Odor measurement device

Abstract

The purpose of the present invention is to reduce the disparity in the detection sensitivities of a plurality of odor sensor elements arranged in an internal space. An odor measurement device according to the present invention comprises: an odor sensor unit (330) comprising a plurality of odor sensor elements (31) that detect the odor of a target gas supplied to an internal space (325); and a first relay path (340) having a first end connected to a first wall section (321) at a first opening (341) provided in the first wall section (321), and having a second end that is on the opposite side from the first end and is connected to a common part (50) connected to a supply source for the target gas. The first relay path (340) has at least one curved section (343).

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 multiple odor sensor elements for detecting odor components, and detect the odor components contained in the target gas based on measurement signals output from the multiple odor sensor elements.

[0003] For example, Patent Document 1 describes a vapor sensing device for sensing the presence and concentration of a specified vapor. In the vapor sensing device, a sensor module including multiple chemical sensing sensors is attached to a sample chamber. The sample is introduced from an intake port through the sample chamber to an exhaust port. The multiple chemical sensing sensors are arranged side by side in the flow direction of the sample flowing from the intake port to the exhaust port.

[0004] Japan Special Table No. 2003-526768

[0005] In the vapor sensing device of Patent Document 1, the sample is sent to the sample chamber via an intake port. However, if the linear velocity of the sample passing through the intake port varies, the linear velocity of the sample passing through the sample chamber also varies. Therefore, when multiple chemical sensing sensors are arranged in a line in the sample flow direction, as in Patent Document 1, it is conceivable that the detection accuracy of chemical substances contained in the sample will vary between the chemical sensing sensors located on the intake port side and the chemical sensing sensors located on the discharge port side.

[0006] An object of one aspect of the present invention is to reduce variations in detection accuracy among a plurality of odor sensor elements arranged in an internal space.

[0007] In order to solve the above problem, an odor measuring device according to one embodiment of the present invention comprises an odor sensor unit having a plurality of odor sensor elements that detect the odor of a target gas supplied to an internal space defined by one or more wall portions, and a first relay path having a first end connected to the wall portion at a first opening provided in the wall portion and a second end opposite the first end connected to a first flow path that is connected to a supply source of the target gas, the first relay path having at least one bend.

[0008] According to one aspect of the present invention, it is possible to reduce variations in the detection accuracy of a plurality of odor sensor elements arranged in an internal space.

[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 schematic diagram showing an example of the configuration of an odor measurement unit. FIG. 5 is a schematic diagram showing an example of the configuration of an odor measurement unit. FIG. 6 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. 7 is a schematic diagram showing an example of the configuration of an odor measurement unit. FIG. 8 is a schematic diagram showing the configuration of an odor measurement unit according to Example 1 and Example 2. FIG. 9 is a schematic diagram showing the configuration of an odor measurement unit according to Comparative Example 1. FIG. 10 is a graph showing the measurement results of the waveform intensity of a measurement signal output from an odor sensor element.

[0010] [Embodiment 1] (Outline of Odor Measuring Device 100) First, an outline of an odor measuring 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 measuring device 100 according to one embodiment of the present invention. The odor measuring device 100 is a device that detects odor components contained in a gas to be measured. As shown in Fig. 1, the odor measuring device 100 includes a first supply path 10, a second supply path 20, an odor measuring unit 30, an exhaust unit 51, a flow rate control unit 60, and a temperature adjustment unit 65.

[0011] The first supply path 10 is a flow path connectable to a first supply source 40 that contains a first gas to be measured. In this specification, the first gas is a target gas whose odor is to be measured by the odor sensor unit 330, which will be described later. The first supply source 40 is, for example, a sampling bag, a vial, a medium bottle, or a syringe. The first supply path 10 is a flow path through which the first gas passes from the first supply source 40 to the odor measuring unit 30. That is, the first gas supplied from the first supply source 40 passes through the first supply path 10 and reaches the odor measuring unit 30. The first supply 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.

[0012] 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.

[0013] The first supply 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 supply path 10. The gas suction unit 16 is connected to the pump 15, and is connected to the first intermediate section 13 via the second switching valve 14. The gas suction unit 16 is, for example, a pipe.

[0014] 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.

[0015] 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.

[0016] The second supply path 20 is a flow path connectable to a second supply source 45 that accommodates 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 supply 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 supply path 20 and reaches the odor measurement unit 30. The second supply 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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 supply path 10 and the second supply 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. The common part 50 is an example of a first flow path.

[0021] 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 supply path 10 and the second supply path 20 are each connected to the odor measuring section 30 from 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.

[0022] The exhaust unit 51 is a flow path for exhausting the first gas and the second gas that have passed through the odor measuring unit 30 to the outside of the odor measuring unit 30. The exhaust unit 51 is, for example, a pipe. The exhaust unit 51 is an example of a second flow path. Note that the odor measuring device 100 does not necessarily have to include the exhaust unit 51.

[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 supply path 10 and the second target section A2 of the second supply 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 measurement device 100, the first target section A1 of the first supply path 10 and the second target section A2 of the second supply path 20 are temperature-controlled. The first target section A1 is a section of the first supply path 10 between the first switching valve 12 and the odor measurement unit 30. The second target section A2 is a section of the second supply path 20 between the third switching valve 22 and the odor measurement unit 30. That is, the odor measurement device 100 controls 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 measurement 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 measurement 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 measurement unit 30. Note that it is preferable that the odor measurement unit 30 is also temperature-controlled.

[0026] In this embodiment, the first target section A1 of the first supply path 10 is the first intermediate section 13 and the common section 50, and the second target section A2 of the second supply 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] 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.

[0028] 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 supply path 10 and the flow paths arranged in the second target section A2 of the second supply path 20.

[0029] 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.

[0030] 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).

[0031] In this way, symmetry is provided between the flow path configuration of the first target section A1 of the first supply path 10 and the flow path configuration of the second target section A2 of the second supply 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 adjust 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 adjusting the temperatures of the gases passing through them.

[0032] 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 supply path 20 to warm the temperature of the second gas from below room temperature to approximately room temperature.

[0033] (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).

[0034] 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.

[0035] 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.

[0036] 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.

[0037] <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.

[0038] 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.

[0039] 3, metal wiring 313 including first metal wiring 313A and second metal wiring 313B may be disposed on a substrate 311. The substrate 311 may be a substrate such as glass epoxy commonly used in electronic circuits. The metal wiring 313 may be metal wiring such as copper or gold.

[0040] 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.

[0041] 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.

[0042] 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 .

[0043] 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.

[0044] (Configuration of odor measuring unit 30) Next, the configuration of the odor measuring unit 30 will be described with reference to Figures 4 and 5. Figures 4 and 5 are schematic diagrams showing an example of the configuration of the odor measuring unit 30. As shown in Figures 4 and 5, the odor measuring unit 30 further includes a housing 320, an odor sensor unit 330, a first relay path 340, and a second relay path 350.

[0045] The housing 320 is a container having an internal space 325 through which odorant-containing gas can pass. The internal space 325 is a space defined by one or more walls. In one example, the internal space 325 of this embodiment is a rectangular parallelepiped and defined by six walls. In FIGS. 4 and 5 , the internal space 325 is a space defined by a first wall 321, a second wall 322, a third wall 323, and a fourth wall 324. The internal space 325 is not limited to a space whose cross section perpendicular to the flow direction X of the internal space 325 is rectangular. The internal space 325 may have any cross section perpendicular to the flow direction X, such as a polygonal, circular, semicircular, or crescent shape. For example, the internal space 325 may have a polygonal prism shape, a cylindrical shape, or a circular shape. When the internal space 325 is circular, the internal space 325 is defined by a single wall. Furthermore, in the case of the internal space 325 having a rectangular parallelepiped shape or a polygonal prism shape, the corners of the internal space 325 may be configured with curved surfaces.

[0046] In the internal space 325, the first gas that flows in through the first opening 341 flows toward the second opening 351 and is discharged to the outside through the second opening 351. That is, as shown in Figures 4 and 5, the flow direction of the first gas in the internal space 325 is the direction indicated by arrow X. Hereinafter, the flow direction of the first gas in the internal space 325 will be referred to as "flow direction X." Note that the flow direction of the second gas in the internal space 325 is the same as the flow direction of the first gas.

[0047] A plurality of odor sensor elements 31 are installed within the internal space 325. In this embodiment, eight odor sensor elements 31 are installed in the first wall portion 321. The plurality of odor sensor elements 31 and the internal space 325 constitute an odor sensor unit 330 that detects the odor of the first gas supplied to the internal space 325. Note that it is sufficient that a plurality of odor sensor elements 31 are installed in the first wall portion 321. For example, two to seven odor sensor elements 31 may be installed in the first wall portion 321, or nine or more odor sensor elements 31 may be arranged. The number of odor sensor elements 31 installed in the first wall portion 321 may be, for example, 16 or 32.

[0048] The multiple odor sensor elements 31 installed on the first wall portion 321 are arranged along the flow direction X. With this configuration, the cross-sectional area of ​​the internal space 325 perpendicular to the flow direction X (hereinafter referred to as the cross-sectional area of ​​the internal space 325) is reduced. This reduces the amount of first gas supplied to the odor sensor unit 330. The multiple odor sensor elements 31 are preferably arranged in series in the flow direction X. This configuration allows each of the serially arranged odor sensor elements 31 to be uniformly exposed to the first gas or the second gas passing through the internal space 325. The multiple odor sensor elements 31 may be arranged in a zigzag pattern in the flow direction X. Furthermore, an odor sensor element 31 arranged in parallel in a direction intersecting the flow direction X may be installed on the first wall portion 321 with at least one of the multiple odor sensor elements 31 arranged along the flow direction X.

[0049] The first relay path 340 is provided inside the housing 320. The first relay path 340 is a flow path that relays between the common part 50 and the internal space 325. The first relay path 340 includes a first end and a second end. It is preferable that the first relay path 340 is a flow path having a substantially uniform flow path cross-sectional area from the first end to the second end. The first relay path 340 is a flow path having a circular flow path cross-section in a direction perpendicular to the gas flow direction. The flow path cross-section of the first relay path 340 is not limited to a circular shape and may be rectangular.

[0050] A first end of the first relay path 340 is connected to the first wall portion 321 at a first opening 341 provided in the first wall portion 321. That is, the first end of the first relay path 340 is the first opening 341, and the first relay path 340 is connected to the internal space 325 via the first opening 341. The first opening 341 is an opening facing in a direction intersecting the flow direction X. The first opening 341 is formed upstream of the odor sensor element 31A, which is located most upstream among the multiple odor sensor elements 31, in the flow direction X.

[0051] The second end of the first relay path 340 is located on the opposite side to the first end of the first relay path 340. The second end of the first relay path 340 is a third opening 342 formed in the outer wall surface of the housing 320, and is connected to the common part 50. More specifically, the second end of the first relay path 340 is connected to the common part 50 via a connecting member 53 provided in the third opening 342. The third opening 342 is an opening facing in the direction opposite to the flow direction X.

[0052] The first relay path 340 has one bent portion 343. The angle of the bent portion 343 is 90°. The first relay path 340 has an L-shape. The angle of the bent portion 343 is, for example, 10° to 90°. Note that the angle of the bent portion 343 may be greater than 90°. Furthermore, the first relay path 340 may have multiple bent portions 343.

[0053] The second relay path 350 is provided inside the housing 320. The second relay path 350 is a flow path that relays between the internal space 325 and the discharge section 51. The second relay path 350 includes a third end and a fourth end. It is preferable that the second relay path 350 is a flow path having a substantially uniform flow path cross-sectional area from the third end to the fourth end. The second relay path 350 is a flow path having a circular flow path cross-section in a direction perpendicular to the gas flow direction. The flow path cross-section of the second relay path 350 is not limited to a circular shape and may be rectangular.

[0054] A third end of the second relay path 350 is connected to the second wall portion 322 at a second opening 351 provided in the second wall portion 322. That is, the third end of the second relay path 350 is the second opening 351, and the second relay path 350 is connected to the internal space 325 via the second opening 351. The second wall portion 322 is a wall portion facing the first wall portion 321. The second opening 351 is an opening facing in a direction intersecting the flow direction X. The second opening 351 is formed downstream of the odor sensor element 31B, which is located furthest downstream among the multiple odor sensor elements 31, in the flow direction X.

[0055] A fourth end of the second relay path 350 is located on the opposite side to the third end of the second relay path 350. The fourth end of the second relay path 350 is a fourth opening 352 formed in the outer wall surface of the housing 320, and is connected to the discharge unit 51. More specifically, the fourth end of the second relay path 350 is connected to the discharge unit 51 via a connecting member 53 provided in the fourth opening 352. The fourth opening 352 is an opening facing in approximately the same direction as the flow direction X.

[0056] In this way, by having the third opening 342 facing in the opposite direction to the flow direction X and the fourth opening 352 facing in approximately the same direction as the flow direction X, the size of the odor measuring unit 30 in the direction of arrow L2 is smaller than when the third opening 342 and the fourth opening 352 face in a direction perpendicular to the flow direction X. This allows for space savings.

[0057] The second relay path 350 has one bent portion 353. The angle of the bent portion 353 is 90°. The second relay path 350 has an L-shape. The angle of the bent portion 353 is, for example, 10° to 90°. Note that the angle of the bent portion 353 may be greater than 90°. Furthermore, the second relay path 350 may have multiple bent portions 353.

[0058] The cross-sectional area of ​​the internal space 325 is equal to or smaller than the flow path cross-sectional area of ​​the common part 50. This makes it possible to reduce the amount of the first gas supplied to the internal space 325. Furthermore, the flow path cross-sectional area of ​​the first relay path 340 is larger than the flow path cross-sectional area of ​​the common part 50. This makes it possible to reduce the risk of the odor sensor element 31 being damaged by the pressure of the gas supplied from the common part 50.

[0059] The cross-sectional area of ​​the flow path of the common part 50 is 0.5 mm ２ ~32mm ２ It is preferable that the common part 50 is a pipe having an inner diameter of 1 / 4 inch or less. For example, the common part 50 is a pipe having an inner diameter of 1 / 16 inch, and the flow path cross-sectional area of ​​the common part 50 is 1.98 mm ２ The common part 50 may be a pipe with an inner diameter of ¼ inch, ⅛ inch, or 1 / 32 inch. With this configuration, the difference between the cross-sectional area of ​​the internal space 325 and the cross-sectional area of ​​the flow path of the common part 50 is reduced. This reduces the risk of the odor measuring unit 30 being damaged by pressure.

[0060] In this embodiment, the cross-sectional area of ​​the first relay path 340 is smaller than the cross-sectional area of ​​the internal space 325. For example, the inner diameter of the first relay path 340 is 2 mm, and the cross-sectional area of ​​the first relay path 340 is approximately 3 mm. ２ For example, the width of the internal space 325 is 3.5 mm, the thickness of the internal space 325 is 0.5 mm, and the cross-sectional area of ​​the internal space 325 is 1.75 mm. ２Depending on the configuration of the odor sensor element 31 installed on the wall of the internal space 325, the flow path cross-sectional area of ​​the first relay path 340 may be larger than the cross-sectional area of ​​the internal space 325. For example, if the number of odor sensor elements 31 installed on the wall of the internal space 325 is small, the flow path cross-sectional area of ​​the first relay path 340 may be larger than the cross-sectional area of ​​the internal space 325. Furthermore, depending on the size of the odor sensor element 31, the cross-sectional area of ​​the internal space 325 may be smaller than the flow path cross-sectional area of ​​the first relay path 340.

[0061] The volume of the internal space 325 is determined according to the number of odor sensor elements 31 installed in the internal space 325. When eight odor sensor elements 31 are installed in the first wall portion 321, the internal space 325 is, for example, 43.5 mm long, 3.5 mm wide, and 0.5 mm high. Here, the length of the internal space 325 is the length in the direction indicated by arrow L1 in FIGS. 4 and 5 , which is the length in the left-right direction on the paper. The width of the internal space 325 is the length in the depth direction on the paper in FIGS. 4 and 5 . The height of the internal space 325 is the length in the direction indicated by arrow L2 in FIGS. 4 and 5 , which is the length in the up-down direction on the paper.

[0062] Furthermore, for example, when eight odor sensor elements 31 are installed, the volume of the internal space 325 is, for example, 0.076 ml. For example, when eight odor sensor elements 31 are installed, the volume of the internal space 325 may be 0.07 to 0.46 ml, preferably 0.07 to 0.09 ml. The volume of the internal space 325 is 0.009 ml or less per odor sensor element 31 provided on the wall of the internal space 325. The volume of the internal space 325 may be 0.009 ml to 0.035 ml, preferably 0.009 ml to 0.011 ml per odor sensor element 31 provided on the wall of the internal space 325. This configuration prevents the cross-sectional area of ​​the internal space 325 from becoming unnecessarily large. This allows the amount of first gas supplied to the odor sensor unit 330 to be reduced.

[0063] The length from the first end to the second end of the first relay path 340 may be, for example, 6 mm to 8 mm. The inner diameter of the second relay path 350 is, for example, 2 mm. The length from the third end to the fourth end of the second relay path 350 may be, for example, 6 mm to 8 mm. In this embodiment, the first relay path 340 and the second relay path 350 are structurally symmetrical. Note that the structure of the first relay path 340 and the structure of the second relay path 350 may be different.

[0064] Alternatively, the housing 320 may be a container made up of multiple members. For example, the housing 320 may be made up of a first member 326 having a first wall portion 321, a second member 327 having a second wall portion 322, and a spacer 328 disposed between the first member 326 and the second member 327. In this case, a through hole is formed in the spacer 328, and the through hole forms an internal space 325 of the housing 320. That is, the spacer 328 has a third wall portion 323 and a fourth wall portion 324, and the height (thickness) of the spacer 328 in the direction indicated by arrow L2 is the same as the height of the internal space 325. In this case, a first relay path 340 is formed in the first member 326, and a second relay path 350 is formed in the second member 327. By forming the first relay path 340 and the second relay path 350 in a member separate from the spacer 328, the configuration of the spacer 328 does not depend on the first relay path 340 and the second relay path 350. This simplifies the configuration of the housing 320. Furthermore, by changing the height of the spacer 328, the volume of the internal space 325 can be freely changed.

[0065] (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.

[0066] <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.

[0067] 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.

[0068] 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 supply 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.

[0069] 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 .

[0070] 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.

[0071] <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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] (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. 6. Fig. 6 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.

[0076] 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.

[0077] 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 supply 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.

[0078] 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.

[0079] 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 supply 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.

[0080] In step S5, the flow rate and flow velocity control unit 72 supplies the first gas to the first supply 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] According to the configuration of the odor measuring device 100, the bent portion 343 of the first relay path 340 of the odor measuring unit 30 allows the first gas, whose linear velocity is adjusted, to flow into the internal space 325. Therefore, the first gas can pass through the internal space 325 at a uniform linear velocity. This reduces variation in the detection accuracy of the multiple odor sensor elements 31 arranged in the internal space 325. That is, variation in odor detection accuracy between the odor sensor element 31A located most upstream and the odor sensor element 31B located most downstream in the flow direction X is reduced.

[0091] Furthermore, by providing the odor measuring unit 30 with the second relay path 350, the linear velocity of the first gas is made uniform at the bent portion 353 of the second relay path 350, and the first gas in the internal space 325 is uniformly discharged from the second relay path 350. This prevents a decrease in the accuracy of odor detection by the odor sensor element 31 located downstream in the flow direction X.

[0092] Because the first opening 341 and the second opening 351 are both oriented in a direction intersecting the flow direction X, the linear velocity of the first gas flowing into the internal space 325 is uniformized, and the linear velocity of the first gas exhausted from the internal space 325 is also uniformized. This reduces the variation in the linear velocity of the first gas within the internal space 325. This further reduces the variation in the detection accuracy of the multiple odor sensor elements arranged in the internal space.

[0093] The configuration including the temperature adjustment unit 65 adjusts the temperature of the first gas supplied to the odor measuring unit 30 and / or the temperature inside the odor measuring unit 30. This stabilizes the accuracy of odor detection by the multiple odor sensor elements 31.

[0094] [Modification] A modification of the present invention will be described below with reference to Fig. 7. For ease of explanation, components having the same functions as those described in the above embodiment will be denoted by the same reference numerals, and their description will not be repeated. The odor measuring unit 30A according to this modification includes 16 odor sensor elements 31.

[0095] 7 , in the odor measuring unit 30A according to this modification, multiple odor sensor elements 31 are installed on the first wall portion 321 and the second wall portion 322. More specifically, eight odor sensor elements 31 are installed on each of the first wall portion 321 and the second wall portion 322. That is, a total of 16 odor sensor elements 31 are installed in the internal space 325. Each of the multiple odor sensor elements 31 installed on the second wall portion 322 may face each of the multiple odor sensor elements 31 installed on the first wall portion 321.

[0096] The first opening 341 is formed upstream of the odor sensor element 31C, which is the most upstream of the multiple odor sensor elements 31 installed on the second wall portion 322, in the flow direction X. The second opening 351 is formed downstream of the odor sensor element 31D, which is the most downstream of the multiple odor sensor elements 31 installed on the second wall portion 322, in the flow direction X.

[0097] When 16 odor sensor elements 31 are installed in the internal space 325, the internal space 325 may have, for example, a length of 43.5 mm, a width of 3.5 mm, and a height of 0.5 mm. The volume of the internal space 325 may be, for example, 0.076 ml. For example, when 16 odor sensor elements 31 are installed, the volume of the internal space 325 may be 0.07 ml to 0.92 ml, and preferably 0.07 ml to 0.18 ml.

[0098] According to the configuration of the odor measuring unit 30A of this modification, the multiple odor sensor elements 31 installed on each of the first wall portion 321 and the second wall portion 322 that define the internal space 325 detect the odor of the first gas supplied into the same internal space 325. This makes it possible to reduce the amount of the first gas supplied to the odor sensor unit 330.

[0099] The plurality of odor sensor elements 31 may be installed on each of the first wall portion 321 and the second wall portion 322 that define the internal space 325. The plurality of odor sensor elements 31 may also be configured to be installed on three or more of the plurality of walls that define the internal space 325.

[0100] In this modified example, eight odor sensor elements 31 are installed on each of the first wall portion 321 and the second wall portion 322, but this configuration is not limited thereto. Two to seven odor sensor elements 31 may be installed on each of the first wall portion 321 and the second wall portion 322, or nine or more odor sensor elements 31 may be arranged. The number of odor sensor elements 31 installed on the first wall portion 321 may differ from the number of odor sensor elements 31 installed on the second wall portion 322. Either the first wall portion 321 or the second wall portion 322 may be configured to have one odor sensor element 31 installed. Furthermore, one odor sensor element 31 may be installed on each of the first wall portion 321 and the second wall portion 322, and the position of the one odor sensor element 31 installed on the first wall portion 321 may be different from the position of the one odor sensor element 31 installed on the second wall portion 322 in the flow direction X.

[0101] [Other Modifications] In the above-described embodiment, the second opening 351 is formed in the second wall portion 322, but the present invention is not limited to this configuration. The second opening 351 may be formed in the first wall portion 321 in which the first opening 341 is formed.

[0102] Furthermore, in the above-described embodiment, the first opening 341 is formed in the first wall portion 321 on which the multiple odor sensor elements 31 are installed, but this is not limited to this configuration. The first opening 341 may be formed in the second wall portion 322 or the third wall portion 323. Furthermore, when the first opening 341 is formed in the third wall portion 323, the second opening 351 may be formed in the fourth wall portion 324. In this case, the first opening 341 and the second opening 351 are openings that face in approximately the same direction as the flow direction X.

[0103] [Other Embodiments] In the above-described embodiment, the first supply path 10 and the second supply path 20 are connected to the odor measuring unit 30, but the present invention is not limited to such a configuration. For example, the odor measuring unit 30 may be configured to be connected only to the common unit 50.

[0104] In the above-described embodiment, the first gas is supplied to the odor measuring unit 30 by pressure-feeding the first gas with the second gas, but the present invention is not limited to this configuration. For example, a pump that sucks in the first gas and the second gas may be provided in the discharge unit 51, and the first gas and the second gas may be supplied to the odor measuring unit 30 by the pump.

[0105] In the above-described embodiment, the first selector valve 12, the second selector valve 14, the third selector valve 22, and the fourth selector valve 24 of the odor measuring device 100 are three-way solenoid valves, but the present invention is not limited to this configuration. The first selector valve 12 and the third selector valve 22 may be configured as solenoid valves having four connection ports, and the second selector valve 14 and the fourth selector valve 24 may be configured as solenoid valves having four connection ports. Furthermore, the first selector valve 12, the second selector valve 14, the third selector valve 22, and the fourth selector valve 24 may be configured as solenoid valves having eight connection ports.

[0106] The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to these.

[0107] Examples 1 and 2 will be described with reference to Fig. 8 . Fig. 8 is a schematic diagram showing the configuration of the odor measurement unit 30 according to Examples 1 and 2. The odor measurement units 30A1 and 30A2 according to Examples 1 and 2 employ the configuration of the odor measurement unit 30A according to the above-described modified example. Note that in Fig. 8 , for ease of explanation, the same reference numerals are used for components having the same functions as those described in the above embodiment.

[0108] Example 1 The reference numeral 800 in Figure 8 indicates an odor measuring unit 30A1 according to Example 1. The first relay path 340 and the second relay path 350 each had an inner diameter of Φ2. That is, the size of the third opening 342 and the fourth opening 352 was also Φ2. The volume of the internal space 325 was 0.61 ml. The height of the internal space 325 was 3 mm. That is, the height of the spacer 328 was 3 mm.

[0109] Example 2 The reference numeral 801 in Figure 8 indicates an odor measuring unit 30A2 according to Example 2. The first relay path 340 and the second relay path 350 each had an inner diameter of Φ2. That is, the size of the third opening 342 and the fourth opening 352 was also Φ2. The volume of the internal space 325 was 0.25 ml. The height of the internal space 325 was 1 mm. That is, the height of the spacer 328 was 1 mm.

[0110] In Examples 1 and 2, the odor sensor elements 31A and 31C located most upstream in the flow direction X and the odor sensor elements 31B and 31D located most downstream in the flow direction X were sensor elements equipped with an odorant receiving layer 315 containing a silicone resin. In Examples 1 and 2, the odor sensor element 31M located between the odor sensor element 31A and the odor sensor element 31B in the flow direction X, and the odor sensor element 31M located between the sensor element 31C and the sensor element 31D were simulated sensor elements.

[0111] Comparative Example 1 will be described with reference to Fig. 9. Fig. 9 is a schematic diagram showing the configuration of an odor measuring unit 30Z according to Comparative Example 1. Note that in Fig. 9, for ease of explanation, the same reference numerals are used to designate components having the same functions as those described in the above embodiment.

[0112] The odor measurement unit 30Z adopted the configuration of the odor measurement unit 30A according to the above-described modified example. In Comparative Example 1, (i) a first relay path 340Z that relays between the first flow path (common part 50) connected to the supply source of the first gas to be measured for odor and the internal space 325, and (ii) a second relay path 350Z for discharging the target gas from the internal space, were configured differently from the odor measurement unit 30A and the first relay path 340 and second relay path 350 according to the above-described modified example. In Comparative Example 1, the configurations other than the first relay path 340Z and the second relay path 350Z were the same as those of the odor measurement unit 30A according to the above-described modified example.

[0113] In Comparative Example 1, the first relay path 340Z and the second relay path 350Z were each formed in the spacer 328 and had no bent portions. Specifically, in Comparative Example 1, the first relay path 340Z and the second relay path 350Z were flow paths extending linearly in the direction indicated by arrow L1. The first relay path 340Z and the second relay path 350Z each had an inner diameter of Φ2. That is, the size of the third opening 342Z and the fourth opening 352Z was each Φ2. The volume of the internal space 325 was 0.65 ml. The height of the internal space 325 was 3 mm. That is, the height of the spacer 328 was 3 mm.

[0114] In Comparative Example 1, the odor sensor elements 31A and 31C located most upstream in the flow direction X, and the odor sensor elements 31B and 31D located most downstream in the flow direction X, each used a sensor element equipped with an odorant receiving layer 315 containing a silicone resin. In Comparative Example 1, the odor sensor element 31M located between the odor sensor element 31A and the odor sensor element 31B in the flow direction X, and the odor sensor element 31M located between the sensor element 31C and the sensor element 31D, were simulated sensor elements.

[0115] <Method 1> Ethanol of a specific concentration was supplied to the internal space 325 via the first relay path 340, 340Z, and the waveform intensity of the measurement signal output from each odor sensor element 31 included in the odor measuring unit 30A1, 30A2, 30Z was measured. In the following description, the waveform intensity of the measurement signal output from the odor sensor element 31 may be simply referred to as "waveform intensity." The waveform intensity was measured using the headspace method. Specifically, the change (ΔV) in the voltage value (mV) before and after odorant adsorption and desorption was measured four consecutive times from the measurement signal output from the odor sensor element 31. The change (ΔV) measured the first time was subtracted from the four consecutive changes (ΔV) and the average of the three changes (ΔV) was used as the waveform intensity of the measurement signal output from each odor sensor element 31A-31D.

[0116] <Method 2> 3000 ppm ethanol was supplied to the internal space 325, and the waveform intensity of the measurement signal output from each odor sensor element 31 provided in the odor measuring units 30A1, 30A2, and 30Z was measured. The waveform intensity was measured in two patterns: (i) when ethanol was supplied via the first relay paths 340 and 340Z, and (ii) when ethanol was supplied via the second relay paths 350 and 350Z. The ratio of the waveform intensity of the measurement signal of the odor sensor element 31 measured in (i) above to the waveform intensity of the measurement signal of the odor sensor element 31 measured in (ii) above was calculated. That is, the ratio of the waveform intensity of the measurement signal measured when each odor sensor element 31A-31D was located at the most upstream position in the flow direction X to the waveform intensity of the measurement signal measured when it was located at the most downstream position in the flow direction X was calculated.

[0117] When ethanol is supplied from the second relay paths 350, 350Z, the odor sensor elements 31A, 31C are the sensor elements 31 located most downstream in the flow direction X, and the odor sensor elements 31B, 31D are the sensor elements 31 located most upstream in the flow direction X. When ethanol is supplied from the second relay paths 350, 350Z, the flow direction X is opposite to the direction of the arrow shown in Figures 8 and 9, and is from right to left on the paper.

[0118] <Results> Measurement results using Method 1 will be described with reference to FIG. 10 . FIG. 10 is a graph showing measurement results of the waveform intensity of the measurement signal output from the odor sensor elements 31A to 31D. The graph shown in FIG. 10 shows measurement results, measured using Method 1, of the waveform intensity of the measurement signal output from each of the odor sensor elements 31A to 31D of the odor measuring units 30A1, 30A2, and 30Z according to Example 1, Example 2, and Comparative Example 1. In the graph shown in FIG. 10 , the vertical axis represents the average value of the change (ΔV) in the measurement signal output from the odor sensor elements 31A to 31D, and the horizontal axis represents the odor sensor elements 31A to 31D to which the measurement signal is output. In the graph shown in FIG. 10 , the three bar graphs shown for each odor sensor element 31A to 31D represent, from left to right, the average value of the change (ΔV) in the measurement signal for Example 1, Example 2, and Comparative Example 1. The error bars shown in each bar graph represent the standard deviation of the measurement signal. The standard deviation of the measurement signal was calculated from the change (ΔV) in the measurement signal for three measurements.

[0119] 10, when the waveform intensities were evaluated, the waveform intensities of the measurement signals output from each of the odor sensor elements 31A to 31D in Example 1 were the lowest. The waveform intensities of the measurement signals output from each of the odor sensor elements 31A to 31D in Example 2 were higher than the waveform intensities of the measurement signals output from each of the odor sensor elements 31A to 31D in Example 1.

[0120] The variation in waveform intensity was evaluated. As shown by the error bars in each bar graph in FIG. 10, the variation in waveform intensity was smaller in Examples 1 and 2 than in Comparative Example 1. The value representing the variation in waveform intensity was calculated by dividing the amount of change (ΔV) in the measurement signal by the standard deviation of the measurement signal. The variation in waveform intensity in Example 1 was 1%, and the variation in waveform intensity in Example 2 was 2 to 3%. The variation in waveform intensity in Comparative Example 1 was 11 to 12%.

[0121] Next, the ratios of the waveform intensities of the measurement signals of the odor sensor elements 31A to 31D of the odor measuring units 30A1, 30A2, and 30Z according to Example 1, Example 2, and Comparative Example 1, calculated by Method 2, were evaluated. The ratios of the waveform intensities of the measurement signals of the odor sensor elements 31A to 31D of the odor measuring unit 30A1 according to Example 1 were 1.21 to 1.27. The ratios of the waveform intensities of the measurement signals of the odor sensor elements 31A to 31D of the odor measuring unit 30A2 according to Example 2 were 1.22 to 1.29. The ratios of the waveform intensities of the measurement signals of the odor sensor elements 31A to 31D of the odor measuring unit 30Z according to Comparative Example 1 were 1.32 to 1.43.

[0122] The ratio of waveform intensities calculated by Method 2 was higher in Comparative Example 1 than in Example 1 and Example 2. Therefore, it was found that in Example 1 and Example 2, the difference between the waveform intensity of the measurement signal output from the sensor element 31 located most upstream in the flow direction X and the waveform intensity of the measurement signal output from the sensor element 31 located most downstream in the flow direction X was smaller than in Comparative Example 1.

[0123] As described above, the odor measuring units 30A1 and 30A2 in Examples 1 and 2 can reduce variations in the waveform intensity of the measurement signals output from the multiple odor sensor elements 31 arranged in the internal space 325. Furthermore, it has been suggested that the odor measuring units 30A1 and 30A2 in Examples 1 and 2 can reduce the difference between the waveform intensity of the measurement signal output from the sensor element 31 located most upstream in the flow direction X in the internal space 325 and the waveform intensity of the measurement signal output from the sensor element 31 located most downstream in the flow direction X in the internal space 325. Therefore, the odor measuring units 30A1 and 30A2 in Examples 1 and 2 can reduce variations in the detection accuracy of the multiple odor sensor elements 31 arranged in the internal space 325.

[0124] [Example of Software Implementation] In the odor measuring device 100, 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.

[0125] In the latter case, the odor measuring device 100 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 loading 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.

[0126] [Summary] The measuring device of aspect 1 of the present invention comprises an odor sensor unit having a plurality of odor sensor elements that detect the odor of a target gas supplied to an internal space defined by one or more wall portions, and a first relay path having a first end connected to the wall portion at a first opening provided in the wall portion and a second end opposite the first end connected to a first flow path that is connected to a supply source of the target gas, the first relay path having at least one bend.

[0127] A measuring device according to aspect 2 of the present invention may be configured in the above-described aspect 1 so as to include a second relay path whose third end is connected to the wall portion at a second opening provided in the wall portion and for discharging the target gas from the internal space, and the second relay path may include at least one bend.

[0128] In a measuring device according to aspect 3 of the present invention, in the above-described aspect 2, the first relay path is located at the second end and has a third opening connected to the first flow path, and the second relay path is located at the fourth end and has a fourth opening connected to a second flow path for discharging the target gas from the internal space, and the third opening is an opening facing in a direction opposite to the flow direction of the target gas from the first opening to the second opening in the internal space, and the fourth opening may be an opening facing in approximately the same direction as the flow direction of the target gas from the first opening to the second opening in the internal space.

[0129] In a measuring device according to aspect 4 of the present invention, in the above-mentioned aspects 2 or 3, the first opening may be provided in a first wall portion that defines the internal space, and the second opening may be provided in the first wall portion or a second wall portion that defines the internal space and is different from the first wall portion, and both the first opening and the second opening may be openings that face in a direction that intersects with the flow direction of the target gas from the first opening to the second opening in the internal space.

[0130] In the measuring device of aspect 5 of the present invention, in any of aspects 1 to 4 above, the area of ​​a cross section perpendicular to the flow direction of the target gas in the internal space may be less than or equal to the area of ​​a cross section perpendicular to the flow direction of the target gas in the first flow path.

[0131] In the measurement device according to Aspect 6 of the present invention, in the above-mentioned Aspect 5, the area of ​​a cross section perpendicular to the flow direction of the target gas in the internal space is 600 mm ２ It may be the following:

[0132] In the measurement device of aspect 7 of the present invention, in any of aspects 1 to 6 above, the area of ​​a cross section perpendicular to the flow direction of the target gas in the first relay path may be larger than the area of ​​a cross section perpendicular to the flow direction of the target gas in the first flow path.

[0133] A measuring device according to an eighth aspect of the present invention is any one of the first to seventh aspects, wherein the plurality of odor sensor elements may be arranged along the flow direction of the target gas in the internal space.

[0134] In a measuring device according to aspect 9 of the present invention, in any one of aspects 1 to 8 above, the plurality of odor sensor elements may be provided on one or more wall portions that define the internal space.

[0135] The measuring device according to aspect 10 of the present invention may be, in any of aspects 1 to 9 above, provided with a temperature control unit that controls the temperature of at least one of the odor sensor unit and the first relay path, or at least a portion of the first flow path.

[0136] In the measuring device according to aspect 11 of the present invention, in any one of aspects 1 to 10 above, the volume of the internal space may be 0.05 ml or less per odor sensor element provided on the wall of the internal space.

[0137] 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.

[0138] 10 First supply path 20 Second supply path 30 Odor measuring section 31 Odor sensor element 65 Temperature control section 100 Odor measuring device 325 Internal space 330 Odor sensor section 340 First relay path 341 First opening 342 Third opening 343 Bent section 350 Second relay path 351 Second opening 352 Fourth opening 353 Bent section

Claims

1. An odor measuring device comprising: an odor sensor unit having a plurality of odor sensor elements that detect the odor of a target gas supplied to an internal space defined by one or more wall portions; and a first relay path having a first end connected to the wall portion at a first opening provided in the wall portion and a second end opposite the first end connected to a first flow path that is connected to a supply source of the target gas, wherein the first relay path has at least one bend.

2. The odor measuring device according to claim 1, further comprising a second relay path whose third end is connected to the wall portion at a second opening provided in the wall portion and which is used to discharge the target gas from the internal space, the second relay path having at least one bend.

3. The odor measuring device of claim 2, wherein the first relay path is located at the second end and has a third opening that connects to the first flow path, the second relay path is located at a fourth end opposite the third end and has a fourth opening that connects to a second flow path for discharging the target gas from the internal space, the third opening is an opening that faces in a direction opposite to the flow direction of the target gas from the first opening to the second opening in the internal space, and the fourth opening is an opening that faces in approximately the same direction as the flow direction of the target gas from the first opening to the second opening in the internal space.

4. An odor measuring device as described in claim 2 or 3, wherein the first opening is provided in a first wall portion that defines the internal space, the second opening is provided in the first wall portion or a second wall portion that defines the internal space and is different from the first wall portion, and both the first opening and the second opening are openings that face in a direction that intersects with the flow direction of the target gas from the first opening to the second opening in the internal space.

5. An odor measuring device described in any one of claims 1 to 4, wherein the cross-sectional area of ​​the internal space perpendicular to the flow direction of the target gas is less than or equal to the cross-sectional area of ​​the first flow path perpendicular to the flow direction of the target gas.

6. The cross-sectional area of ​​the internal space perpendicular to the flow direction of the target gas is 600 mm ２ The odor measuring device according to claim 5 , wherein:

7. An odor measuring device described in any one of claims 1 to 6, wherein the cross-sectional area of ​​the first relay path perpendicular to the flow direction of the target gas is larger than the cross-sectional area of ​​the first flow path perpendicular to the flow direction of the target gas.

8. An odor measuring device according to any one of claims 1 to 7, wherein the plurality of odor sensor elements are arranged along the flow direction of the target gas in the internal space.

9. An odor measuring device according to any one of claims 1 to 8, wherein the plurality of odor sensor elements are provided on one or more wall portions that define the internal space.

10. An odor measuring device as described in any one of claims 1 to 9, comprising a temperature control unit that controls the temperature of at least one of the odor sensor unit and the first relay path, or at least a portion of the first flow path.

11. An odor measuring device according to any one of claims 1 to 10, wherein the volume of the internal space is 0.05 ml or less per odor sensor element provided on the wall of the internal space.

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