JP7609679B2 - Temperature Measuring Device - Google Patents

Description

The present invention relates to a temperature measuring device for air conditioning that measures the surface temperature of an object to be measured indoors.

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

A conventional temperature measurement 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 the 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, which is the temperature of the reference junction. The circuit board derives the measurement object temperature Tt, which is the surface temperature of the measurement object, based on the electromotive force V converted by the temperature difference sensor and the reference temperature Tc detected by the temperature sensor.

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)

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

JP 2020-56546 A

After extensive research into the above-mentioned temperature measuring device, the inventors discovered the following problems, which led them to invent the present invention. These issues are described in detail below.

First, referring to the above formulas (1) and (2), when the electromotive force V=0, that is, when the reference temperature Tc and the temperature to be measured Tt are equal, the coefficient α has no effect on the derivation of the temperature to be measured Tt. Conversely, the larger the absolute value of the electromotive force V, the greater the effect of α on the derived temperature to be measured 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, errors are inevitably generated in the coefficient α. For these reasons, if the reference temperature Tc is brought closer to the temperature to be measured Tt and the electromotive force V is reduced, the effect of the coefficient α on the temperature to be measured Tt is reduced, and as a result, the measurement accuracy of the temperature to be measured Tt is improved.

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 will be 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 desirable to accurately identify the surface temperature of the non-heating object in the room in the above-mentioned equilibrium state using a 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.

Considering the above assumptions, if we consider conventional temperature measurement devices, in conventional temperature measurement devices, when the circuit board is not generating heat, the temperature of the sensor device or 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 emitted by the circuit board is trapped inside the housing and the sensor device warms up, resulting in the reference temperature Tc rising and moving 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.

The present invention was made in consideration of the above points, and aims to accurately measure the surface temperature of non-heat-generating objects in a room.

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 indoors, and includes a sensor device including a temperature difference sensor that has a reference junction and a hot junction that is 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 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 air that moves the 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 has an exhaust port through which the air from the fan passes.

The housing may be provided with an air intake that takes in air from outside the housing when the wind is generated by the fan.

The device may further include 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 may separate a first space in 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.

The circuit board may 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 standard.

The sensor device may 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 electromotive forces converted by each of the plurality of temperature difference sensors and the temperature of the reference junction detected by the temperature sensor.

According to the present invention, the surface temperature of non-heat-generating objects in a room can be measured with high accuracy.

FIG. 1 is a diagram showing a schematic structure of a temperature measuring device according to a first embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the temperature difference sensor shown in FIG. FIG. 3 is a diagram showing a schematic structure of a temperature measuring device according to a second embodiment of the present invention. FIG. 4 is a diagram showing a schematic structure of a temperature measuring device according to a modified example of the present invention.

[First embodiment]
A temperature measuring device 10 according to a first embodiment of the present invention will be described with reference to Figures 1 and 2. As shown in Figure 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 to control 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 Figure 1 is drawn large and is actually much smaller.

The temperature measuring device 10 measures the surface temperature of the objects present within its own measurement range W, that is, the floor 95A, the desk 95B, and the group of people 95C in the example of FIG. 1, as the measurement objects 95 for each divided range Wn. In other words, the temperature measuring device 10 measures the surface temperature of each of the measurement objects 95n, with each part of the measurement object 95 divided by the divided range Wn as the 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. When viewed from the top and bottom, the divided ranges Wn and the measurement targets 95n are arranged in a matrix, for example, 16 x 16.

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

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 onto 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, which is a polygonal tube or cylinder with a closed upper end and whose lower end is attached to the bottom plate 21, and 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 has an intake port H1 that introduces air from within the room 90 into the housing 20. The top of the cup-shaped member 22 has an exhaust port H2 that exhausts air from within the housing 20 to the ceiling space 95.

The sensor device 30 performs infrared sensing and the like to measure the surface temperature of the 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 depicted diagrammatically.

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 object 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.

The sensor chip 33 includes a plurality of temperature difference sensors 33n arranged in a matrix corresponding to the plurality of measurement objects 95n. 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 light from the measurement object 95n that is 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.

The temperature difference sensor 33n includes a sensing element M consisting of two types of metal wires M1 and M2 (thermocouples) connected alternately. The metal wires M1 and M2 are formed of different materials. The reference junction D1 includes a set of every other connection point C of the two types of metal wires M1 and M2. The hot junction D2 includes a set of the remaining connection points C of the multiple connection points C. Furthermore, the hot junction D2 includes a heat generation layer L that absorbs infrared light collected by the optical system 32 and generates heat. The heat generation layer L heats the connection points C of the hot junction D2. The heat generation 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 generation layer L out of the light that passes through the through hole of the housing 31.

When 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 way, 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.

The temperature sensor 34 is a contact-type temperature measuring element such as a thermistor. The temperature sensor 34 contacts a specific portion of the sensor chip 33 and detects the temperature of the specific portion. This specific portion is a portion that has the same temperature as the temperature of the reference junction D1. The temperature sensor 34 detects the temperature of the specific 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.

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 differs from room temperature, it is heated or cooled by the room temperature, and has a temperature approximately the same as the room temperature within the room 90.

The circuit board 40 includes a board, wiring mounted on the board, and various electronic elements, 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), memory, resistors, and capacitors. Such a circuit board 40 may generate heat during 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.

The circuit board 40 acquires the electromotive force V, which is the temperature difference converted by each temperature difference sensor 33n of the sensor chip 33, in the form of an electrical signal via a signal transmission unit 50 having a plurality of signal lines that transmit signals exchanged between the sensor device 30 and the circuit board 40. The circuit board 40 may control a FET (Field Effect Transistor) 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 the reference temperature Tc detected by the temperature sensor 34 in the form of an electrical signal via the signal transmission unit 50.

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

The circuit board 40 generates a thermal image showing the temperature distribution for each measurement object 95n based on the measurement object temperature Tt derived for each temperature difference sensor 33n, and outputs the generated thermal image to the air conditioning system S wirelessly or via a wired connection. 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 object measured by the temperature measuring device 10.

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 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 this 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.

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 high 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 higher than a predetermined threshold value measured by the temperature sensor. Furthermore, the circuit board 40 may increase the rotation speed of the fan 60 as its own temperature increases (including a mode in which the rotation speed 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 at all times in order to reduce the processing load on the circuit board 40 and reduce heat generation.

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 closer 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 warmed the reference junction D1 of the sensor device 30, which is at a temperature equivalent to room temperature due to the influence of the room temperature in the room 90, 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 temperature Tt of the non-heat-generating body, i.e., the surface temperature of the non-heat-generating body, is measured with high accuracy.

Furthermore, the temperature measuring device 10 in this embodiment can simultaneously measure the surface temperatures of various types of objects in the room 90, such as the floor 95A, desk 95B, and person 95C, using multiple temperature difference sensors 33n. Generally, non-heat-generating objects such as the floor 95A and desk 95B occupy most of the room 90, while heat-generating objects such as the person 95C occupy only a small area of the room 90. For this reason, in this embodiment, the surface temperatures of most of the room 90 are measured with high accuracy. In addition, when air-conditioning 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, this embodiment can also obtain an accurate average temperature.

In addition, 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 (measurement target temperature Tt) even if the sensor device 30 was heated. In other words, there was no need to provide a 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 non-heat-generating bodies that are often the measurement target in temperature measurements for air conditioning, and therefore deliberately employs the fan 60.

Furthermore, in addition to the infrared rays emitted from the measurement object 95n, the infrared rays reflected by the measurement object 95n are also incident on the sensor device 30. This reflected infrared rays is 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 canceled out when measuring the measurement object temperature Tt, improving the accuracy of the temperature measurement.

[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.

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 be transmitted by 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.

As shown in FIG. 3, an opening 21D that connects the inside of the room 90 to the space R1 may be provided in a portion 21C (here, a portion inside the cup-shaped member 22 of the bottom plate 21) of the internal space R of the housing 20 of the temperature measuring device 110 that divides the space R1 and is adjacent to the room 90. The opening 21D allows air from the room 90 to be introduced into the space R1 in which the sensor device 30 is located, thereby making it possible to bring the temperature of the sensor device 30 or the reference junction D1 closer to the room temperature of the room 90. The number of openings 21D is arbitrary, but it is preferable to provide multiple openings 21D so that air can easily flow in and out between the inside of the room 90 and the space R1.

As shown in FIG. 4, the insulating member 170 may be formed in a plate shape that divides the internal space R into an upper and lower space R1 where the sensor device 30 is located and a space R2 where the circuit board 40 is located, separating the spaces R1 and R2. In such a case, the air intake H1 is formed in a portion of the cup-shaped member 22 of the housing 20 that divides the space R2. The air intake H1 should be located at a position where the circuit board 40 is located between the air intake H1 and the exhaust port H2. This allows the wind F to effectively dissipate heat from the circuit board 40 to the outside of the housing 20.

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

[Modification]
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.

[Modification 1]
The circuit board 40 may control the rotation speed of the fan 60 (wind 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 generates heat due to the floor heating. Therefore, the electromotive force V becomes smaller.

The circuit board 40 may, for example, determine whether the measurement target temperature Tt (in the case of the temperature range, the average value, etc.) of the largest area among the areas in the thermal image where the measurement target temperatures Tt are gathered, which have the same temperature or are within the same temperature range, has exceeded a predetermined threshold. When the circuit board 40 determines that the measurement target temperature Tt derived as described above is higher than a predetermined standard when it has determined that the measurement target temperature Tt has exceeded the predetermined threshold, it 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 switch of the floor heating or the like has been turned 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 standard (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).

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.

[Modification 2]
The relationship used when the circuit board 40 derives 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.

[Modification 3]
The temperature measuring device 10 and the like may be installed at any location within the room 90 (inside the room). The arbitrary 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 and the like 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 the bottom and the opposite side is the top. Furthermore, the sensor device 30 such as the temperature measuring device 10 may have one temperature difference sensor 33n instead of multiple ones.

[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.

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 target, 95A...floor, 95B...desk, 95C...person, R...internal space, R1, R2...space.

Claims (4)

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. 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 . 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 . The sensor device includes a plurality of the temperature difference sensors,
the circuit board derives 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 temperatures of the reference junctions detected by the temperature sensors.
A temperature measuring device according to any one of claims 1 to 3 .

Images