JPS59225321A - Optical fiber type radiation thermometer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a fiber optic radiation thermometer that can be remotely measured.

[Background technology]

A radiation thermometer is a device that remotely measures relatively low temperatures of about 0° C. to 100° C.

This method detects infrared rays with a wavelength of about 8 to 12 μm emitted from the object to be measured, and calculates and measures the temperature from the law of black body radiation.

In recent years, there have been many attempts to use infrared optical fibers as light guides for transmitting infrared rays, and to take advantage of their flexibility to measure the temperature inside or inside objects with complex shapes. Ttsuchiru.

This temperature measurement method using an optical fiber is characterized in that it can be measured in an electrically insulated state, and by reducing the diameter of the fiber, it is possible to measure temperatures in an extremely small range.

[Disadvantages of conventional radiation thermometers]

However, like conventional radiation thermometers, with a radiation thermometer using an optical fiber as a light guide, it is impossible to know the true temperature of the object to be measured without performing the complicated operation of calibrating the detected temperature using the emissivity of the object. Ta.

[Object of the present invention]

The present invention aims to eliminate the above-mentioned drawbacks of conventional radiation thermometers. That is, an object of the present invention is to provide an optical fiber type radiation thermometer that can measure the emissivity without calibrating the emissivity depending on the difference between the objects to be measured.

[Configuration of the present invention]

In order to achieve the above object, the present invention fixes a minute piece having a high emissivity with a fixing material having a low emissivity. That is, the present invention is characterized in that a minute piece having a high emissivity is arranged at one end of an optical fiber in alignment with the optical axis of the optical fiber, and this is fixed with a fixing material having heat insulating properties and a low emissivity. This is an optical fiber type radiation thermometer.

In the present invention, the minute pieces are made of a material having a high emissivity, preferably a material having an emissivity of 0.8 or more. This kind of material is Ni2O%, 0r2
5% Fe and 55% Fe with an oxidized surface (emissivity 090) or carbon (emissivity o, s
1) can be mentioned. Furthermore, in the present invention, the fixing material is made of a material that is heat insulating and has a low emissivity, preferably a material that has an emissivity of 0.05 or less. For this type of material, non-metallic materials such as quartz glass and alumina are used as heat insulating materials, and the inner surface is made of low emissivity materials such as zinc (emissivity o, 05'l tin (emissivity o, 043), lead (emissivity o, 043), etc. It is preferable to use a material coated with a material such as O, OS).

In addition, in the present invention, in order to improve the response to temperature changes of the object to be measured, it is preferable that the minute pieces be as small as possible, for example, in the shape of a disk of 0.5φ and 0.2t. is suitable.

The present invention has been described above, and FIGS. 1 and 2 are explanatory diagrams of how the temperature of an object to be measured is measured using the optical fiber type radiation thermometer of the present invention.

On the side of the measured object E of the optical fiber B, which serves as a light guide path,
A minute piece A with high emissivity is fixed.

Since the minute piece A is minute, it reaches a state of thermal equilibrium with the object to be measured E as soon as it comes into contact with it.
It emits infrared rays as a black body with the same temperature as . The radiated infrared rays are transmitted through the optical fiber B, and the condensing lens C
All the way through, it enters the detection element. In this way, by measuring the temperature of the object to be measured E with the microscopic piece A at the tip of the fiber in contact with the object to be measured E, the detected temperature is calibrated based on the emissivity of the object to be measured E. Radiation temperature measurement is possible without any problems.

The holder F that encloses the small piece A is covered with a metal having a low emissivity to reduce the infrared rays emitted by the holder F and reduce measurement errors. G is a hollow part.

[Explanation of FIG. 2] FIG. 2 is an enlarged view of an optical fiber type radiation thermometer that is an embodiment of the present invention. In this figure, F is a holder made of quartz glass whose inner surface is coated with low emissivity materials such as zinc (emissivity O, OS), tin (emissivity O, 043), lead (emissivity O, 05), etc. It is. With such a structure, the infrared rays radiated from the inner low emissivity coating surface can be ignored. A is a high refractive index material N
i20%, 0r25%, Fe55% (emissivity 0.90'
), etc., or carbon (emissivity (0,81'), etc.), which contact the object to be measured and reach thermal equilibrium, which corresponds to the temperature of the object to be measured. Emit infrared rays with a constant high emissivity.The microscopic piece A is fixed by the thermally conductive soft quartz glass of the holder F.The microscopic piece A can be fixed with good heat insulation properties, and the small temperature change of the object to be measured can be prevented. Thermal equilibrium is reached accordingly.

In addition, it is preferable that the minute piece A is minute (,0,3φ, 0.2
It was made into a disk shape of t.

B is an optical fiber for transmitting the infrared radiation emitted from the minute piece A. The following experiments were conducted using optical fiber B having the above structure.

The object to be measured was a tungsten block (emissivity 0.02
4) Using a block (emissivity 087) made of an alloy of 80% Ni and 20% 0R whose surface has been oxidized, the tip of the optical fiber of the present invention (part A of the micropiece in Fig. 2) is brought into contact with this surface to form a microparticle. When the infrared rays emitted from A are transmitted through optical fiber B and the output is detected, even though the two blocks to be measured have different emissivities, the infrared rays detected by measurement using the thermometer of the present invention. External radiation dose is 0℃~
At the same temperature of 200°C, there was agreement within the error range.

1, the response to the temperature change of the object to be measured is 0.2 seconds, which is sufficiently fast, and the area to be measured is equal to the area 06φ of the minute piece A, making it possible to measure a sufficiently small range.

[Effects of the present invention]

As described in detail above, the present invention measures the temperature of the object to be measured through a minute piece whose emissivity is high and constant, so there is no need to calibrate the emissivity due to differences in the object to be measured. This results in significant measurable effects. By making the size of the microscopic particles smaller, the response speed of temperature measurement can be improved by reducing the size of the microscopic particles. This also has the effect of making it possible to measure the temperature of certain parts. In other words, the present invention eliminates the need to calibrate emissivity.
Furthermore, an excellent effect is produced in that the advantages of conventional radiation temperature measurement are maintained as they are.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of how the temperature of a measured object is measured using the optical fiber type radiation thermometer of the present invention, and Fig. 2 is an explanatory diagram of the optical fiber type radiation thermometer which is an embodiment of the present invention. An enlarged view of the image. A... Microscopic piece B... Optical fiber C... Condensing lens D... Detection element E... Measured object F... Holder G... Hollow agent inside 1) Bright Agent Ryo Hagiwara −

Claims (3)

[Claims] (1) An optical fiber characterized by arranging a microscopic piece with high emissivity at one end of the optical fiber in line with its optical axis, and fixing this with a fixing material that has heat insulating properties and low emissivity. type radiation thermometer. (2) The optical fiber type radiation thermometer according to claim 1, wherein the minute pieces are made of a material having an emissivity of 0.8 or more. (3) The optical fiber type according to claim 1, wherein the fixing material is made of a non-metallic material with good heat insulation properties, such as quartz glass or alumina, and the inner surface of the fixing material is coated with a low-radiation material. Radiation thermometer.