Sensor unit

Abstract

In the present invention, humidity in a sensor unit is appropriately maintained. This sensor unit is provided with: an enclosing member having an internal space in which a living body to be measured is disposed; a moisture absorption / desorption member disposed in the internal space; and a sensor that is disposed in the internal space and that performs predetermined measurement. The enclosing member includes a passage communicating from the internal space to the outside of the enclosing member.

Description

Sensor Unit

[0001] The present invention relates to a sensor unit.

[0002] Patent Literature 1 discloses a plant biosensor capable of measuring environmental and biometric information of a plant. For example, a sap flow sensor calculates the sap flow rate of a plant by heating the plant's stem with a heater and measuring the heat transfer caused by the sap flow with a temperature sensor. For this reason, conventional sensors employ a sealed structure in which the stem and heater are enclosed in a thermally insulating housing to prevent the heat generated by the heater from escaping to the surrounding area of ​​the plant.

[0003] Japanese Patent Application Laid-Open No. 2021-69353

[0004] As in Patent Document 1, when measuring a living body in a close contact state or in an enclosed space, humidity builds up in the internal space, creating problems specific to living bodies. For example, in a plant such as a tomato, sap evaporates from the surface of the stem, increasing humidity inside the housing. Condensation forms inside the housing, creating water between the plant and the inner wall of the housing. If water remains inside the housing for a long time without evaporating, the plant's aerial roots may grow, creating gaps between the temperature sensor or heater and the plant. In such cases, the measurement results are affected and the pressure from the water or aerial roots can deteriorate or destroy the fixed sensor or heater itself. Furthermore, water acts as a medium, creating a path for heat diffusion and transfer, which can affect the measurement results and deviate from the original premise of temperature measurement. Alternatively, in the case of the human body, increased humidity in the internal space can cause discomfort to the user and reduce usability.

[0005] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to maintain an appropriate humidity level inside a sensor unit.

[0006] The present invention provides a sensor unit comprising an enclosure member having an internal space in which a living body to be measured is placed, a moisture absorbing and releasing member disposed in the internal space, and at least one sensor disposed in the internal space for performing a predetermined measurement, the enclosure member having a passageway leading from the internal space to the outside of the enclosure member. This configuration maintains an appropriate humidity level within the sensor unit. This prevents condensation and water from forming within the sensor unit due to high humidity levels within the sensor unit. Maintaining an appropriate humidity level within the sensor unit allows the sensor to perform measurements stably over a long period of time.

[0007] The sensor unit may further include a permeable member disposed in the passage and connected to the moisture absorbing and releasing member. The moisture absorbed by the moisture absorbing and releasing member permeates the permeable member, thereby preventing water from accumulating within the sensor unit and maintaining an appropriate humidity level within the sensor unit.

[0008] A portion of the permeable member may be disposed outside the enclosing member. By disposing a portion of the permeable member outside the enclosing member, it is possible to release a large amount of moisture outside the enclosing member.

[0009] The permeation member may have a first portion disposed in the passage and a second portion disposed outside the enclosing member, and the second portion of the permeation member may be formed to extend outward beyond the passage. By forming the second portion of the permeation member to extend outward beyond the passage leading from the internal space to the outside of the enclosing member, a large amount of moisture can be released outside the enclosing member.

[0010] The enclosing member may have lower moisture permeability than the permeable member. Even if the enclosing member has lower moisture permeability than the permeable member, the humidity inside the sensor unit can be maintained at an appropriate level. The permeable member may be a member having moisture absorption and release properties.

[0011] The sensor unit may include a moisture-permeable member that is moisture-permeable and that is provided to cover the path from the passage to the outside air. The moisture-permeable member has the function of allowing moisture to pass through but not allowing water or wind to pass through and blocking heat. By covering the path from the passage to the outside air, which is the air outside the sensor unit, with the moisture-permeable member, the intrusion of water, wind, and heat from the outside of the sensor unit into the inside of the sensor unit is prevented. The moisture-permeable member may also have the function of allowing moisture to pass from one direction to another but not allowing moisture to pass from the other direction to one direction. Moisture may pass through the moisture-permeable member from inside the sensor unit to the outside of the sensor unit, but moisture may not pass through the moisture-permeable member from the outside of the sensor unit to the inside of the sensor unit.

[0012] The enclosing member may have lower moisture permeability than the moisture permeable member. Even if the enclosing member has lower moisture permeability than the moisture permeable member, the humidity inside the sensor unit can be maintained at an appropriate level.

[0013] The at least one sensor may be a temperature sensor for measuring temperature. The sensor unit may include a heater disposed in the internal space. The enclosure member may include a heat insulating material disposed so as to surround the internal space. The living organism to be measured may be a plant.

[0014] According to the present invention, the humidity inside the sensor unit can be maintained at an appropriate level.

[0015] Fig. 1 is a diagram showing a schematic view of the overall configuration of the measurement device. Fig. 2 shows the configuration of the measurement device. Fig. 3 is a perspective view of a sensor unit. Fig. 4 is a cross-sectional view of the sensor unit. Fig. 5 is a cross-sectional view of the sensor unit. Fig. 6 is a diagram showing a state in which a thin film is in close contact with a plant stem. Fig. 7 is a diagram showing a state in which a thin film is in close contact with a plant stem. Fig. 8 is a diagram showing a state in which the thin film is unfolded and stretched.

[0016] Application examples and embodiments will be described below with reference to the drawings. The application examples and embodiments described below are aspects of the present application and do not limit the scope of the rights of the present application.

[0017] <Application Example> The present invention can be applied to, for example, a measuring device 1 shown in FIG. 1 . FIG. 1 is a diagram schematically illustrating the overall configuration of the measuring device 1. The measuring device 1 includes a sensor unit (sensor head) 10, a controller 20, and a cable 30. The sensor unit 10 is capable of gripping or clamping a predetermined portion (measurement target), such as a stem or branch, of a plant (crop) 2 being cultivated. The plant 2, which is the living organism being measured, is, for example, a tomato, but is not limited to tomatoes and may be other plants. For example, the sensor unit 10 measures the temperature of the plant 2 and sends the measurement data to the controller 20. The controller 20 is a device that controls the entire measuring device 1 and performs arithmetic processing based on the measurement data of the sensor unit 10. The cable 30 has power wiring and signal wiring. The controller 20 supplies power to the sensor unit 10 via the cable 30. The controller 20 also sends control signals to the sensor unit 10 and acquires measurement data from the sensor unit 10 via the cable 30.

[0018] FIG. 2 is a configuration diagram of the measurement device 1. The sensor unit 10 includes a heater 11, a constant current circuit 13, temperature sensors 14 to 17, an amplifier 18, and an analog-to-digital converter (ADC) 19. The controller 20 includes a microcomputer 21 and a constant voltage source 22. The heater 11 is a heating device that heats the plant 2 to which the sensor unit 10 is attached. The temperature of the heater 11 increases when a constant voltage is applied to the heater 11 from the constant voltage source 22. The constant current circuit 13 controls the current input to the heater 11 to be constant. The temperature sensors 14 to 17 measure the temperature of the plant 2 to which the sensor unit 10 is attached. The amplifier 18 amplifies the signals output from the temperature sensors 14 to 17. The analog-to-digital converter 19 converts analog signals into digital signals. The microcomputer 21 may be configured, for example, by a computer including a processor such as a CPU (Central Processing Unit), a memory as a main storage device, and a storage device as an auxiliary storage device.

[0019] <Embodiment> Fig. 3 is a perspective view of sensor unit 10. Figs. 4 and 5 are cross-sectional views of sensor unit 10. Fig. 5 is a cross-sectional view taken along line A-A in Fig. 4. Sensor unit 10 has an outer jacket (first housing) 101, an inner jacket (second housing) 102, a heat insulating material 103, a thin film 104, a humidity control member 105, a humidity permeable member 106, elastic members 107 and 108, and an opening / closing member 109.

[0020] The outer jacket 101 is a member that forms the exterior of the sensor unit 10. The outer jacket 101 functions as a light-shielding member that prevents sunlight (e.g., infrared components) from entering the interior of the sensor unit 10 from the outside. The outer jacket 101 also functions as a heat-shielding member that prevents heat from being transferred from the outside to the interior of the sensor unit 10. The outer jacket 101 also functions as a waterproof member that prevents water from entering the interior of the sensor unit 10 from the outside. A heat insulating material 103 is disposed inside the outer jacket 101. The heat insulating material 103 is an example of an enclosure member that is disposed to surround the plant 2, and insulates the heat generated by the heater 11 from escaping to the outside of the outer jacket 101. The heat insulating material 103 is, for example, a fiber-based insulation material or a foamed plastic-based insulation material. Examples of fiber-based insulation materials include inorganic fiber-based insulation materials such as rock wool and glass wool, and wood fiber-based insulation materials such as cellulose fiber and insulation board. Examples of expanded plastic insulating materials include urethane foam, bead-method polystyrene foam, extruded polystyrene foam, polyethylene foam, and phenolic foam. The insulating material 103 may also be part of an enclosure member. That is, an enclosure member including the insulating material 103 may be arranged to surround the plant 2. The insulating material 103 has a cylindrical shape, and the inner jacket 102, the thin film 104, and the humidity control member 105 are arranged inside the insulating material 103. In other words, the insulating material 103 is arranged to surround the inner jacket 102, the thin film 104, and the humidity control member 105.

[0021] The inner jacket 102 secures the thin film 104 in close contact with the stem (e.g., main stem) of the plant 2. The inner jacket 102 is composed of two curved members facing each other, with the stem of the plant 2 passing between the two curved members. That is, the central portion of the inner jacket 102 is hollow, and the stem of the plant 2 can be inserted into this hollow central portion of the inner jacket 102. When the sensor unit 10 is attached to the stem of the plant 2, the inner jacket 102 is positioned to surround the stem of the plant 2 and holds the plant 2, which is the target object. The inner jacket 102 is an example of a holding member.

[0022] 6 and 7 are diagrams showing the state in which the thin film 104 is attached to the inner jacket 102 and is in close contact with the stem of the plant 2. Fig. 6 is a cross-sectional view seen from the growing direction of the stem of the plant 2, and Fig. 7 is a cross-sectional view seen from a direction perpendicular to the growing direction of the stem of the plant 2. Fig. 8 is a diagram showing the thin film 104 in an unfolded and stretched state. The thin film 104 has a heater 11.

[0023] The heater 11 is, for example, a copper wire pattern formed on the thin film 104. The heater 11 transfers a desired amount of heat to the stem of the plant 2. By providing the thin film 104 inside the inner jacket 102, the heater 11 is disposed inside the inner jacket 102. When the sensor unit 10 is attached to the stem of the plant 2, the heater 11 is disposed between the stem of the plant 2 and the inner jacket 102. By bringing the thin film 104 into close contact with the stem of the plant 2, the heater 11 also comes into close contact with the stem of the plant 2, and heat from the heater 11 is efficiently transferred to the stem of the plant 2.

[0024] Temperature sensors 14 to 17 are attached to the inner jacket 102. The temperature sensors 14 to 17 are temperature measuring elements such as thermistors, and perform predetermined measurements. When the sensor unit 10 is attached to the stem of the plant 2, the temperature sensors 14 to 16 are disposed inside the inner jacket 102, and the temperature sensor 17 is disposed outside the inner jacket 102. When the sensor unit 10 is attached to the stem of the plant 2, the temperature sensors 14 to 16 are disposed between the stem of the plant 2 and the inner jacket 102. The thin film 104 comes into close contact with the stem of the plant 2, so that the temperature sensors 14 to 16 come into close contact with the stem of the plant 2, and the temperature sensors 14 to 16 accurately measure the temperature of the stem of the plant 2.

[0025] When the sensor unit 10 is attached to the stem of the plant 2, the temperature sensors 14 and 15 are arranged along the growth direction of the stem of the plant 2. Therefore, the temperature sensors 14 and 15 measure the temperatures at any two points in the growth direction of the stem of the plant 2. When the sensor unit 10 is attached to the stem of the plant 2, the temperature sensors 16 and 17 are arranged along the radial direction of the stem of the plant 2. Therefore, the temperature sensors 16 and 17 measure the temperatures at any two points in the radial direction of the stem of the plant 2. The temperature sensor 16 measures the temperature inside the inner jacket 102, and the temperature sensor 17 measures the temperature outside the inner jacket 102.

[0026] The controller 20 measures the sap flow rate of the plant 2. The controller 20 may measure the sap flow rate of the plant 2 using a stem heat balance method. The stem of the plant 2 is heated by a heater 11, and the heat transfer of the sap flow of the plant 2 is measured by temperature sensors 14 to 17. The controller 20 measures the sap flow rate of the plant 2 based on the temperature data measured by the temperature sensors 14 to 17. When the stem of the plant 2 is heated by the heater 11, the temperature of the sap flowing through the stem of the plant 2 increases, and the measured temperatures of the temperature sensors 14 to 17 change. The controller 20 measures the sap flow rate of the plant 2 from the change in the measured temperatures of the temperature sensors 14 to 17. The controller 20 may measure the sap flow rate of the plant 2 using a method other than the stem heat balance method. The controller 20 may store the sap flow rate data of the plant 2 in its own memory or storage, or in an external storage device connected to the controller 20. The controller 20 may also send the sap flow rate data of the plant 2 to an information processing device such as a personal computer via a communication interface.

[0027] The thermal insulation material 103 has an internal space (first space) 121. Arranged in the internal space 121 are the plant 2, the inner jacket 102, the thin film 104 provided with the heater 11 and the temperature sensors 14 to 17, and part of the humidity control member 105. The thermal insulation material 103 is arranged to surround the internal space 121. The thermal insulation material 103 has a passage 122 that leads from the internal space 121 to the outside of the thermal insulation material 103. The passage 122 may be, for example, a through-hole, a slit, a gap, or an opening that penetrates the thermal insulation material 103 from one side (exterior side) of the thermal insulation material 103 to the other side (interior side).

[0028] The humidity control member 105 is a sheet member having moisture absorption and release properties. The humidity control member 105 absorbs moisture generated by the plant 2 and releases the absorbed moisture. The humidity control member 105 is disposed on the outside of the inner jacket 102 so as to wrap around the stem of the plant 2. The humidity control member 105 has a cylindrical portion 131, the inside of which is designed to allow the stem of the plant 2 to be inserted. The humidity control member 105 has a curved portion 132 connected to the cylindrical portion 131. The cylindrical portion 131 of the humidity control member 105 is disposed in the internal space 121. More specifically, the cylindrical portion 131 of the humidity control member 105 is disposed between the inner jacket 102 and the thermal insulation 103 so as to surround the plant 2. The curved portion 132 of the humidity control member 105 is disposed in a passage 122 leading from the internal space 121 to the outside of the thermal insulation 103. The bent portion 132 of the humidity control member 105 passes through the passage 122 of the heat insulating material 103 and covers part of the outside of the heat insulating material 103. That is, part of the bent portion 132 of the humidity control member 105 is inserted into the passage 122 of the heat insulating material 103, and another part of the bent portion 132 of the humidity control member 105 is disposed outside the heat insulating material 103.

[0029] A hole 110 is formed in the outer jacket 101. The hole 110 may be, for example, a through-hole, a slit, a gap, or an opening that penetrates the outer jacket 101 from one side (outer side) of the outer jacket 101 to the other side (inner side) of the outer jacket 101. The sensor unit 10 may have an external space (second space) 123 connected to the passage 122. In the configuration examples shown in FIGS. 4 and 5 , the sensor unit 10 has the external space 123, but the configuration is not limited to the examples shown in FIGS. 4 and 5 , and the external space 123 may be omitted from the sensor unit 10. If the sensor unit 10 does not have the external space 123, a portion of the inner surface of the outer jacket 101 and a portion of the bent portion 132 of the humidity control member 105 are in contact with each other. Part or all of the path from the passage 122 to the outside air may overlap with a portion of the external space 123. The outside air is air outside the sensor unit 10. Another part of the bent portion 132 of the humidity control member 105 may be disposed in the external space 123. The bent portion 132 of the humidity control member 105 has a first portion disposed in the passage 122 and a second portion disposed outside the thermal insulation material 103. The second portion of the bent portion 132 of the humidity control member 105 is formed to extend outward beyond the passage 122 of the thermal insulation material 103.

[0030] The cylindrical portion 131 of the humidity control member 105 functions as a moisture absorbing and desorbing member that absorbs moisture in the internal space 121. The portion of the humidity control member 105 that functions as a moisture absorbing and desorbing member is, for example, silica gel. The moisture absorbed by the cylindrical portion 131 of the humidity control member 105 permeates and diffuses throughout the cylindrical portion 131 of the humidity control member 105. The cylindrical portion 131 of the humidity control member 105 then transports the moisture to the bent portion 132 of the humidity control member 105, and the moisture is propagated to the bent portion 132 of the humidity control member 105. The bent portion 132 of the humidity control member 105 functions as a permeating member. The moisture absorbed by the cylindrical portion 131 of the humidity control member 105 permeates into the bent portion 132 of the humidity control member 105. Moisture in the internal space 121 is absorbed by the cylindrical portion 131 of the humidity control member 105 and penetrates the bent portion 132 of the humidity control member 105, thereby preventing water from accumulating within the sensor unit 10 and maintaining an appropriate humidity level within the sensor unit 10. The moisture that penetrates the bent portion 132 of the humidity control member 105 is released from the bent portion 132 of the humidity control member 105 and is released into the outside air through the hole 110 of the outer jacket 101. This allows the moisture absorbed by the cylindrical portion 131 of the humidity control member 105 to constantly penetrate the bent portion 132 of the humidity control member 105. Therefore, the humidity level within the sensor unit 10 can be maintained at an appropriate level for a long period of time. By disposing the second portion of the bent portion 132 of the humidity control member 105 outside the thermal insulation 103, a large amount of moisture can be released into the outside air. By forming the second portion of the bent portion 132 of the humidity control member 105 to extend outward beyond the passage 122 of the heat insulating material 103, a large amount of moisture can be released into the outside air.

[0031] The cylindrical portion 131 and the curved portion 132 of the humidity control member 105 may be integral, or the cylindrical portion 131 and the curved portion 132 of the humidity control member 105 may be separate. Both the cylindrical portion 131 and the curved portion 132 of the humidity control member 105 may be sheet members, or one of the cylindrical portion 131 and the curved portion 132 of the humidity control member 105 may be a sheet member. By using a sheet member for at least one of the cylindrical portion 131 and the curved portion 132 of the humidity control member 105, the humidity control member 105 can be flexibly positioned, enabling the sensor unit 10 to be miniaturized. The cylindrical portion 131 of the humidity control member 105 may be made of a material that has higher moisture absorption than the curved portion 132 of the humidity control member 105. The curved portion 132 of the humidity control member 105 may be made of a material that has at least one of moisture permeability, diffusibility, transportability, and release properties higher than the cylindrical portion 131 of the humidity control member 105.

[0032] The moisture permeable member 106 is provided so as to cover the path leading from the passage 122 of the thermal insulation material 103 to the outside air. For example, the moisture permeable member 106 may be provided in the outer jacket 101 so as to cover the hole 110 formed in the outer jacket 101. In the configuration example shown in FIGS. 4 and 5 , the moisture permeable member 106 is provided inside the outer jacket 101 so as to cover the hole 110 of the outer jacket 101 from the inside of the outer jacket 101. Without being limited to the configuration example shown in FIGS. 4 and 5 , the moisture permeable member 106 may be provided outside the outer jacket 101 so as to cover the hole 110 of the outer jacket 101 from the outside of the outer jacket 101. The moisture permeable member 106 may be provided inside the hole 110 of the outer jacket 101.

[0033] The moisture-permeable member 106 is a moisture-permeable sheet member. The moisture-permeable member 106 has the function of allowing moisture to pass through but not allowing water or wind to pass through and blocking heat. Covering the holes 110 in the outer jacket 101 with the moisture-permeable member 106 prevents water, wind, and heat from entering the interior of the sensor unit 10 through the holes 110 in the outer jacket 101. The moisture-permeable member 106 may also have the function of allowing moisture to pass from one direction to another but not allowing moisture to pass from the other direction to one direction. Moisture may pass through the moisture-permeable member 106 from inside the sensor unit 10 to the outside of the sensor unit 10, but moisture may not pass through the moisture-permeable member 106 from the outside of the sensor unit 10 to the inside of the sensor unit 10. One hole 110 may be formed in the outer jacket 101, or multiple holes 110 may be formed in the outer jacket 101. A plurality of moisture permeable members 106 may be provided in the outer jacket 101, and each of the moisture permeable members 106 may cover a plurality of holes 110 in the outer jacket 101. Also, at least one of the plurality of holes 110 in the outer jacket 101 may be covered by the moisture permeable member 106. The positions of the holes 110 formed in the outer jacket 101 are not particularly limited. In the configuration examples shown in Figures 4 and 5, the moisture permeable members 106 are provided in the outer jacket 101, but the configuration is not limited to the examples shown in Figures 4 and 5, and the provision of the moisture permeable members 106 in the outer jacket 101 may be omitted.

[0034] Various materials can be used as the material for the heat insulating material 103. For example, the heat insulating material 103 may be a material having lower moisture permeability than the humidity control member 105 and the moisture permeable member 106. Even if the heat insulating material 103 is a material having lower moisture permeability than the humidity control member 105 and the moisture permeable member 106, it is possible to maintain an appropriate humidity level inside the sensor unit 10. Furthermore, the outer jacket 101 may be a material having lower moisture permeability than the heat insulating material 103. Even if the outer jacket 101 is a material having lower moisture permeability than the heat insulating material 103, it is possible to maintain an appropriate humidity level inside the sensor unit 10.

[0035] Moisture in the internal space 121 is absorbed by the cylindrical portion 131 of the humidity control member 105 and released into the outside air from the bent portion 132 of the humidity control member 105. The humidity control member 105 exhibits greater moisture absorption capacity as the humidity in the internal space 121 increases, and releases the absorbed moisture when the humidity in the internal space 121 decreases, thereby controlling the humidity in the internal space 121. This maintains an appropriate humidity level within the sensor unit 10. This prevents condensation caused by an increase in humidity within the sensor unit 10 and prevents water from forming within the sensor unit 10, thereby suppressing the growth of aerial roots.

[0036] By maintaining an appropriate humidity level within the sensor unit 10, the measuring device 1 can stably measure the sap flow rate of the plant 2 over a long period of time. Furthermore, since there is no need to remove aerial roots during maintenance of the sensor unit 10, the labor required is reduced. Furthermore, since deterioration and damage to the temperature sensors 14 to 17 and the heater 11 are prevented, the lifespan of the sensor unit 10 is extended, resulting in cost improvements.

[0037] This allows the inside of the sensor unit 10 to dry easily in case of intrusion of chemicals into the sensor unit 10 when spraying pesticides or intrusion of rain into the sensor unit 10 when used outdoors. In addition, since water is prevented from accumulating inside the sensor unit 10, it is possible to prevent the occurrence of pests and diseases in the plants 2.

[0038] 4 and 5 , the hole 110 of the outer jacket 101 and a part of the bent portion 132 of the humidity control member 105 face each other. That is, the hole 110 of the outer jacket 101 and a part of the bent portion 132 of the humidity control member 105 overlap in the radial direction of the stem of the plant 2. The hole 110 of the outer jacket 101 and a part of the bent portion 132 of the humidity control member 105 facing each other makes it easier for moisture released from the bent portion 132 of the humidity control member 105 to pass through the hole 110 of the outer jacket 101, thereby facilitating moisture release to the outside air. The sensor unit 10 is not limited to the exemplary configuration shown in FIGS. 4 and 5 , and may have a configuration in which the hole 110 of the outer jacket 101 and the bent portion 132 of the humidity control member 105 do not face each other.

[0039] As shown in Figures 4 and 5, a portion of the bent portion 132 of the humidity control member 105 faces the moisture-permeable member 106. That is, a portion of the bent portion 132 of the humidity control member 105 overlaps the moisture-permeable member 106 in the radial direction of the stem of the plant 2. The hole 110 of the outer jacket 101 faces a portion of the bent portion 132 of the humidity control member 105, and a portion of the bent portion 132 of the humidity control member 105 faces the moisture-permeable member 106. This allows moisture released from the bent portion 132 of the humidity control member 105 to easily pass through the hole 110 of the outer jacket 101, and prevents water, wind, and heat from coming into direct contact with the humidity control member 105 through the hole 110 of the outer jacket 101. The sensor unit 10 is not limited to the exemplary configuration shown in Figures 4 and 5, and may have a configuration in which the bent portion 132 of the humidity control member 105 does not face the moisture-permeable member 106.

[0040] In the configuration example shown in Figures 4 and 5, the humidity control member 105 and the humidity permeable member 106 are spaced apart. That is, a space exists between the humidity control member 105 and the humidity permeable member 106. The configuration example is not limited to that shown in Figures 4 and 5, and the humidity control member 105 and the humidity permeable member 106 may be in contact with each other. For example, the humidity permeable member 106 may be attached to the bent portion 132 of the humidity control member 105. Whether the humidity control member 105 and the humidity permeable member 106 are in contact with each other or not, moisture released from the bent portion 132 of the humidity control member 105 is released to the outside air through the holes 110 in the outer jacket 101.

[0041] The elastic members 107 and 108 are formed of, for example, a rubber material. The elastic member 107 prevents heat and water from entering the interior of the sensor unit 10 from the portion of the sensor unit 10 where the stem of the plant 2 is inserted. The elastic member 108 prevents heat and water from entering the interior of the sensor unit 10 from the portion of the sensor unit 10 where the cable 30 is inserted.

[0042] The opening / closing member 109 is attached to the outer jacket 101. The opening / closing member 109 rotates around a rotation shaft 111 of the opening / closing member 109. The tip of the opening / closing member 109 is hook-shaped, and the rotation shaft 111 is provided at the rear end of the opening / closing member 109. By hooking the tip of the opening / closing member 109 onto a protrusion 112 of the outer jacket 101, a first portion (upper portion) of the outer jacket 101 and a second portion (lower portion) of the outer jacket 101 are fixed together, and the outer jacket 101 can be closed. By removing the tip of the opening / closing member 109 from the protrusion 112 of the outer jacket 101, the first and second portions of the outer jacket 101 move around the rotation shaft 113 of the outer jacket 101. As a result, the first portion of the outer jacket 101 and the second portion of the outer jacket 101 are separated from each other, and the outer jacket 101 can be opened.

[0043] With the outer jacket 101 open, the stems of the plant 2, the inner jacket 102, the heat insulating material 103, the thin film 104, the humidity control member 105, etc. are placed inside the outer jacket 101, and the outer jacket 101 is closed. The heat insulating material 103 can be divided into multiple pieces. The stems of the plant 2, the inner jacket 102, the thin film 104, the humidity control member 105, etc. may be placed inside the outer jacket 101 with the multiple divided pieces of the heat insulating material 103 in close contact with the inner surface of the outer jacket 101. The humidity control member 105 can be divided into multiple pieces. When placing the humidity control member 105 inside the outer jacket 101, the multiple divided pieces of the humidity control member 105 may be in close contact with the heat insulating material 103. A portion (e.g., an upper portion) of the heat insulating material 103, an upper portion of the cylindrical portion 131, and a bent portion 132 of the humidity control member 105 may be removably fixed to a first portion (upper portion) of the outer jacket 101. Another portion (for example, the lower portion) of the heat insulating material 103 and the lower portion of the cylindrical portion 131 of the humidity control member 105 may be removably fixed to a second portion (lower portion) of the outer jacket 101 .

[0044] (Others) The above-described embodiment merely exemplifies the configuration of the present invention. The present invention is not limited to the specific embodiment described above, and various modifications are possible within the scope of the technical concept.

[0045] In the above embodiment, the non-invasive heater 11 and the non-invasive temperature sensors 14 to 17 are used, but this is not limiting. Invasive heaters 11 and invasive temperature sensors 14 to 17 may also be used. For example, when the non-invasive heater 11 and the non-invasive temperature sensors 14 to 17 are used, heating by the heater 11 and temperature measurements by the temperature sensors 14 to 17 are performed without inserting the heater 11 and the temperature sensors 14 to 17 into the stem of the plant 2. For example, when the invasive heater 11 and the invasive temperature sensors 14 to 17 are used, heating by the heater 11 and temperature measurements by the temperature sensors 14 to 17 are performed by inserting the heater 11 and the temperature sensors 14 to 17 into the stem of the plant 2.

[0046] In the above embodiment, the sensor unit 10 is attached to the stem of the plant 2, and the controller 20 measures the sap flow rate of the plant 2. However, this is not limiting. The sensor unit 10 may be attached to the arm of a living body (e.g., a human) to be measured, and the controller 20 may measure at least one of blood pressure and pulse rate. In this case, the sensor unit 10 may be provided with at least one of a blood pressure sensor and a pulse rate sensor instead of the heater 11 and the temperature sensors 14-17, and the controller 20 acquires measurement data measured by the at least one of the blood pressure sensor and the pulse rate sensor from the sensor unit 10. The measurement data includes at least one of blood pressure data and pulse rate data. Since the humidity inside the outer jacket 101 is maintained at an appropriate level, the measurement device 1 can stably measure blood pressure and pulse rate over a long period of time. Furthermore, since deterioration and damage of the temperature sensors 14-17 and the heater 11 are prevented, the lifespan of the sensor unit 10 is extended, resulting in cost savings.

[0047] The measuring device 1 may include predetermined devices and apparatuses for measuring blood pressure or pulse rate. The controller 20 may store the measurement data in its own memory or storage, or in an external storage device connected to the controller 20. The controller 20 may also send the measurement data to an information processing device such as a personal computer via a communication interface. The controller 20 may also be disposed within the sensor unit 10. The measuring device 1 may also be a wearable device in which the sensor unit 10 and the controller 20 are integrated.

[0048] <Supplementary Note 1> A sensor unit (10) comprising: an enclosure member (103) having an internal space (121) in which a living body to be measured is placed; a moisture absorbing and desorbing member (131) placed in the internal space (121); and at least one sensor placed in the internal space (121) for performing a predetermined measurement, wherein the enclosure member (103) has a passage (122) leading from the internal space (121) to the outside of the enclosure member (100). <Supplementary Note 2> The sensor unit (10) according to Supplementary Note 1 comprises a permeation member (132) placed in the passage (122) and connected to the moisture absorbing and desorbing member (131). <Supplementary Note 3> The sensor unit (10) according to Supplementary Note 2, wherein a portion of the permeation member (132) is placed outside the enclosure member (103). <Supplementary Note 4> The sensor unit (10) according to Supplementary Note 3, wherein the permeable member (132) has a first portion disposed in the passage (122) and a second portion disposed outside the enclosing member (103), and the second portion of the permeable member (132) is formed to extend outward beyond the passage (122). <Supplementary Note 5> The sensor unit (10) according to any one of Supplements 2 to 4, wherein the enclosing member (103) has lower moisture permeability than the permeable member (132). <Supplementary Note 6> The sensor unit (10) according to any one of Supplements 2 to 5, wherein the permeable member (132) is a member having moisture absorption and release properties. <Supplementary Note 7> The sensor unit (10) according to any one of Supplements 1 to 6, wherein the sensor unit (10) includes a moisture-permeable member (106) that is provided to cover a path from the passage (122) to the outside air. <Supplementary Note 8> The sensor unit (10) according to Supplementary Note 7, wherein the enclosing member (103) has lower moisture permeability than the moisture-permeable member (106). <Supplementary Note 9> The sensor unit (10) according to any one of Supplements 1 to 8, wherein the at least one sensor is a temperature sensor (14-17) that measures temperature. <Supplementary Note 10> The sensor unit (10) according to any one of Supplements 1 to 9, further comprising a heater (11) arranged in the internal space (121).<Supplementary Note 11> The sensor unit (10) according to any one of Supplementary Notes 1 to 10, wherein the enclosing member (103) includes a heat insulating material (103) arranged to surround the internal space (121). <Supplementary Note 12> The sensor unit (10) according to any one of Supplementary Notes 1 to 11, wherein the living organism to be measured is a plant (2).

[0049] 1: Measuring device 2: Plant 10: Sensor unit 11: Heater 14-17: Temperature sensors 20: Controller 101: Outer jacket 102: Inner jacket 103: Heat insulating material 104: Thin film 105: Humidity conditioning member 106: Moisture permeable member 110: Hole 121: Internal space 122: Passage 123: External space 131: Cylindrical portion 132: Bent portion

Claims

1. A sensor unit comprising: an enclosing member having an internal space in which a living body to be measured is placed; a moisture absorbing and releasing member placed in said internal space; and at least one sensor placed in said internal space for performing a specified measurement, said enclosing member having a passage leading from said internal space to the outside of said enclosing member.

2. The sensor unit according to claim 1, further comprising a permeable member disposed in the passage and connected to the moisture absorbing and releasing member.

3. The sensor unit according to claim 2, wherein a portion of the permeable member is disposed outside the enclosing member.

4. A sensor unit as described in claim 3, wherein the permeation member has a first portion disposed in the passage and a second portion disposed outside the enclosing member, and the second portion of the permeation member is formed to extend outward beyond the passage.

5. The sensor unit according to claim 2, wherein the enclosing member has a lower moisture permeability than the permeable member.

6. The sensor unit according to any one of claims 2 to 5, wherein the permeable member is a member having moisture absorbing and releasing properties.

7. The sensor unit according to claim 1, further comprising a moisture-permeable member that is permeable to moisture and is arranged to cover the path from the passage to the outside air.

8. The sensor unit according to claim 7, wherein the enclosing member has lower moisture permeability than the moisture permeable member.

9. The sensor unit according to claim 1, wherein the at least one sensor is a temperature sensor for measuring temperature.

10. The sensor unit according to claim 1, further comprising a heater disposed in the internal space.

11. The sensor unit according to claim 1, wherein the enclosure member includes a thermal insulator arranged to surround the internal space.

12. The sensor unit according to claim 1, wherein the living body to be measured is a plant.

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