target section A2. That is, the temperature of the first gas passing through the first target section A1 and the second gas passing through the second target section A2 is controlled by the gas inside the temperature control unit 65. Therefore, the temperature of the first gas and the second gas reaching the odor measuring unit 30 is controlled to a temperature close to the air temperature inside the temperature control unit 65 or a temperature slightly higher than the air temperature inside the temperature control unit 65. If the temperature control unit 65 is a thermostatic bath equipped with a heater, the gas inside the temperature control unit 65 is heated by the heater and agitated by a fan installed inside the temperature control unit 65. As a result, the air temperature inside the temperature control unit 65 is controlled to a set temperature and uniformized at that temperature. The air temperature inside the temperature control unit 65 may be set to, for example, 35°C to 40°C. The temperature inside the temperature adjustment unit 65 may be room temperature. The temperatures of the first target section A1 and the second target section A2 may be adjusted by a liquid stored inside the temperature adjustment unit 65.

[0029] Furthermore, the odor measuring device 100 is configured so that the difference between the first transit time for the first gas to pass through the first target section A1 and the second transit time for the second gas to pass through the second target section A2 is equal to or less than a predetermined value. The first transit time does not include the time during which the first gas is retained in the first target section A1, and the second transit time does not include the time during which the second gas is retained in the second target section A2. As described above, the second connection section 56 has a flow path length that does not affect the temperature of the first gas passing through the second connection section 56, so the transit time of the first gas passing through the second connection section 56 can be ignored. In other words, the first transit time does not include the transit time of the first gas passing through the second connection section 56. The first transit time and the second transit time are set appropriately depending on the flow path volumes, materials, etc. of the flow paths arranged in the first target section A1 of the first flow path 10 and the flow paths arranged in the second target section A2 of the second flow path 20.

[0030] In this embodiment, the flow path volume of the first target section A1 and the flow path volume of the second target section A2 are substantially the same. As described above, the second connecting section 56 has a flow path length that does not affect the temperature of the first gas passing through the second connecting section 56, so the flow path volume of the second connecting section 56 can be ignored. That is, the flow path cross-sectional area of ​​the first intermediate section 13 and the flow path cross-sectional area of ​​the second intermediate section 23 are substantially the same, and the length of the first intermediate section 13 and the length of the second intermediate section 23 are substantially the same. Here, in this specification, the flow path cross-sectional area refers to the cross-sectional area of ​​the flow path in a direction perpendicular to the gas flow direction. For each of the first intermediate section 13, the second intermediate section 23, and the common section 50, a pipe with an inner diameter of 1 / 16 inch is used, for example. The length of the common section 50 is, for example, 5 m. The flow path volume of each of the first intermediate section 13, the second intermediate section 23, and the common section 50 is, for example, 10 ml when a pipe with an inner diameter of 1 / 16 inch is used and the length is 5 m.

[0031] The first intermediate section 13, the second intermediate section 23, and the common section 50 preferably have the same thermal conductivity. Pipes made of the same material may be used for the first intermediate section 13, the second intermediate section 23, and the common section 50. Examples of materials for the first intermediate section 13, the second intermediate section 23, and the common section 50 include polytetrafluoroethylene (PTFE), tetrafluoroethylene (TFE), perfluoroalkoxyalkane (PFA), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP).

[0032] In this way, symmetry is provided between the flow path configuration of the first target section A1 of the first flow path 10 and the flow path configuration of the second target section A2 of the second flow path 20. Therefore, by controlling the flow rate of the first gas passing through the first target section A1 and the flow rate of the second gas passing through the second target section A2 to be substantially the same, it is possible to easily regulate the temperatures of the first gas and the second gas that reach the odor measuring unit 30. In this embodiment, the first intermediate section 13, the second intermediate section 23, and the common section 50 have the function of regulating the temperatures of the gases passing through them.

[0033] The first target section A1 and the second target section A2 may be provided with a thermal insulating material. This makes it easier to adjust the temperature of the first gas passing through the first target section A1 and the second gas passing through the second target section A2. Furthermore, if the temperature of the second gas is extremely lower than room temperature, a temperature adjustment chamber may be provided in the second flow path 20 to warm the temperature of the second gas from below room temperature to approximately room temperature.

[0034] (Odor Measuring Unit 30) Next, an overview of the odor measuring unit 30 employing the odor sensor element 31 will be described with reference to Fig. 2. Fig. 2 is a functional block diagram showing an example of the configuration of the odor measuring device 100. The odor measuring unit 30 measures the odor of the first gas arriving from the first supply source 40. The odor measuring unit 30 includes an odor sensor element 31 that detects odor substances, a power source 32 (power supply), and a clock 33 (timer).

[0035] The power supply 32 is a power source for supplying power to the odor sensor element 31. If the power supply 32 is a constant voltage power supply, the power supply 32 supplies a constant voltage to the odor sensor element 31 via lead wires. The voltage value supplied by the power supply 32, which is a constant voltage power supply, is 0.5 V to 10 V, for example, 2.5 V. If the power supply 32 is a constant current power supply, the power supply 32 supplies a constant current to the odor sensor element 31 via lead wires. The power supply 32, which is a constant current power supply, supplies a direct current of, for example, 0.1 mA.

[0036] The clock 33 measures the time. The clock 33 transmits the measured time to the control unit 70. The clock 33 may be a clock whose time is set by the user, or may be a radio-controlled clock. The clock 33 may be, for example, a clock built into a computer and capable of outputting time information. Note that the time transmitted to the control unit 70 is not limited to time information output by the clock 33, but may also be time information obtained from an FTP server by a computer connected to the FTP server.

[0037] The odor measuring unit 30 further includes a housing (not shown). The housing is a container having an internal space through which gas containing an odor substance can pass. The odor sensor element 31 is installed within the internal space of the housing. The volume of the internal space in which the odor sensor element 31 is installed is, for example, 0.07 ml. The volume of the internal space in which the odor sensor element 31 is installed can be, for example, 0.07 ml to 0.28 ml.

[0038] The odor measuring unit 30 outputs a measurement signal that indicates the change over time in the electrical conductivity of the odor sensor element 31 before and after an odor substance is adsorbed to the odor sensor element 31. This makes it possible to detect and identify various odor substances.

[0039] <Odor sensor element 31> Figure 3 is a top view showing an example of the configuration of the odor sensor element 31. The odor sensor element 31 includes an odorant receiving layer 315 containing a resin composition, a first metal wiring 313A, and a second metal wiring 313B. Note that, hereinafter, when there is no need to distinguish between the first metal wiring 313A and the second metal wiring 313B, they may be referred to as metal wiring 313.

[0040] The first metal wiring 313A and the second metal wiring 313B are metal wirings that function as electrodes for measuring changes in the electrical conductivity of the odorant receiving layer 315 (i.e., the resin composition). That is, the first metal wiring 313A and the second metal wiring 313B are spaced apart from each other, and the odorant receiving layer 315 is in contact with at least a portion of the first metal wiring and at least a portion of the second metal wiring. In one example, the first metal wiring 313A and the second metal wiring 313B are metal wirings that are not in direct contact with each other, and may be metal wirings that are approximately parallel to each other, as shown in FIG. 3.

[0041] 3, metal wiring 313 including first metal wiring 313A and second metal wiring 313B may be disposed on a substrate 311. Substrate 311 may be a substrate such as glass epoxy commonly used in electronic circuits. Metal wiring 313 may be metal wiring such as copper or gold. The thickness of each of first metal wiring 313A and second metal wiring 313B as viewed in a direction perpendicular to the surface of the substrate may be, for example, 10 μm to 2 mm.

[0042] The odorant receiving layer 315 may be in contact with at least a portion of the first metal wiring 313A and at least a portion of the second metal wiring 313B. The odorant receiving layer 315 may be arranged to fill the area between the first metal wiring 313A and the second metal wiring 313B, as shown in FIG.

[0043] If the electrical conductivity of the odorant receiving layer 315 (i.e., the electrical conductivity of the odor sensor element 31) is low, it is desirable that the distance between the first metal wiring 313A and the second metal wiring 313B be less than a predetermined distance (e.g., 500 μm).

[0044] The odorant receiving layer may contain a resin composition. The resin composition may contain a resin and may further contain one or more types selected from a surfactant and a filler (e.g., a conductive carbon material). In this specification, "odorant receiving layer" refers to a layer that adsorbs the odorant to be identified. The odorant receiving layer 315 is formed from the above-mentioned resin composition. The odorant receiving layer 315 may be provided as part of the odor sensor element 31. The electrical resistance value of this odorant receiving layer 315 changes in response to the adsorption of the odorant. In other words, the odor sensor element 31 is an odor detection device equipped with such an odorant receiving layer 315, and the odor measurement method of the odor sensor element 31 may be a chemiresistor type. Furthermore, the odor sensor element 31 is not limited to the above-mentioned chemiresistor type odor sensor element, and may include one or more types of odor sensor elements used in known odor sensors, etc.

[0045] When the odor sensor element 31 is a chemiresistor type containing a resin composition, the change in electrical conductivity over time differs between when odor substance A is adsorbed and when odor substance B, which is different from odor substance A, is adsorbed, making it possible to detect and distinguish various odor substances. The odor measurement unit 30, described below, includes multiple odor sensor elements 31 each having a substrate 311 on which a structure for detecting odor substances (metal wiring 313 and an odorant receiving layer 315) is provided. Each substrate 311 is provided with multiple sets each including multiple odorant receiving layers 315. Each of the multiple odor sensor elements 31 may be equipped with a constant-voltage power supply and a voltmeter. In the odor measurement unit 30, each substrate 311 may be provided with one structure for detecting odor substances (metal wiring 313 and an odorant receiving layer 315). Alternatively, in the odor measurement unit 30, multiple sets of structures for detecting odor substances (metal wiring 313 and an odorant receiving layer 315) may be provided on a single substrate 311. In the latter case, a constant voltage power supply and a voltmeter are connected to each of the sets provided on the substrate 311 .

[0046] The resin compositions contained in the odorant receiving layers 315 of the multiple odor sensor elements 31 included in the odor measuring unit 30 may be the same or different. If the odorant receiving layers 315 included in the multiple odor sensor elements 31 have the same composition, each of the multiple odorant receiving layers 315 can detect the same odorant. Furthermore, if the multiple odor sensor elements 31 each include odorant receiving layers 315 with different compositions, each of the multiple odorant receiving layers 315 will respond differently to the odorant. In this way, by providing multiple sets of configurations for detecting odorants, the accuracy of odorant identification in the odor measuring unit 30 can be improved.

[0047] (Internal Configuration of Odor Measuring Device 100) Next, the internal configuration of the odor measuring device 100 will be described with reference to Fig. 2. The odor measuring device 100 further includes a control unit 70, an input unit 75, and a storage unit 80. Note that the storage unit 80 may be, for example, a device external to the odor measuring device 100. The input unit 75 is for accepting various input operations from the user, and may be, for example, a keyboard, a mouse, or a touch panel.

[0048] <Controller 70> First, a description will be given of the controller 70. The controller 70 includes a setting unit 71, a flow rate / flow velocity controller 72, a flow path switching unit 73, and an analyzer 74.

[0049] The setting unit 71 performs various settings for the operation of the odor measuring device 100. Specifically, the setting unit 71 sets the operating mode of the odor measuring device 100 based on the measurement conditions input from the input unit 75. The measurement conditions include the temperature inside the temperature adjustment unit 65 during measurement, the flow rate or flow velocity of the second gas, and time information for switching each of the switching valves 12, 14, 22, and 24.

[0050] The flow rate / flow velocity control unit 72 controls at least one of the flow rate and flow velocity of the first gas and the second gas that reach the odor measuring unit 30. Specifically, the flow rate / flow velocity control unit 72 controls the pump 15 to supply the first gas contained in the first supply source 40 to the first flow path 10. In addition, the flow rate / flow velocity control unit 72 controls the flow rate control unit 60 based on the measurement conditions set by the setting unit 71 to control at least one of the flow rate and flow velocity of the second gas.

[0051] The flow path switching unit 73 controls each of the first switching valve 12 , the second switching valve 14 , the third switching valve 22 , and the fourth switching valve 24 .

[0052] The analysis unit 74 acquires the measurement signal output from the odor measurement unit 30 and analyzes the acquired measurement signal. The analysis unit 74 outputs the analysis result of the measurement signal as the measurement result of the odor contained in the first gas. Specifically, the analysis unit 74 outputs the detection result and identification result of the odor substance contained in the first gas. The analysis unit 74 may output the analysis result using a trained model 81 generated by machine learning. Using the trained model 81 enables highly accurate measurement of odor substances.

[0053] <Storage Unit 80> Next, the storage unit 80 will be described. The storage unit 80 may store a trained model 81. Furthermore, measurement signal data and analysis result data may also be stored as necessary. Furthermore, the storage unit 80 may store measurement condition data for the odor measurement device 100.

[0054] The measurement signal data is data of the measurement signal output from the odor measuring unit 30 and acquired by the analysis unit 74. The measurement signal data may be labeled with information about the time of measurement. The analysis result data is data of the analysis result output by the analysis unit 74. The analysis result data may be labeled with information such as the measurement conditions when measuring the odor and the type of measurement signal pattern.

[0055] The trained model 81 is generated by machine learning using training data including a combination of measurement values ​​measured by the odor measurement unit 30 when each of a plurality of odor substances is adsorbed onto at least one sensor element 31 and identification information specific to the odor substance that provided the measurement value. Here, the identification information specific to the odor substance may be, for example, the name, CAS number, or chemical formula of the odor substance. The trained model 81 may also be generated by machine learning using training data including a combination of measurement values ​​measured by the odor measurement unit 30, identification information specific to the odor substance, and evaluation information corresponding to the identification information specific to the odor substance. Here, the evaluation information may be, for example, information indicating the quality of an object that emits an odor substance contained in the measured sample (e.g., a pass or fail product), or the results of a sensory evaluation of the odor. The trained model 81 may also be generated by machine learning using training data including a combination of measurement values ​​measured by the odor measurement unit 30 when a specific odor substance is adsorbed onto the sensor element 31 and evaluation information indicating an evaluation of the odor of an object that emits a specific odor substance contained in the measured sample.

[0056] The trained model 81 may be generated using a known machine learning algorithm. Examples of machine learning algorithms that can be used to generate the trained model 81 include the k-nearest neighbor method, logistic regression, support vector machines, random forests, and neural networks.

[0057] (Processing Performed by Control Unit 70) An outline of a control method for the odor measurement device 100 according to one embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is a flowchart showing an example of a control method performed by the control unit 70 of the odor measurement device 100 according to one embodiment of the present invention.

[0058] In step S1, the setting unit 71 sets the measurement conditions of the measurement device. In step S1, the setting unit 71 may set the measurement conditions to default settings, or may set the measurement conditions to measurement conditions input via the input unit 75.

[0059] In step S2, the flow path switching unit 73 controls each of the third switching valve 22 and the fourth switching valve 24 so that the second gas passes through the second flow path 20. More specifically, in step S2, the flow path switching unit 73 controls the third switching valve 22 so that the second supply unit 21 and the second intermediate unit 23 communicate with each other, and controls the fourth switching valve 24 so that the second intermediate unit 23 and the common unit 50 communicate with each other. This allows the second gas supplied from the second supply source 45 to pass through the second supply unit 21, the second intermediate unit 23, and the common unit 50 in this order, and reach the odor measuring unit 30.

[0060] In step S3, the flow path switching unit 73 controls each of the first switching valve 12 and the second switching valve 14 so that the first gas reaches the first intermediate section 13. More specifically, in step S3, the flow path switching unit 73 controls each of the first switching valve 12 and the second switching valve 14 so that the first gas passes through the first intermediate section 13. In step S3, the flow path switching unit 73 controls the first switching valve 12 so that the first supply section 11 and the first intermediate section 13 communicate with each other, and controls the second switching valve 14 so that the first intermediate section 13 and the gas suction section 16 communicate with each other. This allows the first gas to reach the first intermediate section 13.

[0061] In step S4, the flow rate / flow velocity control unit 72 controls at least one of the flow rate and flow velocity of the second gas so that the second passage time of the second gas passing through the second target section A2 is a predetermined time. More specifically, in step S4, the flow rate / flow velocity control unit 72 controls the flow rate control unit 60 so that the second gas is supplied from the second supply source 45. The flow rate / flow velocity control unit 72 controls the flow rate control unit 60 so that the flow rate or flow velocity of the second gas passing through the second flow path 20 becomes the flow rate or flow velocity set by the measurement conditions set in step S1. When the second gas reaches the odor measurement unit 30, the first gas remaining in the odor measurement unit 30 is removed.

[0062] In step S5, the flow rate and flow velocity control unit 72 supplies the first gas to the first flow path 10. In step S5, the flow rate and flow velocity control unit 72 controls the pump 15 so that the first gas is supplied from the first supply source 40. The flow rate and flow velocity control unit 72 drives the pump 15 to suck the first gas from the first supply source 40, and controls the drive time of the pump 15 to cause the first gas to reach the first intermediate section 13.

[0063] In step S6, the flow path switching unit 73 controls the first switching valve 12 and the second switching valve 14 so that the first gas is retained in the first intermediate section 13. In step S6, the flow path switching unit 73 controls the first switching valve 12 so that the first supply section 11 and the first intermediate section 13 are not in communication with each other, and controls the second switching valve 14 so that the first intermediate section 13 is not in communication with the gas inlet section. More specifically, in step S6, the flow path switching unit 73 controls the first switching valve 12 so that the first intermediate section 13 is in communication with the first connection section 55, and controls the second switching valve 14 so that the first intermediate section 13 is in communication with the second connection section 56. In S6, the flow rate / flow velocity control unit 72 stops driving the pump 15. Note that in step S6, the flow path switching unit 73 may control only the second switching valve 14. That is, the first switching valve 12 may be controlled so that the first supply section 11 and the first intermediate section 13 are in a communication state.

[0064] Although steps S4 to S6 are configured to be performed sequentially, this is not a limitation. Steps S5 and S6 may be performed in parallel with step S4. In this case, while the second gas is removing the first gas from the odor measuring unit 30, the first gas is supplied to the first intermediate section 13 and remains therein.

[0065] In step S7, the flow path switching unit 73 controls each of the first switching valve 12, the second switching valve 14, the third switching valve 22, and the fourth switching valve 24 so that the first gas reaches the odor measuring unit 30. More specifically, in step S7, the flow path switching unit 73 controls the first switching valve 12 so that the second supply unit 21 and the first intermediate unit 13 communicate with each other, controls the second switching valve 14 so that the first intermediate unit 13 and the common unit 50 communicate with each other, controls the third switching valve 22 so that the second supply unit 21 and the first intermediate unit 13 communicate with each other, and controls the fourth switching valve 24 so that the first intermediate unit 13 and the common unit 50 communicate with each other. This allows the second gas to reach the odor measuring unit 30 by passing through the second supply unit 21, the first connecting unit 55, the first intermediate unit 13, the second connecting unit 56, and the common unit 50 in this order. In step S7, the second gas is retained in the second intermediate section 23.

[0066] In step S8, the flow rate / flow velocity control unit 72 controls at least one of the flow rate and flow velocity of the first gas so that the first passing time of the first gas passing through the first target section A1 is a predetermined time. More specifically, in step S8, the flow rate / flow velocity control unit 72 controls the flow rate control unit 60 so that the flow rate or flow velocity of the second gas supplied from the second supply source 45 becomes the flow rate or flow velocity set by the measurement conditions set in step S1. The first gas remaining in the first intermediate section 13 is pressurized by the second gas, passes through the common section 50, and reaches the odor measuring unit 30. This enables the odor measuring unit 30 to measure the odor of the first gas. The flow rate or flow velocity of the first gas passing through the first target section A1 is determined by the flow rate or flow velocity of the second gas supplied from the second supply source 45.

[0067] The flow rate or flow velocity of the second gas in step S8 is substantially the same as the flow rate or flow velocity of the second gas in step S4. In this embodiment, the flow path configuration of the first target section A1 and the flow path configuration of the second target section A2 are substantially the same, so the difference between the first transit time for the first gas to pass through the first target section A1 and the second transit time for the second gas to pass through the second target section A2 can be made small. This makes it possible to keep the difference between the first transit time and the second transit time below a predetermined value.

[0068] In step S9, the analysis unit 74 executes a process of acquiring the measurement signal output from the odor measurement unit 30. The analysis unit 74 may acquire the measurement signal in real time, or may acquire the measurement signal at predetermined time intervals (e.g., 0.1 second intervals). The analysis unit 74 may store the acquired measurement signal in the storage unit 80.

[0069] In step S10, the analysis unit 74 analyzes the odor of the first gas based on the measurement signal output from the odor measurement unit 30. The analysis unit 74 extracts features from the measurement signal of the odor measurement unit 30 and identifies the odor components contained in the first gas. In step S10, the features extracted by the analysis unit 74 may be input into the trained model 81 to perform the current measurement of the odor components contained in the first gas.

[0070] In step S11, the analysis unit 74 outputs the analysis result. The output form of the analysis unit 74 is not particularly limited, and may be, for example, a display output, a print output, or an audio output. The analysis unit 74 may store the analysis result in the storage unit 80.

[0071] If the flow rate control unit 60 is a needle valve, the user operates the needle valve in accordance with steps S4 and S8. In this case, the user operates the needle valve so that the flow rate or flow velocity of the second gas becomes the flow rate or flow velocity set by the measurement conditions set in step S1. In this case, the control unit 70 executes the next step S5 or S9 after the user inputs information indicating that the needle valve operation has been completed in steps S4 and S8. Furthermore, the control unit 70 may, for example, display an operation amount of the needle valve on the display in steps S4 and S8.

[0072] According to the odor measuring device 100, by making the flow path length of the first target section A1 of the first flow path 10 and the flow path length of the second target section A2 of the second flow path 20 substantially the same, the difference between the first transit time of the first gas passing through the first target section A1 and the second transit time of the second gas passing through the second target section A2 is kept below a predetermined value. Therefore, the temperatures of the first gas passing through the first intermediate section 13 and the second gas passing through the second intermediate section 23 are adjusted to temperatures close to the ambient air temperature, thereby reducing the temperature difference between the temperatures of the first gas and the second gas reaching the odor measuring unit 30. This results in stable odor component detection results. Furthermore, by reducing the temperature difference between the temperatures of the first gas and the second gas reaching the odor measuring unit 30, the peak waveform (rising and falling edges of the waveform) of the measurement signal output by the odor measuring unit becomes clear. Therefore, for example, it is possible to distinguish between odor components of similar odors, thereby improving the accuracy of identifying odor components contained in the first gas.

[0073] (Modification) In the first embodiment described above, the flow path configuration of the first intermediate section 13 and the flow path configuration of the second intermediate section 23 are substantially the same, but this is not limited to such a configuration. The flow path configuration of the first intermediate section 13 and the flow path configuration of the second intermediate section 23 may be different. That is, the flow path configuration of the first target section A1 and the flow path configuration of the second target section A2 may be different. In this modification, the flow rate / flow velocity control unit 72 is configured to make the flow rate or flow velocity of the first gas passing through the first target section A1 different from the flow rate or flow velocity of the second gas passing through the second target section A2 of the second flow path 20, so that the difference between the first passing time and the second passing time is equal to or less than a predetermined value.

[0074] For example, if the flow path volume of the second target section A2 and the flow path volume of the first target section A1 are substantially the same, the flow path cross-sectional area of ​​the second target section A2 is larger than the flow path cross-sectional area of ​​the first target section A1, and the flow path length of the second target section A2 is shorter than the flow path length of the first target section A1, the flow rate / flow velocity control unit 72 may control the flow control unit 60 so that the flow rate of the first gas passing through the first target section A1 is faster than the flow rate of the second gas passing through the second target section A2. Thus, in this modification, the flow rate / flow velocity control unit 72 has the function of regulating the temperature of the first gas passing through the first target section A1 and the temperature of the second gas passing through the second target section A2 to predetermined temperatures.

[0075] [Embodiment 2] Another embodiment of the present invention will be described below with reference to Figures 5 and 6. For ease of explanation, components having the same functions as those described in the above embodiments will be denoted by the same reference numerals, and their description will not be repeated. The odor measurement device 100A in embodiment 2 differs from the odor measurement device 100 in embodiment 1 in that it does not include multiple solenoid valves.

[0076] 5 and 6, the odor measuring device 100A includes one eight-way solenoid valve 90 controlled by the flow path switching unit 73. The eight-way solenoid valve 90 is a solenoid valve having eight connection ports P1 to P8. The eight-way solenoid valve 90 includes a first selector valve 91, a second selector valve 92, a third selector valve 93, and a fourth selector valve 94.

[0077] The first switching valve 91 has connection ports P1 and P2, which are connected to each other by an internal flow path 911. The second switching valve 92 has connection ports P3 and P4, which are connected to each other by an internal flow path 921. The third switching valve 93 has connection ports P5 and P6, which are connected to each other by an internal flow path 931. The fourth switching valve 94 has connection ports P7 and P8, which are connected to each other by an internal flow path 941.

[0078] 5 shows a state in which the second gas can reach the odor measuring unit 30. More specifically, the first supply unit 11 is connected to the connection port P1, and the first intermediate unit 13 is connected to the connection port P2. The gas suction unit 16 is connected to the connection port P3, and the first intermediate unit 13 is connected to the connection port P4. Furthermore, the connection port P5 is connected to the second supply unit 21, and the connection port P6 is connected to the second intermediate unit 23. The connection port P7 is connected to the second intermediate unit 23, and the connection port P8 is connected to the common unit 50. As a result, the second gas passes through the second supply unit 21, the second intermediate unit 23, and the common unit 50 in this order before reaching the odor measuring unit 30. Furthermore, the first gas can be retained in the first intermediate unit 13.

[0079] 6 shows a state in which the first gas can reach the odor measuring unit 30. More specifically, the connection port P1 is connected to the first intermediate section 13, the connection port P2 is connected to the second supply section 21, the connection port P3 is connected to the first supply section 11, the connection port P4 is connected to the gas suction section 16, the connection port P5 is connected to the second intermediate section 23, the connection port P6 is connected to the second intermediate section 23, the connection port P7 is connected to the common section 50, and the connection port P8 is connected to the first intermediate section 13. As a result, the first gas retained in the first intermediate section 13 is pressurized by the second gas and reaches the odor measuring unit 30. Furthermore, the second gas can be retained in the second intermediate section 23.

[0080] The solenoid valve generates heat when energized. Therefore, if the odor measuring device includes multiple solenoid valves, the degree of heat generation of each solenoid valve may differ. As a result, the first gas passing through the first flow path 10 and the second gas passing through the second flow path 20 are likely to be affected to different degrees by the heat generated by the solenoid valves. In a configuration using the eight-way solenoid valve 90, the first selector valve 91, the second selector valve 92, the third selector valve 93, and the fourth selector valve 94 are configured as a single solenoid valve. Therefore, both the first gas and the second gas are affected by the heat generated by the eight-way solenoid valve 90 when energized. This reduces the temperature difference between the first gas and the second gas reaching the odor measuring unit 30. In other words, the eight-way solenoid valve 90 has the function of regulating the temperature of the first gas passing through the first target section A1 and the temperature of the second gas passing through the second target section A2 to predetermined temperatures.

[0081] [Example of Software Implementation] In the odor measurement devices 100 and 100A, the control block (particularly the control unit 70) may be implemented by a logic circuit (hardware) formed on an integrated circuit (IC chip) or the like, or may be implemented by software.

[0082] In the latter case, the odor measuring device 100, 100A includes a computer that executes instructions from a software program that realizes each function. This computer includes, for example, one or more processors and a computer-readable recording medium storing the program. The object of the present invention is achieved by the computer having the processor read and execute the program from the recording medium. The processor may be, for example, a central processing unit (CPU). The recording medium may be a "non-transitory tangible medium," such as a read-only memory (ROM), tape, disk, card, semiconductor memory, or programmable logic circuit. The device may also include a random access memory (RAM) for expanding the program. The program may be supplied to the computer via any transmission medium capable of transmitting the program (such as a communication network or broadcast waves). One aspect of the present invention may also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

[0083] [Summary] A measurement device according to a first aspect of the present invention includes an odor measuring unit that measures the odor of a first gas that has arrived from a first supply source; a first flow path through which the first gas passes before reaching the odor measuring unit, the first flow path including, in order from the first supply source toward the odor measuring unit, a first supply unit connected to the first supply source, a first switching valve, a first intermediate unit, and a second switching valve; and a flow path through which a second gas, which is a gas different from the first gas and arrives at the odor measuring unit from a second supply source different from the first supply source and is used to remove the first gas from the odor measuring unit, passes before reaching the odor measuring unit, the first flow path including, in order from the first supply source toward the odor measuring unit, a first switching valve, a first intermediate unit, and a second switching valve. The device is provided with a second flow path having, in order from the second supply source toward the odor measuring unit, a second supply unit connected to the second supply source, a third switching valve, a second intermediate unit, and a fourth switching valve, wherein a first target section which is at least a portion of the section between the first switching valve and the odor measuring unit of the first flow path, and a second target section which is at least a portion of the section between the third switching valve and the odor measuring unit of the second flow path are temperature-controlled, and are configured so that the difference between the first transit time for the first gas to pass through the first target section and the second transit time for the second gas to pass through the second target section is equal to or less than a predetermined value.

[0084] In a measuring device according to aspect 2 of the present invention, in the above-described aspect 1, the first flow path may have a common section connected to the odor measuring section, the second flow path may have the common section, and the first target section and the second target section may at least include the common section.

[0085] In a measuring device according to aspect 3 of the present invention, in the above aspect 1, the first flow path includes a common section connected to the odor measuring section, the second flow path includes the common section, the first switching valve is a valve capable of switching between connecting the first supply section to the first intermediate section or connecting the second supply section to the first intermediate section, the second switching valve is a valve capable of switching between connecting the first intermediate section to the common section, the third switching valve is a valve capable of switching between connecting the second supply section to the second intermediate section, and the fourth switching valve is a valve capable of switching between connecting the second intermediate section to the common section, and the first target section and the second target section may include at least the common section.

[0086] In the measuring device according to aspect 4 of the present invention, in the above-mentioned aspect 3, the first switching valve, the second switching valve, the third switching valve, and the fourth switching valve may be constituted by one or more solenoid valves having two or more connection ports.

[0087] A fifth aspect of the present invention relates to the measuring device of the fourth aspect, wherein each of the first selector valve, the second selector valve, the third selector valve, and the fourth selector valve may be a three-way electromagnetic valve.

[0088] A measuring device according to a sixth aspect of the present invention is the measuring device according to the fourth aspect described above, wherein the first switching valve, the second switching valve, the third switching valve, and the fourth switching valve may be configured using eight-way electromagnetic valves.

[0089] In a measurement device according to a seventh aspect of the present invention, in correspondence with any one of the first to sixth aspects, a heat insulating material may be provided in the first target section and the second target section.

[0090] In the measuring device of aspect 8 of the present invention, in the above aspect 1, a flow rate / flow velocity control unit may be provided that controls the flow rate and flow velocity of the first gas and the second gas that reach the odor measuring unit.

[0091] In the measuring device of aspect 9 of the present invention, in any of aspects 1 to 6 above, the flow paths of the first target section and the second target section may be made of the same material and have substantially the same flow path cross-sectional area.

[0092] In the measuring device according to Aspect 10 of the present invention, in Aspect 9 above, the flow paths of the first target section and the second target section may have the same thermal conductivity.

[0093] In the measurement device according to Aspect 11 of the present invention, in any one of Aspects 1 to 10 above, the odor measurement unit may be temperature-controlled.

[0094] The present invention 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 invention.

[0095] REFERENCE SIGNS LIST 10 First flow path 11 First supply section 12 First switching valve 13 First intermediate section 14 Second switching valve 20 Second flow path 21 Second supply section 22 Third switching valve 23 Second intermediate section 24 Fourth switching valve 30 Odor measuring section 40 First supply source 45 Second supply source 50 Common section 60 Flow rate control unit 70 Control section 72 Flow rate / flow velocity control section 100 Odor measuring device

Claims

1. An odor measuring unit that measures the odor of a first gas that has arrived from a first supply source; a first flow path through which the first gas passes before reaching the odor measuring unit, the first flow path comprising, in order from the first supply source toward the odor measuring unit, a first supply part connected to the first supply source, a first switching valve, a first intermediate part, and a second switching valve; and a second flow path through which a second gas, which is a gas different from the first gas and arrives at the odor measuring unit from a second supply source different from the first supply source and is used to remove the first gas from the odor measuring unit, passes before reaching the odor measuring unit, the second flow path comprising, in order from the second supply source toward the odor measuring unit, a second supply part connected to the second supply source, a third switching valve, a second intermediate part, and a fourth switching valve; wherein a first target section that is at least a portion of the first flow path between the first switching valve and the odor measuring unit, and a second target section that is at least a portion of the second flow path between the third switching valve and the odor measuring unit are temperature-controlled; an odor measuring device configured so that a difference between a first transit time for the first gas to pass through the first target section and a second transit time for the second gas to pass through the second target section is equal to or less than a predetermined value.

2. The odor measuring device described in claim 1, wherein the first flow path has a common portion connected to the odor measuring unit, the second flow path has the common portion, and the first target section and the second target section include at least the common portion.

3. The odor measuring device described in claim 1, wherein the first flow path has a common section connected to the odor measuring section, the second flow path has the common section, the first switching valve is a valve that can switch between connecting the first supply section to the first intermediate section or connecting the second supply section to the first intermediate section, the second switching valve is a valve that can switch between connecting the first intermediate section to the common section or not, the third switching valve is a valve that can switch between connecting the second supply section to the second intermediate section or not, and the fourth switching valve is a valve that can switch between connecting the second intermediate section to the common section or not, and the first target section and the second target section at least include the common section.

4. The odor measuring device described in claim 3, wherein the first switching valve, the second switching valve, the third switching valve, and the fourth switching valve are constituted by one or more solenoid valves having two or more connection ports.

5. The odor measuring device according to claim 4, wherein each of the first selector valve, the second selector valve, the third selector valve, and the fourth selector valve is a three-way electromagnetic valve.

6. The odor measuring device according to claim 4, wherein the first switching valve, the second switching valve, the third switching valve, and the fourth switching valve are configured using eight-way electromagnetic valves.

7. The odor measuring device according to any one of claims 1 to 6, wherein the first target section and the second target section are provided with a heat insulating material.

8. The odor measuring device according to claim 1, further comprising a flow rate / flow velocity control unit that controls the flow rate and flow velocity of the first gas and the second gas that reach the odor measuring unit.

9. An odor measuring device according to any one of claims 1 to 6, wherein the flow paths of the first target section and the second target section are made of the same material and have substantially the same flow path cross-sectional area.

10. The odor measuring device according to claim 9, wherein the flow paths of the first target section and the second target section have the same thermal conductivity.

11. An odor measuring device according to any one of claims 1 to 10, wherein the odor measuring unit is also temperature-controlled along with the first target section and the second target section.

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