JPH02268235A - Radiation temperature sensor - Google Patents

Abstract

PURPOSE:To reduce the effect of radiation from a surrounding structure and to improve measuring accuracy and sensitivity by applying an infrared-ray reflecting film on the outer surface of a heat insulating material or on the outer surface of a case surrounding the heat insulating material. CONSTITUTION:The outer surface of a case 6 of a radiation temperature sensor other than a light receiving surface is coated with a sheet 7 which comprises a material for reflecting infrared rays at high efficiency (e.g. a smooth foil of aluminum or stainless steel). Thus, radiation from a surrounding structure 8 is not absorbed with the radiation temperature sensor but reflected with the infrared-ray reflecting sheet 7. Therefore, a heat insulating material 5 and the case 6 of the radiation temperature sensor 7 are hard to receive the effect of the radiation from the surrounding structure 8. Since the radiation temperature sensor and the surrounding structure 8 are separated with an air layer 10, heat conduction between both parts is poor. Thus the measuring accuracy and the sensitivity can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a device for reducing the influence of radiation (thermal radiation) between the radiant temperature sensor and surrounding structures that support and fix the radiant temperature sensor. Regarding.

[Prior Art] As described in Japanese Utility Model Application No. 63-58720, a conventional temperature sensor includes a heat receiving body made of a good thermal conductor, a heat sensitive element such as a thermistor fixed to the heat receiving body, and a temperature measuring device. It is composed of a protection plate that allows the transmission of radiant energy from the target and reduces the influence of wind. In addition, in addition to the heat-sensitive element, a heater element is attached to the heat-receiving body, as described in Utility Model Application Publication No. 62-133137.
There is a temperature sensor that is fixed and further includes a thermistor for detecting room temperature. All of these temperature sensors measure the radiant (thermal radiation) energy from the temperature measurement target without directly contacting the sensing part with the target.
Specifically, the temperature change of the heat receiving body due to the magnitude of radiant energy is converted into the temperature change of a heat sensitive element fixed to the heat receiving body and measured. A thermistor, which converts a temperature change into an electrical signal change, is often used as a heat-sensitive element. In any of the temperature sensors, a heat insulating material is provided on the back side of the heat receiving body, and the structure is such that heat transfer from the back side is suppressed.

When these temperature sensors are used in air conditioners, etc., they are often supported and fixed directly to the air conditioner's wooden board, as shown in Japanese Patent Laid-Open No. 61-149751, but As shown in Japanese Patent No. 40442, there is also an example in which a temperature sensor is supported on an air conditioner wooden board via a joint means.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, when a temperature sensor is incorporated into, for example, a recess of an air conditioner and supported and fixed, or installed via a joint, the temperature sensor is If measures to reduce the effects of radiation (thermal radiation) from structures, i.e. air conditioners, are not sufficiently taken and there is a large temperature difference between the temperature sensor and the surrounding structures, the effects of radiation (thermal radiation) There was a problem that the temperature measurement lacked accuracy because the influence could not be ignored.

An object of the present invention is to improve the accuracy of a temperature sensor by reducing the influence of radiation (thermal radiation) exerted by surrounding structures on the temperature sensor.

[Means for Solving the Problems] In order to achieve the above object, the gist of the present invention is as set forth in each claim.

[Function] According to the configuration of the present invention, radiation from other than the light-receiving surface is reflected and hardly affects the heat-receiving body of the radiant temperature sensor, so that the reliability of the measurement of the radiant temperature sensor is improved. .

[Embodiment] FIG. 1 shows an embodiment of the present invention. The radiant temperature sensor shown in FIG. 1 includes a heat-sensitive element 1 such as a thermistor, a heat-receiving body 2 to which the heat-sensitive element 1 is fixed, and an infrared-transparent protection plate 3 to prevent the heat-receiving body 2 from being directly exposed to surrounding wind. These heat receiving bodies 2. It has a structure in which infrared-transmissive protection plates 3 are sandwiched between gaskets 4 so that they do not come into direct contact with each other, and a heat insulating material 5 is layered on this from the back, and these are housed in a case 6. This radiant temperature sensor has a structure in which the surrounding structure It is supported by an object 8 (for example, an air conditioner wooden board) via a support means (not shown).

The heat-sensitive element 1 detects the temperature of the temperature measurement target facing the heat-receiving body 2 of the radiant temperature sensor by the temperature change of the heat-receiving body 2. At this time, the radiation from the measurement target to the heat-receiving body 2 is protected by infrared transparent transparent protection. It enters through plate 3. On the other hand, the surface other than the light-receiving surface of the radiant temperature sensor (the surface on the side where the protection plate 3 is present) is connected to the surrounding structure 8 that fixes and supports the radiant temperature sensor.
I am facing with. Therefore, the horizontally narrow temperature of the heat receiving body 2 of the radiant temperature sensor is affected by surface heat transfer from surfaces other than the light receiving surface and heat conduction from the contact area, but especially by the surrounding structures to the radiant temperature sensor. The influence of radiation from 8 cannot be ignored.

Therefore, in this embodiment, the outer surface of the case 6 of the radiation temperature sensor other than the light receiving surface is covered with a sheet 7 of a material (for example, a smooth aluminum or stainless steel foil) that reflects infrared rays at a high rate. Radiation from the surrounding structures 8 is reflected by the infrared reflective sheet 7 without being absorbed by the radiant temperature sensor, as indicated by arrows in FIG. therefore,
The heat insulating material 5 and case 6 of the radiant temperature sensor have the effect of being less susceptible to radiation from surrounding structures 8. Furthermore, since the radiant temperature sensor and the surrounding structure 8 are separated by the air layer 10, there is little heat conduction between them.

FIG. 2 shows another embodiment of the invention. The radiant temperature sensor shown in FIG. 2 has an infrared reflective sheet 7 coated on the inner surface of a heat insulating material 5, that is, the surface facing the heat receiving body 2, among the components of the radiant temperature sensor. The infrared reflecting sheet 7 reflects radiation from the heat sensitive element 1 and the heat receiving body 2 to the heat insulating material 5 as shown by the arrows in FIG. 2, and suppresses absorption into the heat insulating material 5.

Therefore, there is an effect that the heat-sensitive element 1 and the heat-receiving body 2, whose temperature changes due to radiation from the temperature measurement target, are less affected by radiation between them and the heat insulating material 5.

FIG. 3 shows that in the embodiment shown in FIG.
This is an embodiment in which the portion facing the radiant temperature sensor is coated with . The infrared reflective sheet 7 coated on the radiant temperature sensor side and the infrared reflective sheet 7' coated on the air conditioner 8 side reflect infrared rays from each other, and the radiant temperature sensor Not easily affected by radiation. Incidentally, numeral 11 in FIG. 3 is a vane plate that suppresses convection between the air layer 10 and the surrounding air of the air conditioner 8, thereby reducing heat transfer due to convection.

It is more effective if the outer surface of the case 6 of the radiant temperature sensor in the embodiment shown in FIG. 2 is also coated with an infrared reflective sheet. If used as a sensor, even higher effects can be obtained.

The air [10] shown in FIGS. 1 and 3 may be filled with a heat insulating material.

In each of the above embodiments, instead of using the infrared reflective sheet 7, the heat insulating material 5 or the case 6 in each radiant temperature sensor may be made of a material having a high infrared reflectance. It is possible to obtain the same effect as in each of the above-mentioned embodiments in which the reflective sheet 7 is covered.

Note that it is also possible to use a radiant temperature sensor with a structure in which the white plate of the heat insulating material constitutes the cylindrical plate of the temperature sensor without having a case on the outside of the heat insulating material, and in the case of such a structure,
It goes without saying that the infrared reflective sheet coated on the outer surface may be coated on the outer surface of the heat insulating white board, or the heat insulating material may be formed of a material having good infrared reflective properties.

FIG. 4 shows an embodiment in which the surface of the heat receiving body 2 opposite to the light receiving surface side is covered with an infrared reflective sheet 7''. This also prevents radiation from the surroundings other than the light receiving surface from This has the effect of reducing the impact on

Note that, instead of coating the surface of the surrounding structure 8 with an infrared reflective sheet, the surrounding structure 8 may be made of a material with good infrared reflectivity to achieve the same purpose.

[Effects of the Invention] According to the present invention, the influence of radiation from sources other than the temperature measurement target can be reduced, so that the measurement accuracy and sensitivity of the radiation temperature sensor can be improved. According to the present invention, in an air conditioner or the like in which a radiant temperature sensor is installed, it is possible to suppress radiation from surrounding structures such as the air conditioner to the radiant temperature sensor,
This has the effect that the measurement accuracy of the radiant temperature sensor is improved and its installation position can be determined freely.

[Brief explanation of drawings]

1 to 4 are cross-sectional views showing several embodiments of the present invention. 1... Heat sensitive element 2... Heat receiving body 3... Infrared transparent protective plate 4... Packing 5... Heat insulating material 6... Case

Claims (1)

[Scope of Claims] 1. A heat receiving body to which a heat sensitive element such as a thermistor is fixed, an infrared transparent protection plate disposed on the light receiving surface side of the heat receiving body, and surrounding the heat receiving body except for the light receiving surface side. 1. A radiant temperature sensor comprising a heat insulating material, characterized in that an infrared reflective coating is applied to the outer surface of the heat insulating material or the outer surface of a case surrounding the heat insulating material. 2. The radiant temperature sensor according to claim 1, wherein the inner surface of the heat insulating material is also coated with an infrared reflective coating. 3. The radiant temperature sensor according to claim 1 or 2, characterized in that instead of applying an infrared reflective coating to the heat insulating material or the case, the heat insulating material or the case itself is made of an infrared reflective material. 4. A radiation device that has a heat receiving body to which a heat-sensitive element such as a thermistor is fixed, an infrared-transmissive protection plate disposed on the light receiving surface side of the heat receiving body, and a heat insulating material surrounding the heat receiving body except for the light receiving surface side. A radiant temperature sensor, characterized in that the light-receiving surface side of the heat receiving body is coated with an infrared reflective coating on the reflective side. 5. In a surrounding structure in which the radiant temperature sensor according to claim 1, 2, 3 or 4 is mounted at intervals, an infrared reflective coating is applied to the surface of the surrounding structure facing the radiant sensor, or the surrounding structure is provided with an infrared reflective coating. A surrounding structure equipped with a radiant temperature sensor, characterized in that the structure is made of an infrared reflective material. 6. A surrounding structure equipped with a radiant temperature sensor according to claim 5, wherein the surrounding structure is a part of an air conditioner.