Temperature measuring device

Abstract

A temperature measuring device (10) for an air conditioner measures the surface temperature of a non-heat-generating body in a room with high accuracy. The device comprises a housing (20), a sensor device (30), a circuit substrate (40), and a heat insulating member (60). The housing accommodates the sensor device, the circuit substrate, and the heat insulating member. The sensor device comprises a temperature difference sensor (33n) and a contact temperature sensor (34). The temperature difference sensor comprises a reference junction and a hot junction heated by infrared rays from an object in a room (90), i.e., a measurement object (95a), and converts the temperature difference between the reference junction and the hot junction into an electromotive force. The contact temperature sensor detects the temperature of the reference junction. The circuit substrate derives the surface temperature of the measurement object (95n) based on the electromotive force converted by the temperature difference sensor and the temperature of the reference junction detected by the temperature sensor. The heat insulating member is provided between the sensor device and the circuit substrate to insulate the sensor device from heat emitted from the circuit substrate.

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 in a room. Background Art

[0002] Patent Document 1 discloses a temperature measuring device for air conditioning. This device is installed in a room and uses infrared radiation from objects within the room, such as walls, floors, tables, personal computers, and people, to measure their surface temperatures. The measured surface temperatures are transmitted to the air conditioning system and used for indoor room control.

[0003] A conventional temperature measuring device for an air conditioner consists of a sensor device, a circuit board, and a housing housing these components. The sensor device includes a reference junction and a hot junction heated by infrared radiation from the object being measured. It is equipped with a temperature difference sensor that converts the temperature difference between the two junctions into an electromotive force V. The sensor device also includes a contact-type temperature sensor that detects the temperature of the reference junction, or reference temperature Tc. The circuit board derives the object temperature Tt, which is the surface temperature of the object being 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 as shown in the following formula (1): Here, α is a coefficient, which is obtained in advance through experiments or the like.

[0005] V=α(Tt 4 -Tc 4 )…(1)

[0006] The circuit board of the temperature measuring device derives the measurement target temperature Tt based on the reference temperature Tc and the electromotive force V by the following equation (2) which is a modification of the above equation (1).

[0007]

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-56546 Summary of the Invention

[0011] Problems to be solved by the invention

[0012] The inventors of the present application have conducted various studies on the above-mentioned temperature measuring device and, as a result, have discovered the following problems and have completed the present invention.

[0013] First, referring to the above formulas (1) and (2), when the electromotive force V = 0, that is, when the reference temperature Tc is equal to the measurement object temperature Tt, the coefficient α has no effect on the derivation of the measurement object temperature Tt. On the contrary, the larger the absolute value of the electromotive force V, the greater the influence of α on the derived measurement object temperature Tt. Here, the reference temperature Tc is detected by a contact type temperature sensor and is therefore detected with relatively high accuracy. On the other hand, the coefficient α is obtained based on experimental results, etc., but it is difficult to express it correctly because it is affected by various factors. That is, the coefficient α will produce an error in any case. Therefore, if the reference temperature Tc is brought close to the measurement object temperature Tt and the electromotive force V is reduced, the influence of the coefficient α on the measurement object temperature Tt becomes smaller, and as a result, the measurement accuracy of the measurement object temperature Tt is improved.

[0014] Here, the measurement object of the temperature measuring device for air conditioning is an indoor object as described above, including non-heat-generating objects such as floors, tables, or walls. When the surface temperature of the non-heat-generating object and the room temperature in the room are in equilibrium, the two are approximately the same temperature. Therefore, when the reference temperature Tc is close to the room temperature, the reference temperature Tc is close to the surface temperature of the non-heat-generating object as the measurement object, that is, the measurement object temperature Tt. Therefore, in this case, the measurement accuracy of the measurement object temperature Tt is good. Here, most of the objects in the room are non-heat-generating objects such as floors, walls, tables, and bookshelves. In addition, compared with when the room temperature changes rapidly, the people in the room are more sensitive to changes in the room temperature in the equilibrium state. Therefore, in an air conditioning system that controls the room temperature based on the surface temperature of the indoor objects, it is desired to use a temperature measuring device to determine the surface temperature of the non-heat-generating object in the equilibrium state with high accuracy. Therefore, it is important for the temperature measuring device for air conditioning to measure the surface temperature of the non-heat-generating object in the equilibrium state as described above, that is, the measurement object temperature Tt with high accuracy.

[0015] Based on the above situation, an examination of existing temperature measuring devices reveals that, when the circuit substrate is not heating, the temperature of the sensor device or reference junction, i.e., the reference temperature Tc, is close to room temperature, and the accuracy of measuring the surface temperature of the non-heating element, i.e., the measurement target temperature Tt, does not pose a problem. On the other hand, when the circuit substrate is heating, the heat generated by the circuit substrate is retained within the housing, causing the sensor device to heat up, resulting in the reference temperature Tc rising and moving away from room temperature. Therefore, when the circuit substrate is heating, the accuracy of measuring the surface temperature of the non-heating element in the equilibrium state described above is reduced, and the derived measurement target temperature Tt differs from the actual measurement target temperature Tt.

[0016] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to measure the surface temperature of a non-heat-generating object in a room with high accuracy.

[0017] Technical means to solve the problem

[0018] In order to solve the above-mentioned 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 in a room, and the temperature measuring device comprises: a sensor device, which has a temperature difference sensor and a contact temperature sensor, the temperature difference sensor has a reference junction and a hot junction heated by infrared rays from the measurement object, and converts the temperature difference between the reference junction and the hot junction into an electromotive force, and the contact temperature sensor detects the temperature of the reference junction; a circuit substrate, which 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 frame, which accommodates the sensor device and the circuit substrate; and a heat insulating member, which is arranged in the frame and between the sensor device and the circuit substrate, so as to thermally insulate the sensor device from heat emitted from the circuit substrate.

[0019] The heat insulating member may separate a first space in the housing where the sensor device is located from a second space in which the circuit board is located, and the housing may include a first opening communicating between the interior of the chamber and the space surrounding the sensor device in the first space.

[0020] The housing may include a second opening for communicating the outside of the room with the space surrounding the circuit board in the second space.

[0021] The heat insulating member may also be configured to include a through hole connecting the first space and the second space and a door for opening and closing the through hole, wherein when the door is opened and at least a portion of the through hole is opened, the heat generated by the circuit substrate is transferred to the sensor device via the through hole.

[0022] A drive device for driving the door may be further provided, and when the circuit board detects that the electromotive force or the derived surface temperature of the measurement object is higher than a predetermined reference, the circuit board controls the drive device to open the door.

[0023] The sensor device may also include a plurality of the temperature difference sensors, and the circuit board may derive the surface temperature of each of the measurement objects of the plurality of temperature difference sensors based on the respective electromotive forces converted by the plurality of temperature difference sensors and the temperature of the reference junction detected by the temperature sensor.

[0024] Effects of the Invention

[0025] 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

[0026] Figure 1 This is a diagram schematically showing the structure of a temperature measuring device according to a first embodiment of the present invention.

[0027] Figure 2 Yes Figure 1 Diagram of the composition of the temperature difference sensor.

[0028] Figure 3 This is a diagram schematically showing the structure of a temperature measuring device according to a second embodiment of the present invention.

[0029] Figure 4 This is a diagram schematically showing the structure of a temperature measuring device according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0030] [First embodiment]

[0031] Reference Figure 1 as well as Figure 2 A temperature measuring device 10 according to a first embodiment of the present invention will be described. Figure 1 As shown, the temperature measuring device 10 is installed on the ceiling 91 of the room 90. The temperature measuring device 10 is configured for air conditioning to control the room temperature of the room 90 and is configured to be communicable with the air conditioning system S that controls the room temperature. Figure 1 The temperature measuring device 10 is exaggeratedly enlarged and is actually smaller.

[0032] The temperature measuring device 10 measures the temperature of the room 90, that is, the temperature of the room 90, which is within the measurement range W of the device. Figure 1 In the example, the floor 95A, the table 95B, and the person 95C are taken as the measurement object 95, and the surface temperature thereof is measured for each segmented range Wn. In other words, the temperature measuring device 10 divides the measurement object 95 into each portion obtained by dividing the segmented range Wn as the measurement object 95n, and measures the surface temperature of each measurement object 95n. The measurement of the surface temperature is based on the infrared rays emitted from the measurement object 95n. The measurement objects 95 and 95n may include walls or personal computers, etc., depending on the layout or status of the room 90. Objects in the room 90 include structures such as the floor, walls, ceiling, and pillars that constitute the room 90. In Figure 1 In the example shown in FIG, the number of divided ranges Wn is 4, but the actual number of divided ranges Wn is larger than this. When viewed from the top and bottom, the divided ranges Wn and the measurement objects 95n are arranged in a matrix, for example, 16×16.

[0033] The temperature measuring device 10 includes a housing 20, a sensor device 30, a circuit board 40, a signal transmission unit 50, and a heat insulating member 60. Figure 1 The hatched part represents the cross section (in Figure 3 The same applies to other figures).

[0034] The housing 20 houses the sensor device 30 and other components 30 to 60 within its internal space R. The housing 20 is mounted on the ceiling 91 with a portion of the housing inserted into a through-hole 91A provided in the ceiling 91. The mounting method of the housing 20 on the ceiling 91 is arbitrary. For example, the housing 20 can be suspended from the ceiling 91 by a pair of leaf springs attached to the housing 20 and secured thereto. Alternatively, the housing 20 can be mounted on the ceiling 91 using bolts or the like. The housing 20 comprises a bottom plate 21 having a circular or other shape, and a cup-shaped member 22, which has a polygonal or cylindrical shape, attached to the bottom plate 21 at its lower end and a closed upper end, and covers the components 30 to 60. The bottom plate 21 blocks the through-hole 91A in the ceiling 91. The cup-shaped member 22 extends into the back surface 95 of the ceiling. A through-hole 21A is formed in the center of the bottom plate 21, exposing the lower portion of the sensor device 30 to the room 90.

[0035] The sensor device 30 performs infrared sensing for measuring the surface temperature of the measurement object 95n. The sensor device 30 includes a housing 31, an optical system 32, a sensor chip 33, and a temperature sensor 34. Figure 1 , the individual elements 31 - 34 of the sensor device 30 are schematically shown.

[0036] 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 at its lower portion, i.e., the portion exposed from the housing 20, through which infrared light emitted from the measurement object 95 passes. The optical system 32 includes a lens, etc., which receives the infrared light passing through the through-hole 31A of the housing 31 and focuses it on the sensor chip 33.

[0037] The sensor chip 33 includes a plurality of temperature difference sensors 33n corresponding to the plurality of measurement objects 95n and arranged in a matrix. Figure 2 As shown, one temperature difference sensor 33n includes a reference junction D1 and a hot junction D2 heated by infrared rays from the measurement object 95n focused 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.

[0038] The temperature difference sensor 33n has a sensing element M composed of two metal wires M1 and M2 (thermocouples) connected alternately. The metal wires M1 and the metal wires M2 are formed of different materials. The reference junction D1 includes a set of connection points C that jump out of a plurality of connection points C of the two metal wires M1 and M2. The hot junction D2 includes a set of the remaining connection points of the plurality of connection points C. In addition, the hot junction D2 has a heating layer L that absorbs infrared rays focused by the optical system 32 and generates heat. The connection point C of the hot junction D2 is heated by the heat generated by the heating layer L. The heating layer L can be a layer that absorbs light of a wide range of wavelengths including infrared rays and generates heat. In this case, a filter that transmits infrared rays and absorbs other light is provided on the optical system 32, and the sensor device 30 is constructed in such a way that only infrared rays in the light that has passed through the through hole of the frame 31 reach the heating layer L.

[0039] As hot junction D2 is heated, a temperature difference is generated between reference junction D1 and hot junction D2. This temperature difference generates an electromotive force (potential difference) V across sensor element M, which is composed of series-connected metal wires M1 and M2 (Seebeck effect). Thus, temperature difference sensor 33n is configured to convert the temperature difference between reference junction D1 and hot junction D2 into electromotive force V. Temperature difference sensor 33n outputs the converted electromotive force V as an electrical signal to circuit board 40. Temperature difference sensor 33n can be configured as a single thermocouple.

[0040] Temperature sensor 34 is a contact-type temperature measuring element, such as a thermistor. Temperature sensor 34 contacts a predetermined portion of sensor chip 33 and detects the temperature of that predetermined portion. This predetermined portion has the same temperature as reference junction D1. By detecting the temperature of this predetermined portion, temperature sensor 34 detects the temperature of reference junction D1, i.e., reference temperature Tc. Temperature sensor 34 converts reference temperature Tc at reference junction D1 into a resistance value, etc., and outputs an electrical signal representing the converted resistance value, etc., thereby detecting and outputting reference temperature Tc.

[0041] The sensor device 30 receives infrared rays from the measurement object 95n and is therefore installed near the room 90. In this embodiment, the sensor device 30 is exposed from the housing 20 toward the room 90 side and is in contact with the space within the room 90. Therefore, the sensor device 30 (particularly the reference junction D1) is affected by the room temperature. Specifically, when the temperature of the sensor device 30 differs from the room temperature, it is heated or cooled by the room temperature and has a temperature approximately equal to that of the room temperature within the room 90.

[0042] The circuit board 40 includes a substrate, wiring mounted on it, and various electronic components. It performs processing to measure the temperature of each measurement object 95n. Electronic components of the circuit board 40 include a processor such as a CPU (Central Processing Unit), memory, resistors, and capacitors. This circuit board 40 may generate heat during operation. The circuit board 40 is located above the sensor device 30, that is, farther away from the room 30 than the sensor device 30.

[0043] The circuit board 40 acquires the electromotive force V, obtained by converting the temperature difference into an electromotive force, from each temperature difference sensor 33n on the sensor chip 33, via a signal transmission unit 50 having multiple signal lines for transmitting signals between the sensor device 30 and the circuit board 40. Alternatively, the circuit board 40 controls the FET (Field Effect Transistor) provided on the sensor chip 33 for selecting the temperature difference sensor 33n, sequentially selecting each temperature difference sensor 33n and sequentially acquiring the electromotive force V from each selected temperature difference sensor 33n. Alternatively, the circuit board 40 is connected to each temperature difference sensor 33n via the signal transmission unit 50 to acquire the electromotive force V from each temperature difference sensor 33n. The circuit board 40 also acquires the reference temperature Tc detected by the temperature sensor 34 via the signal transmission unit 50 as an electrical signal.

[0044] The circuit board 40 performs analog-to-digital conversion on the acquired electromotive force V and reference temperature Tc, and calculates the value of the converted electromotive force V and reference temperature Tc based on the above formula (2) (Tt= 4 √(V / α+Tc 4 ) relationship, derives the surface temperature of the measurement object 95n, that is, the measurement object temperature Tt. The circuit substrate 40 substitutes the converted electromotive force V and the reference temperature Tc into the formula (2) prepared in advance in the memory, or refers to the table representing the relationship of the formula (2) prepared in advance in the memory based on the converted electromotive force V and the reference temperature Tc, and derives the measurement object temperature Tt. The circuit substrate 40 derives the measurement object temperature Tt for each temperature difference sensor 33n. The coefficient α of the formula (2) takes different values ​​depending on the value of the electromotive force V. Therefore, the circuit substrate 40 obtains the actual value of the coefficient α using a function prepared in advance in the memory, or obtains the actual value of the coefficient α by referring to a table prepared in advance in the memory.

[0045] The circuit board 40 generates a thermal image representing the temperature distribution of each measurement object 95n based on the measurement object temperature Tt derived from each temperature difference sensor 33n, and outputs the generated thermal image to the air conditioning system S via wireless or wired communication. The air conditioning system S controls the room temperature of the room 90 based on the thermal image, that is, the surface temperature of the measurement object measured by the temperature measuring device 10.

[0046] The heat insulating member 60 is arranged in the frame 20 and between the sensor device 30 and the circuit substrate 40 to insulate the sensor device 30 from the heat emitted from the circuit substrate 40. The heat insulating member 60 has a heat insulating layer 61 such as an air layer or a vacuum layer inside. The heat insulating member 60 can also be formed of a suitable heat insulating material such as glass wool or polyurethane foam. The signal line of the signal transmission part 50 connected to the sensor device 30 and the circuit substrate 40 passes through the heat insulating member 60. The heat insulating member 60 is formed into a cylindrical or polygonal shape with a closed upper end covering the sensor device 30 from above, that is, a cup shape. The cup-shaped heat insulating member 60 is arranged in the internal space R of the frame 20 and separates the space R1 where the sensor device 30 is located and the space R2 where the circuit substrate 40 is located. As a result, the space R1 and the space R2 are separated by the heat insulating member 60, and the heat emitted by the circuit substrate 40 is not transmitted to the sensor device 30 or is difficult to be transmitted to the sensor device 30. Alternatively, the heat insulating member 60 may cover the sensor device 30 in a shape so as to be in contact with the sensor device 30. In this case, the space R1 does not include the space around the sensor device 30.

[0047] Here, the effects of this embodiment are described. As described above, if the temperature of the reference junction D1, that is, the reference temperature Tc, is brought close to the measurement object temperature Tc to reduce the electromotive force V, the influence of the coefficient α on the measurement object temperature Tt becomes smaller. As a result, the measurement accuracy of the measurement object temperature Tt is improved when the measurement object 95n is a non-heat-generating body having a surface temperature in equilibrium with the room temperature. However, in the prior art, the heat emitted by the circuit substrate 40 heats the reference junction D1 of the temperature sensor device 30, which is affected by the room temperature in the room 90 and becomes the same temperature as the room temperature, thereby reducing the above-mentioned measurement accuracy. In this embodiment, since a heat insulating member 60 is provided between the sensor device 30 and the circuit substrate 40 to insulate the sensor device 30 from the heat emitted from the circuit substrate 40, it is possible to prevent the heat from being transferred to the sensor device 30 when the circuit substrate 40 is heated, or to prevent the heat from being transferred to the sensor device 30 when the circuit substrate 40 is heated. Therefore, the reference junction D1 of the sensor device 30 is less likely to heat up, and the reference temperature Tc is maintained close to room temperature, so that the measurement target temperature Tt of the non-heat-generating body, that is, the surface temperature of the non-heat-generating body, can be measured with high accuracy.

[0048] Furthermore, the temperature measuring device 10 in this embodiment can simultaneously measure the surface temperatures of various objects such as the floor 95A, table 95B, and person 95C in the room 90 using a plurality of temperature difference sensors 33n. Typically, non-heat-generating bodies such as the floor 95A and table 95B occupy most of the room 90, while heat-generating bodies 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 can be measured with high precision. In addition, in the air conditioning of the room 90, the air conditioner of the air system is sometimes controlled based on the average temperature Tt of the respective measurement object temperatures of all the measurement objects 95n. Since non-heat-generating bodies occupy a large proportion of the total measurement objects 95n, according to this embodiment, a high-precision average temperature can also be obtained.

[0049] Furthermore, the sensor device 30 measures the surface temperature of the measurement object 95n using its own temperature, i.e., the reference temperature Tc, as a reference. Therefore, it was previously believed that even if the sensor device 30 was heated, the measurement accuracy of the surface temperature (the measurement object temperature Tt) would not be affected. In other words, the thermal insulation member 60 is unnecessary. As described above, this embodiment specifically incorporates the thermal insulation member 60, taking into account that heating of the sensor device 30 by the circuit substrate 40 reduces the measurement accuracy of the surface temperature of non-heat-generating objects, which are often the measurement objects in air conditioning temperature measurements.

[0050] Furthermore, in addition to infrared radiation emitted from the measurement target 95n, the sensor device 30 is also incident with infrared radiation reflected from the measurement target 95n. This reflected infrared radiation is generated by the radiant energy of the room temperature (ceiling 91, walls, etc.). By setting the reference temperature Tc of the sensor device 30 close to the room temperature of the room 90, the reflected infrared radiation can be eliminated when measuring the measurement target temperature Tt, thereby improving the accuracy of temperature measurement.

[0051] [Second embodiment]

[0052] Next, refer to Figure 3 The temperature measuring device 110 of the second embodiment will be described. The following description will focus on portions different from the first embodiment, and components identical or similar to those of the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted as appropriate.

[0053] like Figure 3As shown, the temperature measuring device 110 includes a heat insulating member 160 in place of the heat insulating member 60 of the first embodiment. Heat insulating member 160 is formed in a plate shape that vertically 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, thereby separating space R1 from space R2. Even with this shape of heat insulating member 160, heat generated by the circuit board 40 is not transferred to the sensor device 30, or is difficult to transfer to the sensor device 30, thereby achieving the same effects as the first embodiment.

[0054] An opening 21B that connects the interior of room 90 with space R1 may be provided in a portion 21C of housing 20 of temperature measuring device 110 that defines space R1 and is adjacent to the interior of room 90 (here, a portion of bottom plate 21 located inward of cup-shaped member 22). Air from room 90 is introduced into space R1, where sensor device 30 is located, through opening 21B, thereby bringing the temperature of sensor device 30 or reference junction D1 closer to the room temperature in room 90. The number of openings 21B is arbitrary, but multiple openings 21B may be provided to facilitate the flow of air between room 90 and space R1.

[0055] Alternatively, an opening 22A may be provided in a portion (here, the upper side wall of the cup-shaped member 22) of the housing 20 that demarcates space R2 and contacts the outside of the room 90 (here, the interior of the ceiling 95). This opening connects the outside of the room 90 (i.e., the back surface of the ceiling 95) to the space surrounding the circuit board 40 in space R2. Heat generated by the circuit board 40 is discharged through this opening 22A to the back surface of the ceiling 91. Consequently, heat generated by the circuit board 40 is not transferred to the sensor device 30, or is less likely to be transferred to the sensor device 30, and the reference temperature Tc can be brought closer to room temperature.

[0056] Two openings 22A are arranged on the sides of the circuit board 40, facing the side walls of the cup-shaped member 22. This creates an airflow that enters space R2 from outside the housing 20 through one of the two openings 22A and then flows out through the other opening 22A. As a result, heat generated by the circuit board 40 is not transferred toward the heat insulating member 160 and the sensor device 30, and is not or is difficult to transfer to the sensor device 30.

[0057] [Third embodiment]

[0058] Next, refer to Figure 4 The temperature measuring device 210 of the third embodiment will be described. The following description will focus on portions different from the first and second embodiments, and components identical or similar to those of the first and second embodiments are denoted by the same reference numerals and their descriptions are omitted as appropriate.

[0059] The temperature measuring device 210 of the third embodiment includes a heat insulating member 260 in place of the heat insulating member 60. The heat insulating member 260 is a heat insulating member that separates the spaces R1 and R2. It includes a through-hole 261 that connects the spaces R1 and R2, and a door 262 that opens and closes the through-hole 261. When the door 262 is opened, at least a portion of the through-hole 261 is exposed. The heat generated by the circuit board 40 is transferred to the sensor device 30 via the through-hole 261. Furthermore, a drive device 280 is provided to drive the door 262. The drive device 280 may be, for example, a linear motor that opens and closes the through-hole 261 by moving the door 262 laterally. The drive device 280 is controlled by the circuit board 40.

[0060] If the measurement target 95n is, for example, floor 95A with floor heating, then during floor heating operation, floor 95A is higher than the room temperature of room 90. In this case, if the reference temperature Tc approaches the room temperature, the electromotive force V increases, potentially increasing the measurement error of the measurement target temperature Tt. Therefore, when the electromotive force V is detected or the measurement target temperature Tt of the measurement target 95n, as derived above, exceeds a predetermined reference, the circuit board 40 controls the drive device 280 to open the door 262 and thereby expose the through-hole 261. This allows heat generated by the circuit board 40 to be transferred to the sensor device 30 via the through-hole 261, causing the reference temperature Tc to rise, approaching the surface temperature of the floor 95A (the measurement target temperature Tt) generated by the floor heating. Consequently, the electromotive force V decreases.

[0061] For example, the circuit board 40 may determine whether the measured target temperature Tt (or, in the case of the temperature range, the average value) of the largest area in the thermal image, among areas where measured target temperatures Tt of the same temperature or within the same temperature range are concentrated, exceeds a predetermined threshold. When the circuit board 40 determines that the predetermined threshold has been exceeded, it may determine that the measured target temperature Tt derived as described above has been detected to be higher than a predetermined reference, thereby controlling the driver 280. Furthermore, when the circuit board 40 detects that a switch for floor heating, etc., is turned on, for example, upon receiving a signal from an external source indicating this, it may determine that the measured target temperature Tt has been detected to be higher than a predetermined reference (including a potential increase in the future), thereby controlling the driver 280. The circuit board 40 may also control the position of the door 262 so that the opening of the through-hole 261 increases as the measured target temperature Tt increases (including by increasing the opening in stages depending on the range within which the measured target temperature Tt falls). The circuit board 40 may control the driver 280 based on the electromotive force V instead of based on the measured target temperature Tt. In this case, the measurement target temperature Tt described above is replaced by the electromotive force V.

[0062] The number of through holes 261 and the like is arbitrary, and a plurality of through holes 261 and the like may be provided. The door 262 is provided to open and close in conjunction with an operating member protruding outside the housing 20, for example, or may be opened and closed manually by a user.

[0063] As shown in this embodiment, by assuming that the measurement object 95n is a heating element, etc., when the measurement object temperature Tt is different from the room temperature, the heat generated by the circuit substrate 40 is transferred to the sensor device 30, so that the reference temperature Tc is close to the measurement object temperature Tt, thereby measuring the surface temperature of the measurement object (heating element) with high precision.

[0064] [Modification]

[0065] The above-described embodiments may be modified. For example, the shape and number of each component of the temperature measuring devices 10, 110, and 210 (hereinafter also referred to as the temperature measuring device 10, etc.) are arbitrary.

[0066] The relationship used when the circuit substrate 40 derives the measurement object temperature Tt based on the electromotive force V and the reference temperature Tc is not limited to the above-mentioned formula (1) and formula (2). For example, the above-mentioned relationship can be any relationship as long as it is substantially the relationship of the above-mentioned formula (1) and formula (2), and the fourth power and the fourth root of the above-mentioned formula (1) and formula (2) can also be the 3.9th power and the 3.9th root. In addition, other formulas can also be used. As long as the measurement object temperature Tt is derived based on the electromotive force V and the reference temperature Tc, the derivation accuracy of the measurement object temperature Tt will not be higher than the measurement accuracy of the reference temperature Tc as the basis, as in the case described above. Moreover, when the measurement object temperature Tt is derived based on the electromotive force V, the larger the electromotive force V, the larger the measurement error of the measurement object temperature Tt. Therefore, even in the case where the measurement object temperature Tt is derived by a relationship of a formula other than the above-mentioned formula (1) and formula (2), the above-mentioned effect of the heat insulating member 60, etc. can be obtained.

[0067] The temperature measuring device 10, etc. can be installed at any location within the room 90 (indoors). The arbitrary location includes structures such as walls, floors, and pillars, in addition to the ceiling 91 that constitutes the room 90. As in the above-described embodiment, the temperature measuring device 10, etc. can be installed, for example, by being embedded in an arbitrary structure. The installation direction of the temperature measuring device 10 is also arbitrary. In the above-described embodiment, the top and bottom can be any direction as long as the side to be measured is the bottom and the opposite side is the top. In addition, the sensor device 30, such as the temperature measuring device 10, can also include a single temperature difference sensor 33n instead of multiple ones.

[0068] [Scope of the Invention]

[0069] While the present invention has been described above with reference to the embodiments and variations, the present invention is not limited to the embodiments and variations described above. For example, the present invention encompasses various modifications to the embodiments and variations described above that are understandable to those skilled in the art within the scope of the technical concept of the present invention. The various configurations listed in the embodiments and variations described above may be appropriately combined within the scope of non-inconsistency.

[0070] Explanation of symbols

[0071] 10, 110, 210…temperature measuring device, 20…frame, 21B, 22A…opening, 30…sensor device, 33…sensor chip, 33n…temperature difference sensor, 34…temperature sensor, 40…circuit board, 60, 160, 260…heat insulating member, 95, 95n…measurement object, 95A…floor, 95B…table, 95C…person, 261…through hole, 262…door, 280…drive device, 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, the temperature measuring device comprising: a sensor device comprising a temperature difference sensor and a contact temperature sensor, wherein the temperature difference sensor comprises a reference junction and a hot junction heated by infrared radiation from the measurement object and converts a temperature difference between the reference junction and the hot junction into an electromotive force, and the contact temperature sensor detects the temperature of the reference junction; a circuit board configured to derive 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 frame for accommodating the sensor device and the circuit substrate; as well as a heat insulating member disposed within the frame and between the sensor device and the circuit substrate to insulate the sensor device from heat emitted from the circuit substrate; The heat insulating member separates a first space where the sensor device is located from a second space where the circuit board is located in the space within the frame. The heat insulating member includes a through hole connecting the first space and the second space and a door for opening and closing the through hole, and the heat insulating member is configured so that when the door is opened and at least a portion of the through hole is exposed, heat generated by the circuit substrate is transferred to the sensor device through the through hole. It also includes a driving device for driving the door, The circuit board controls the drive device to open the door when the electromotive force or the derived surface temperature of the measurement object is detected to be higher than a predetermined reference.

2. The temperature measuring device according to claim 1, wherein The housing includes a first opening that allows communication between the interior of the chamber and a space surrounding the sensor device in the first space.

3. The temperature measuring device according to claim 2, characterized in that The housing includes a second opening that allows communication between the outside of the room and the space surrounding the circuit board in the second space.

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

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