JPH07120329A - Radiation sensor - Google Patents

Abstract

PURPOSE:To make difference of radiation factors of a radiation-detecting part and a radiation reference part large to improve a radiation-detecting sensitivity, by covering a resistance of a metallic thin film constituting the radiation reference part with a material of a smaller radiation factor than that of a black body. CONSTITUTION:An insulating film 2 is formed on a silicon substrate 1, onto which a temperature sensor 3, an air flow sensor 4, a radiation sensor and a moisture sensor 6 are set. The radiation sensor 5 has a radiation reference part 5b consisting of one of a pair of titanic toxin film resistances, and a radiation-detecting part, 5a formed by coating the other thin film resistance with a black body material 7. A difference of radiation factors of the titatic material of the reference part 5b and tone black body material 7 is converted into a resistance change to detect a radiation in this radiation sensor. The reference part 5b is coated with a material of a smaller radiation factor than that. of the material 7, e.g. sheet 9 of an aluminum foil. The sheet 9 has an approximately 0.1 radiation factor, and therefore a difference of the factor from a 0.9 factor of the material 7 is 0.8. A radiation-detecting sensitivity is accordingly improved about 3 times in comparison with a conventional sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation sensor suitable for detecting the amount of radiation in an air-conditioned space.

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application No. 4-270620.
The composite sensor filed by the patent is shown in FIG.
In FIG. 2, reference numeral 1 is a silicon substrate, and an air temperature sensor 3, an air flow sensor 4, a radiation sensor 5 and a humidity sensor 6 are provided on an insulating film 2 formed on the silicon substrate.

The temperature sensor 3 is composed of a thin film resistor and converts a temperature change into a resistance change of the thin film resistor to detect it.

The airflow sensor 4 comprises an airflow detection unit 4a for detecting the airflow and an airflow temperature correction unit 4b for correcting the detected airflow with respect to the air temperature. The airflow detection unit 4a and the airflow temperature The correction units 4b are both made of thin film resistors having the same shape. The airflow sensor 4 catches a change in the thermal conductivity of the atmosphere due to the airflow as a temperature change, and finally converts it into a resistance change of the thin film resistance for detection.

In the radiation sensor 5, one of a pair of thin-film resistors made of titanium material serves as a radiation reference portion 5b, and the other serves as a radiation detection portion 5a by covering with a black body material 7, and a titanium material constituting the radiation reference portion 5b. And the radiation coefficient of the black body material 7 that covers the radiation detection unit 5a are converted into resistance changes (heating temperature difference) to detect radiation.

The temperature sensor 6 detects humidity by a change in electrostatic capacitance of the moisture sensitive material 6a held between the electrodes 6b. 8 is a windshield, which is an air temperature correction unit 4b of the air flow sensor 4 and a radiation sensor 5.
Is covered.

[0007]

In the above conventional radiation sensor, since the radiation reference portion 5b is made of a titanium material, its radiation coefficient is as high as about 0.6 to 0.8, and therefore the radiation detection portion 5a is covered. There is a problem that the radiation detection sensitivity is low because there is a small difference between the radiation coefficient 0.9 of the black body material and the radiation coefficient 0.6 to 0.8 of the radiation reference section 5b.

[0008]

SUMMARY OF THE INVENTION The present invention has been invented to solve the above problems, and its gist is to provide one of a pair of metal thin film resistors provided on a substrate as a radiation reference. Part, and the other part is covered with a black body material, and the radiation sensor is used as a radiation detecting part.One of the metal thin film resistors forming the radiation reference part is covered with a material having a radiation coefficient sufficiently smaller than that of the black body material. The radiation sensor is characterized by.

The coating material having a sufficiently small radiation coefficient can be used as an aluminum foil sheet.

[0010]

In the present invention, the radiation detection sensitivity is improved because the difference in radiation coefficient between the radiation reference section and the radiation detection section becomes large.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENT One embodiment of the present invention is shown in FIG. The radiation reference portion 5b is covered with a material having a radiation coefficient sufficiently smaller than that of the black body material 7, for example, an aluminum foil sheet 9. Other configurations are similar to those of the conventional one shown in FIG. 2, and corresponding members are designated by the same reference numerals.

Therefore, the radiation coefficient of the aluminum foil sheet 9 is
Since it is about 0.1, and the difference between the emissivity coefficient 0.9 of the black body material 7 and the emissivity coefficient 0.1 of the aluminum foil sheet 9 is 0.8, that of the conventional one (the difference in emissivity between the black body material and the titanium material). It is about 3 times that of 0.3), and the radiation detection sensitivity is also about 3 times that of the conventional one.

[0013]

According to the present invention, since the metal thin film resistor forming the radiation reference portion is covered with a material having a radiation coefficient sufficiently smaller than that of the black body material, the radiation detecting portion and the radiation detecting portion can be used even though the structure is simple and inexpensive. Since the difference in the radiation coefficient of the reference part can be increased, the radiation detection sensitivity can be greatly improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an example of a conventional radiation sensor.

[Explanation of symbols]

 1 Substrate 5 Radiation sensor 5a Radiation detection part 5b Radiation reference part 7 Blackbody material 9 Aluminum foil sheet

Claims (2)

[Claims] 1. A radiation sensor, wherein one of a pair of metal thin-film resistors provided on a substrate serves as a radiation reference portion and the other serves as a radiation detection portion by coating with a black body material, the radiation reference portion being configured. A radiation sensor characterized in that one metal thin film resistor is coated with a material having a radiation coefficient sufficiently smaller than that of the black body material. 2. The radiation sensor according to claim 1, wherein the coating material having a sufficiently small radiation coefficient is an aluminum foil sheet.