Temperature measuring device

Abstract

To measure the surface temperature of a non-heat-generating body in a room accurately.SOLUTION: A temperature measurement device 10 for air conditioning that is installed in a room 90 includes a housing 20, a sensor device 30, a circuit board 40, and a fan 60. The housing 20 houses the sensor device 30, the circuit board 40, and the fan 60. The sensor device 30 includes a temperature difference sensor 33n that has a reference contact point and a temperature contact point heated by an infrared ray from a measurement object 95n in a room 90, and converts the temperature difference between the reference contact point and the temperature contact point into electromotive force, and a contact type temperature sensor 34 that detects the temperature of the reference contact point. The circuit board 40 derives the surface temperature of the measurement object 95n on the basis of the electromotive force converted by the temperature difference sensor 33n and the temperature at the reference contact point detected by the temperature sensor 34. The fan 60 generates wind F that makes the heat generated from the circuit board 40 go away from the sensor device 30. By the wind F, the heat of the circuit board 40 is exhausted out of the housing 20 through an exhaust port H2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a temperature measuring device for air conditioning that measures the surface temperature of a measurement object indoors. [Background technology]

[0002] As a temperature measuring device for air conditioning, Patent Document 1 discloses a temperature measuring device that is installed in a room and measures the surface temperatures of objects such as walls, floors, desks, personal computers, and people inside the room using infrared rays from the objects. The measured surface temperatures are sent to an air conditioning system and used for controlling the room by the air conditioning system.

[0003] A conventional temperature measuring device for air conditioning includes a sensor device, a circuit board, and a housing that houses them. The sensor device has a reference junction and a hot junction that is heated by infrared rays from an object to be measured, and is provided with a temperature difference sensor that converts the temperature difference between them into an electromotive force V. The sensor device is further provided with a contact-type temperature sensor that detects a reference temperature Tc that is the temperature of the reference junction. The circuit board derives a measurement object temperature Tt, which is the surface temperature of the object to be measured, based on the electromotive force V converted by the temperature difference sensor and the reference temperature Tc detected by the temperature sensor.

[0004] Here, the above-mentioned measurement target temperature Tt, reference temperature Tc, and electromotive force V have a relationship represented by the following formula (1): where α is a coefficient, which is obtained in advance by an experiment or the like. V = α(Tt 4 -Tc 4 ) · · · (1)

[0005] The circuit board of the temperature measuring device derives the temperature to be measured Tt based on the reference temperature Tc and the electromotive force V, using the following formula (2) which is a modification of the above formula (1). Tt= 4 √(V / α+Tc 4 ) · · · (2) [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2020-56546 A Summary of the Invention [Problem to be solved by the invention]

[0007] The inventors of the present application have conducted various studies on the above-mentioned temperature measuring device, and as a result have found the following problems, which have led to the invention of the present application. These problems will be described in detail below.

[0008] First, referring to the above formulas (1) and (2), when the electromotive force V=0, that is, when the reference temperature Tc and the measurement target temperature Tt are equal, the coefficient α has no effect on the derivation of the measurement target temperature Tt. Conversely, the larger the absolute value of the electromotive force V, the greater the effect of α on the derived measurement target temperature Tt. Here, the reference temperature Tc is detected with a contact-type temperature sensor, so it is detected with relatively high accuracy. On the other hand, the coefficient α is calculated based on experimental results, etc., but is affected by various factors, so it is difficult to express it correctly. In other words, an error is inevitably generated in the coefficient α. For these reasons, if the reference temperature Tc is brought close to the measurement target temperature Tt and the electromotive force V is reduced, the effect of the coefficient α on the measurement target temperature Tt is reduced, and as a result, the measurement accuracy of the measurement target temperature Tt is improved.

[0009] Here, the measurement target of the temperature measuring device for air conditioning is an object in the room as described above, including a non-heating object such as a floor, a desk, or a wall. When the surface temperature of the non-heating object and the room temperature are in equilibrium, the two are almost the same temperature, so if the reference temperature Tc is close to the room temperature, this reference temperature Tc is close to the measurement target temperature Tt, which is the surface temperature of the non-heating object as the measurement target. Therefore, in this case, the measurement accuracy of the measurement target temperature Tt is good. Here, most of the objects in the room are non-heating objects such as floors, walls, desks, and bookshelves. Furthermore, since people in the room are more sensitive to changes in room temperature in the above-mentioned equilibrium state than when the room temperature changes suddenly, in an air conditioning system that controls the room temperature based on the surface temperature of the object in the room, it is desired to accurately identify the surface temperature of the non-heating object in the room in the above-mentioned equilibrium state by the temperature measuring device. Therefore, it is important for the temperature measuring device for air conditioning to accurately measure the surface temperature of the non-heating object in the above-mentioned equilibrium state, that is, the measurement target temperature Tt.

[0010] Considering the above-mentioned premise, in the conventional temperature measuring device, when the circuit board is not generating heat, the temperature of the sensor device or the reference junction, i.e., the reference temperature Tc, is close to room temperature, and there is no problem with the measurement accuracy of the measurement target temperature Tt, which is the surface temperature of the non-heating body. On the other hand, when the circuit board generates heat, the heat generated by the circuit board is trapped inside the housing, the sensor device warms up, and as a result, the reference temperature Tc rises and moves away from room temperature. For this reason, when the circuit board generates heat, the measurement accuracy of the surface temperature of the non-heating body in the above-mentioned equilibrium state decreases, and the derived measurement target temperature Tt differs from the actual measurement target temperature Tt.

[0011] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to accurately measure the surface temperature of a non-heat-generating object in a room. [Means for solving the problem]

[0012] In order to solve the above problems, the temperature measuring device of the present invention is a temperature measuring device for air conditioning that measures the surface temperature of a measurement object inside a room, and comprises a sensor device comprising a temperature difference sensor having a reference junction and a hot junction that is heated by infrared rays from the measurement object and converting the temperature difference between the reference junction and the hot junction into an electromotive force, and a contact-type temperature sensor that detects the temperature of the reference junction, a circuit board that derives the surface temperature of the measurement object based on the electromotive force converted by the temperature difference sensor and the temperature of the reference junction detected by the temperature sensor, a fan that generates wind to move heat generated by the circuit board away from the sensor device, and a housing that houses the sensor device, the circuit board, and the fan, and is provided with an exhaust port through which the wind from the fan passes.

[0013] The housing may include an air intake port that takes in air from outside the housing when the wind is generated by the fan.

[0014] The sensor device may further include a heat insulating member provided between the sensor device and the circuit board inside the housing, for insulating the sensor device from heat generated by the circuit board.

[0015] The insulating member may separate a first space within the housing in which the sensor device is located from a second space in which the circuit board is located, and the housing may have an opening that connects the interior of the room to the space around the sensor device in the first space.

[0016] The circuit board may be configured to control the fan to reduce the volume of the air when it detects that the electromotive force or the derived surface temperature of the object is higher than a predetermined reference value.

[0017] The sensor device may include a plurality of the temperature difference sensors, and the circuit board may derive a surface temperature of each of the measurement objects of the plurality of temperature difference sensors based on the electromotive forces converted by each of the plurality of temperature difference sensors and the temperature of the reference junction detected by the temperature sensor. Effect of the Invention

[0018] According to the present invention, the surface temperature of a non-heat-generating object in a room can be measured with high accuracy. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram illustrating a schematic structure of a temperature measuring device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing the configuration of the temperature difference sensor shown in FIG. [Diagram 3] FIG. 3 is a diagram showing a schematic structure of a temperature measuring device according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing a schematic structure of a temperature measuring device according to a modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] [First embodiment] A temperature measuring device 10 according to a first embodiment of the present invention will be described with reference to Fig. 1 and Fig. 2. As shown in Fig. 1, the temperature measuring device 10 is installed on a ceiling 91 of a room 90. The temperature measuring device 10 is configured for air conditioning that controls the room temperature of the room 90, and is configured to be able to communicate with an air conditioning system S that controls the room temperature. The temperature measuring device 10 in Fig. 1 is drawn large and is actually much smaller.

[0021] The temperature measuring device 10 measures the surface temperature of a plurality of objects present within its own measurement range W, that is, a floor 95A, a desk 95B, and a group of people 95C, as measurement objects 95 for each divided range Wn in the example of FIG. 1. In other words, the temperature measuring device 10 measures the surface temperature of each of the measurement objects 95n, with each portion of the measurement object 95 divided by the divided range Wn being a measurement object 95n. The surface temperature is measured based on infrared rays emitted from the measurement object 95n. The measurement objects 95 and 95n may include walls, computers, etc., depending on the layout or state of the room 90. The objects in the room 90 include structures such as floors, walls, ceilings, and columns that constitute the room 90. In the example of FIG. 1, the number of divided ranges Wn is four, but the actual number of divided ranges Wn is greater than that. The divided ranges Wn and the measurement targets 95n are arranged in a matrix, for example, 16×16, when viewed from the top-bottom direction.

[0022] The temperature measuring device 10 includes a housing 20, a sensor device 30, a circuit board 40, a signal transmission unit 50, and a fan 60. Note that hatched portions in Fig. 1 indicate cross sections (the same applies to other figures such as Fig. 3).

[0023] The housing 20 accommodates each of the components 30 to 60 such as the sensor device 30 in its internal space R, and is attached to the ceiling 91 with a part of the housing 20 inserted into a through hole 91A opened in the ceiling 91. The housing 20 may be attached to the ceiling 91 in any manner. For example, the housing 20 is fixed by being hooked to the ceiling 91 by a pair of leaf springs attached to the housing 20. The housing 20 may be attached to the ceiling 91 by bolts or the like. The housing 20 includes a bottom plate 21 having a shape such as a circle, and a cup-shaped member 22 having a polygonal tube or cylinder shape with a closed upper end and a lower end attached to the bottom plate 21, which covers the above-mentioned components 30 to 60. The bottom plate 21 closes the through hole 91A in the ceiling 91. The cup-shaped member 22 enters the ceiling space 95. A through hole 21A is formed in the center of the bottom plate 21 to expose the lower part of the sensor device 30 to the room 90 side. The bottom plate 21 is provided with an air intake port H1 for introducing air within the room 90 into the housing 20. The upper part of the cup-shaped member 22 is provided with an exhaust port H2 for exhausting the air within the housing 20 to the ceiling space 95.

[0024] The sensor device 30 performs infrared sensing and the like to measure the surface temperature of a measurement target 95n. The sensor device 30 includes a housing 31, an optical system 32, a sensor chip 33, and a temperature sensor 34. In Fig. 1, each of the elements 31 to 34 of the sensor device 30 is illustrated diagrammatically.

[0025] The housing 31 houses the optical system 32, the sensor chip 33, and the temperature sensor 34. The housing 31 has a through-hole 31A in its lower part, i.e., the part exposed from the housing 20, through which infrared rays emitted from the measurement target 95 pass. The optical system 32 includes a lens and the like that receives the infrared rays that pass through the through-hole 31A of the housing 31 and focuses the light on the sensor chip 33.

[0026] The sensor chip 33 includes a plurality of temperature difference sensors 33n arranged in a matrix corresponding to the plurality of measurement objects 95n, respectively. As shown in Fig. 2, each temperature difference sensor 33n includes a reference junction D1 and a hot junction D2 that is heated by infrared rays from the measurement object 95n collected by the optical system 32, and converts the temperature difference between the reference junction D1 and the hot junction D2 into an electromotive force V.

[0027] The temperature difference sensor 33n includes a sensing element M consisting of two kinds of metal wires M1 and M2 (thermocouples) connected alternately. The metal wires M1 and M2 are made of different materials. The reference junction D1 includes a set of every other connection point C among the multiple connection points C of the two kinds of metal wires M1 and M2. The hot junction D2 includes a set of the remaining connection points C among the multiple connection points C. Furthermore, the hot junction D2 includes a heat generating layer L that absorbs infrared light collected by the optical system 32 and generates heat. The heat generating layer L generates heat, thereby warming the connection points C of the hot junction D2. The heat generating layer L may be a layer that absorbs light of a wide range of wavelengths including infrared light and generates heat. In this case, the optical system 32 may be provided with a filter that transmits infrared light and absorbs other light, and the sensor device 30 may be configured so that only infrared light reaches the heat generating layer L among the light that passes through the through hole of the housing 31.

[0028] As the hot junction D2 is heated, a temperature difference occurs between the reference junction D1 and the hot junction D2. This temperature difference generates an electromotive force (potential difference) V across the two ends of the sensing element M, which is made up of metal wires M1 and M2 connected in series (Seebeck effect). In this manner, the temperature difference sensor 33n is configured to convert the temperature difference between the reference junction D1 and the hot junction D2 into an electromotive force V. The temperature difference sensor 33n outputs the electromotive force V obtained by the conversion to the circuit board 40 in the form of an electrical signal. The temperature difference sensor 33n may be configured from a single thermocouple.

[0029] The temperature sensor 34 is a contact-type temperature measuring element such as a thermistor. The temperature sensor 34 comes into contact with a predetermined portion of the sensor chip 33 and detects the temperature of the predetermined portion. This predetermined portion is a portion having the same temperature as the temperature of the reference junction D1. The temperature sensor 34 detects the temperature of the predetermined portion to detect a reference temperature Tc, which is the temperature of the reference junction D1. The temperature sensor 34 detects and outputs the reference temperature Tc by converting the reference temperature Tc of the reference junction D1 into a resistance value or the like and outputting an electrical signal indicating the converted resistance value or the like.

[0030] The sensor device 30 receives infrared rays from the measurement target 95n, and is therefore provided in a position near the room 90. In this embodiment, in particular, the sensor device 30 is exposed from the housing 20 towards the room 90, and is in contact with the space within the room 90. As a result, the sensor device 30 (in particular, the reference junction D1) is affected by room temperature, and specifically, when the temperature of the sensor device 30 is different from room temperature, it is heated or cooled by the room temperature, and has a temperature approximately equal to the room temperature within the room 90.

[0031] The circuit board 40 includes a board, wiring and various electronic elements mounted on the board, and executes a process for measuring the temperature of each measurement target 95n. The electronic elements of the circuit board 40 include a processor such as a CPU (Central Processing Unit), a memory, a resistor, and a capacitor. Such a circuit board 40 may generate heat during its operation. The circuit board 40 is disposed above the sensor device 30, that is, at a position farther from the room 30 than the sensor device 30.

[0032] The circuit board 40 acquires, in the form of an electric signal, the electromotive force V into which each temperature difference sensor 33n of the sensor chip 33 converts the temperature difference, via a signal transmission unit 50 having a plurality of signal lines for transmitting signals exchanged between the sensor device 30 and the circuit board 40. The circuit board 40 may control a field effect transistor (FET) for selecting the temperature difference sensor 33n provided on the sensor chip 33 to sequentially select each temperature difference sensor 33n, and sequentially acquire the electromotive force V from each of the sequentially selected temperature difference sensors 33n. The circuit board 40 may be individually connected to each temperature difference sensor 33n via the signal transmission unit 50, and acquire the electromotive force V individually from each temperature difference sensor 33n. The circuit board 40 also acquires, in the form of an electric signal, the reference temperature Tc detected by the temperature sensor 34 via the signal transmission unit 50.

[0033] The circuit board 40 performs analog-to-digital conversion on the electromotive force V and the reference temperature Tc acquired above, and calculates the converted electromotive force V and the reference temperature Tc according to the above formula (2) (Tt= 4 √(V / α+Tc 4)) and derives the measurement object temperature Tt, which is the surface temperature of the measurement object 95n. The circuit board 40 derives the measurement object temperature Tt by substituting the converted electromotive force V and the reference temperature Tc into, for example, equation (2) previously prepared in memory, or by referring to a table representing the relationship of equation (2) previously prepared in memory based on the converted electromotive force V and the reference temperature Tc. The circuit board 40 derives the measurement object temperature Tt for each temperature difference sensor 33n. The coefficient α of equation (2) may take different values ​​depending on the value of the electromotive force V, etc. Therefore, the circuit board 40 obtains the actual value of the coefficient α using a function previously prepared in memory, or by referring to a table previously prepared in memory.

[0034] The circuit board 40 generates a thermal image showing the temperature distribution for each measurement target 95n based on the measurement target temperature Tt derived for each temperature difference sensor 33n, and outputs the generated thermal image wirelessly or via cable to the air conditioning system S. The air conditioning system S controls the room temperature of the room 90 based on the thermal image, i.e., the surface temperature of the measurement target measured by the temperature measuring device 10.

[0035] The fan 60 is disposed above the circuit board 40 and operates under the control of the circuit board 40 to send wind F upward. The exhaust port H2 of the housing 20 is disposed above the fan 60 and in a position facing the fan 60 of the housing 20, and the wind F passes through the exhaust port H2. When the wind F is generated, the air in the room 90 (internal space R) outside the housing 20 is taken into the housing 20 by the intake port H1 of the housing 20. The wind F enters the internal space R of the housing 20 from the room 90 through the intake port H1, passes through the internal space R of the housing 20, and flows out of the housing 20 from the exhaust port H2. The heat generated by the circuit board 40 is carried by the wind F and discharged to the ceiling 95 through the exhaust port H2. Therefore, the heat generated by the circuit board 40 is not transmitted or is difficult to transmit to the sensor device 30.

[0036] The fan 60 operates at any timing under the control of the circuit board 40. For example, the circuit board 40 may operate the fan 60 when the number of processes it executes is large and it is highly likely that it is generating heat. A temperature sensor may be provided on the circuit board 40, and the circuit board 40 may operate the fan 60 when its own temperature is detected by the temperature sensor to be higher than a predetermined threshold. Furthermore, the circuit board 40 may increase the number of rotations of the fan 60 as its own temperature increases (including a mode in which the number of rotations of the fan 60 is increased stepwise depending on the range of its own temperature). Thus, the power consumption of the fan 60 can be reduced. The fan 60 may be controlled to operate at a constant speed all the time in order to reduce the processing load on the circuit board 40 and reduce heat generation.

[0037] Here, the effect of this embodiment will be described. As described above, if the reference temperature Tc, which is the temperature of the reference junction D1, is brought close to the measurement target temperature Tc to reduce the electromotive force V, the effect of the coefficient α on the measurement target temperature Tt is reduced. As a result, the measurement accuracy of the measurement target temperature Tt is improved when the measurement target 95n is a non-heat-generating body having a surface temperature that is in equilibrium with room temperature. However, in the past, the heat generated by the circuit board 40 warms the reference junction D1 of the sensor device 30, which is affected by the room temperature in the room 90 and has a temperature equivalent to room temperature, thereby reducing the measurement accuracy. In this embodiment, a fan 60 is provided that generates wind F to move the heat generated by the circuit board 40 away from the sensor device 30, and the wind F exhausts the heat of the circuit board 40 from the exhaust port H2 to the outside of the housing 20, so that the heat generated by the circuit board 40 is prevented from being transmitted to the sensor device 30 or is difficult to be transmitted. Therefore, the reference junction D1 of the sensor device 30 is less likely to heat up, the reference temperature Tc is maintained close to room temperature, and the measurement target temperature Tt of the non-heat-generating body, that is, the surface temperature of the non-heat-generating body, is measured with high accuracy.

[0038] Furthermore, the temperature measuring device 10 in this embodiment can simultaneously measure the surface temperatures of various kinds of objects in the room 90, such as the floor 95A, the desk 95B, and the person 95C, by using the multiple temperature difference sensors 33n. Generally, non-heat-generating objects such as the floor 95A and the desk 95B occupy most of the room 90, and heat-generating objects such as the person 95C occupy only a small area of ​​the room 90. Therefore, in this embodiment, the surface temperatures of most of the room 90 are measured with high accuracy. In addition, in the air conditioning of the room 90, the air conditioner of the air system may be controlled according to the average temperature of the measurement object temperatures Tt of all the measurement objects 95n. Since the proportion of non-heat-generating objects in all the measurement objects 95n is large, the average temperature with high accuracy can be obtained according to this embodiment.

[0039] Incidentally, since the sensor device 30 measures the surface temperature of the measurement target 95n based on the reference temperature Tc, which is its own temperature, it was previously thought that there would be no problem with the measurement accuracy of the surface temperature (temperature of the measurement target Tt) even if the sensor device 30 was heated. In other words, there was no need to provide the fan 60. As described above, this embodiment focuses on the fact that heating the sensor device 30 by the circuit board 40 reduces the measurement accuracy of the surface temperature of a non-heat-generating body that is often the measurement target in temperature measurement for air conditioning, and therefore the fan 60 is deliberately adopted.

[0040] Furthermore, in addition to the infrared rays radiated from the measurement object 95n, infrared rays reflected by the measurement object 95n are also incident on the sensor device 30. The reflected infrared rays are due to the radiant energy of the room temperature (ceiling 91, walls, etc.). By bringing the reference temperature Tc of the sensor device 30 closer to the room temperature of the room 90, the reflected infrared rays can be cancelled when measuring the measurement object temperature Tt, improving the accuracy of the temperature measurement.

[0041] [Second embodiment] Next, a temperature measuring device 110 according to a second embodiment will be described with reference to Fig. 3. In the following, the differences from the first embodiment will be mainly described, and the same or similar members as those in the first embodiment will be denoted by the same reference numerals and descriptions thereof will be omitted as appropriate.

[0042] As shown in FIG. 3, the temperature measuring device 110 further includes a heat insulating member 170 . The heat insulating member 170 is provided between the sensor device 30 and the circuit board 40, and insulates the sensor device 30 from heat generated by the circuit board 40. The heat insulating member 170 has a heat insulating layer 171 such as an air layer or a vacuum layer inside. The heat insulating member 170 may be formed of an appropriate heat insulating material such as glass wool or urethane foam. Each signal line of the signal transmission unit 50 connected to the sensor device 30 and the circuit board 40 passes through the heat insulating member 170. The heat insulating member 170 is formed in a cylindrical or polygonal tubular shape with a closed top that covers the sensor device 30 from above, that is, in a cup shape. The cup-shaped heat insulating member 170 is provided in the internal space R of the housing 20, and separates the space R1 in which the sensor device 30 is located from the space R2 in which the circuit board 40 is located. As a result, the space R1 and the space R2 of the internal space R are separated by the heat insulating member 170, and the heat generated by the circuit board 40 is not or is difficult to transmit through the sensor device 30. The heat insulating member 170 may cover the sensor device 30 in a shape that contacts the sensor device 30. In this case, the space R1 does not include the space around the sensor device 30.

[0043] 3, an opening 21D that communicates the inside of the room 90 with the space R1 may be provided in a portion 21C (here, a portion inside the cup-shaped member 22 of the bottom plate 21) that partitions the space R1 out of the internal space R of the housing 20 of the temperature measuring device 110 and is adjacent to the inside of the room 90. The opening 21D allows air in the room 90 to be introduced into the space R1 in which the sensor device 30 is located, and this allows the temperature of the sensor device 30 or the reference junction D1 to be closer to the room temperature of the room 90. Note that the number of openings 21D is arbitrary, but it is preferable to provide a plurality of openings 21D so that air can easily flow in and out between the inside of the room 90 and the space R1.

[0044] 4, the heat insulating member 170 may be formed in a plate shape that divides the internal space R into a space R1 where the sensor device 30 is located and a space R2 where the circuit board 40 is located, and separates the space R1 from the space R2. In such a case, the air intake port H1 is formed in a portion of the cup-shaped member 22 of the housing 20 that divides the space R2. The air intake port H1 is preferably disposed at a position where the circuit board 40 is located between the air intake port H1 and the air exhaust port H2. This allows the wind F to effectively exhaust the heat of the circuit board 40 to the outside of the housing 20.

[0045] The heat insulating member 170 can also prevent the temperature of the sensor device 30 from dropping due to the wind F hitting the sensor device 30. When no heat insulating member is provided, it is desirable that the air intake H1 be located at a position where the wind F does not hit the sensor device 30.

[0046] [Variations] The above-described embodiments may be modified. For example, the shape and number of each component of the temperature measuring devices 10 and 110 (hereinafter, also referred to as the temperature measuring device 10, etc.) may be arbitrary.

[0047] [Variation 1] The circuit board 40 may control the rotation speed of the fan 60 (air pressure of the wind F) according to the surface temperature of the measurement target 95n. If the measurement target 95n is, for example, a floor 95A with a floor heating function, the floor 95A becomes higher than the room temperature of the room 90 when the floor heating is in operation. In this case, if the reference temperature Tc is close to the room temperature, the electromotive force V becomes large, and the measurement error of the measurement target temperature Tt becomes large. Therefore, the circuit board 40 may reduce the rotation speed of the fan 60 and reduce the air volume of the wind F when it detects that the electromotive force V or the derived measurement target temperature Tt of the measurement target 95n is higher than a predetermined reference. Reducing the rotation speed includes setting the rotation speed to 0, that is, stopping the operation of the fan 60. By reducing the rotation speed of the fan 60, heat generated by the circuit board 40 is transmitted to the sensor device 30, and the temperature of the reference temperature Tc increases, approaching the surface temperature (measurement target temperature Tt) of the floor 95A that is heated by the floor heating. Therefore, the electromotive force V becomes smaller.

[0048] For example, the circuit board 40 may determine whether the measurement target temperature Tt (for the temperature range, the average value, etc.) of the largest area among areas in the thermal image where the measurement target temperatures Tt are collected, which have the same temperature or are within the same temperature range, exceeds a predetermined threshold. When the circuit board 40 determines that the measurement target temperature Tt has exceeded the predetermined threshold, it may detect that the measurement target temperature Tt derived as described above is higher than a predetermined reference, and may reduce the rotation speed of the fan 60 (for example, stop the fan 60). In addition, when the circuit board 40 detects that the floor heating or the like is switched on, for example, when it receives a signal indicating the on from the outside, it may detect that the measurement target temperature Tt is higher than a predetermined reference (including that it will become higher in the future), and may reduce the rotation speed of the fan 60. The circuit board 40 may increase the rotation speed of the fan 60 as the derived measurement target temperature Tt becomes higher (including an aspect in which the rotation speed is increased stepwise depending on which range the measurement target temperature Tt belongs to). The circuit board 40 may control the fan 60 based on the electromotive force V instead of the temperature to be measured Tt (in this case, the temperature to be measured Tt in the above description is replaced with the electromotive force V).

[0049] In this embodiment, when the measurement object 95n is a heating element or the like and the measurement object temperature Tt is different from room temperature, the heat generated by the circuit board 40 is transferred to the sensor device 30 to bring the reference temperature Tc and the measurement object temperature Tt closer together, thereby enabling the surface temperature of the measurement object (heating element) to be measured with high accuracy.

[0050] [Variation 2] The relationship used by the circuit board 40 when deriving the measurement target temperature Tt based on the electromotive force V and the reference temperature Tc is not limited to the above formula (1) and formula (2). For example, the relationship may be substantially the above formula (1) and formula (2), and the fourth power and the fourth root of the above formula (1) and formula (2) may be the 3.9th power and the 3.9th root. Other formulas may also be used. As long as the measurement target temperature Tt is derived based on the electromotive force V and the reference temperature Tc, the derivation accuracy of the measurement target temperature Tt does not exceed the measurement accuracy of the reference temperature Tc on which it is based, as in the case described above. When the measurement target temperature Tt is derived from the electromotive force V, the larger the electromotive force V, the larger the measurement error of the measurement target temperature Tt. Therefore, even when the measurement target temperature Tt is derived based on a formula other than the above formula (1) and formula (2), the above effect of the fan 60 and the like can be obtained.

[0051] [Variation 3] The temperature measuring device 10 etc. may be installed at any location within the room 90 (inside the room). The any location may include structures such as the ceiling 91 that constitutes the room 90, as well as walls, floors, and pillars. The temperature measuring device 10 etc. may be installed by being embedded in any structure, as in the above embodiment. The temperature measuring device 10 may be installed in any direction. The top and bottom in the above embodiment may be such that the side to be measured is bottom and the opposite side is top. Furthermore, the sensor device 30 such as the temperature measuring device 10 may have one temperature difference sensor 33n instead of multiple ones.

[0052] [Scope of the present invention] Although the present invention has been described above with reference to the embodiment and the modified examples, the present invention is not limited to the above embodiment and the modified examples. For example, the present invention includes various modifications to the above embodiment and the modified examples that can be understood by a person skilled in the art within the scope of the technical idea of ​​the present invention. The configurations listed in the above embodiment and the modified examples can be appropriately combined within a range without contradiction. [Explanation of symbols]

[0053] 10,110,210...temperature measuring device, 20...housing, H1...air intake, H2...air exhaust, 2D...opening, 30...sensor device, 33...sensor chip, 33n...temperature difference sensor, 34...temperature sensor, 40...circuit board, 170...insulating member, 95,95n...measurement object, 95A...floor, 95B...desk, 95C...person, R...internal space, R1,R2...space.

Claims

1. A temperature measuring device for air conditioning that measures the surface temperature of a measurement object in a room, a temperature difference sensor having a reference junction and a hot junction that is heated by infrared rays from the object to be measured and converting a temperature difference between the reference junction and the hot junction into an electromotive force, and a contact-type temperature sensor that detects the temperature of the reference junction; a circuit board that derives a surface temperature of the measurement object based on the electromotive force converted by the temperature difference sensor and the temperature of the reference junction detected by the temperature sensor; a fan that generates airflow to move heat generated by the circuit board away from the sensor device; a housing that houses the sensor device, the circuit board, and the fan, the housing having an exhaust port through which the wind generated by the fan passes; a heat insulating member provided between the sensor device and the circuit board in the housing to insulate the sensor device from heat generated by the circuit board, the heat insulating member separates a first space in the housing in which the sensor device is located and a second space in which the circuit board is located, The housing has an opening that communicates the room with a space around the sensor device in the first space. Temperature measuring device.

2. The housing has an air intake port that takes in air from outside the housing when the wind is generated by the fan. The temperature measuring device of claim 1 .

3. When the circuit board detects that the electromotive force or the derived surface temperature of the measurement target is higher than a predetermined reference value, the circuit board controls the fan to reduce the air volume of the air.

3. The temperature measuring device according to claim 1 or 2.

4. The sensor device includes a plurality of the temperature difference sensors, the circuit board derives a surface temperature of each of the measurement targets of the plurality of temperature difference sensors based on the electromotive forces converted by each of the plurality of temperature difference sensors and the temperatures of the reference junctions detected by the temperature sensors. A temperature measuring device according to any one of claims 1 to 3.

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