JPS6283629A - Optical temperature measuring sensor - Google Patents

Abstract

PURPOSE:To improve heat-resistance without deteriorating workability, by filling SF6 gas in a detecting means using a GaAs semiconductor and a gap of an optical fiber. CONSTITUTION:A cover-material 4 stripped optical fiber 3 is inserted into a sleeve 10 and bonded with bonding compound 11. And, the sleeve 10 is inserted into a protecting tube 19 and bonded with bonding compound 12. Next, optical fiber 3, protecting tube 19 are introduced into a glove box 30 and the box is filled with GaAs semiconductor. In this condition, spacer 7, holder 9 accommodated with a semiconductor 5 and a reflecting mirror, and a spacer 8 are inserted into the protecting tube 19 in process of assembly. And, a plugging cover 14 is inserted and bonded with bonding compound 13. For bonding agents 11-13, epoxy resin of excellent gas-tightness, high-temperature impact resistance and workability is used. In atmosphere of SF6, a heat decomposition point of epoxy resin is much higher than in the case air. Consequently, in the higher temperature, drop of the sensitivity in accompaniment with drop of permeability of the GaAs semiconductor by the heat decomposition of the bonding compound is insignificant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical temperature measurement sensor.

[Conventional technology]

A conventional optical temperature measurement sensor will be explained using the fourth factor.

The light emitted from the light emitting element (1) is transmitted through a beam splitter.
(2), is transmitted through the optical fiber (3), passes through the gap σ'), passes through the GaAs semiconductor (5), enters the reflecting mirror (6), and is reflected. The light reflected by the reflecting mirror (6) passes through the GaAs semiconductor (5) and enters the air 19.
When the optical fiber (3) is transmitted in the opposite direction, it is reflected by the beam splitter (2) in the right angle direction and sent to the light receiving element (4).
The light is received by Sleeve αQ is optical fiber (3)
The optical fiber (3) is fixed to the protective tube q1 by adhesive bonding (Uυ) so as to partially cover the coating material (4), and the adhesive % is attached to the protective tube side. It is fixed by fJa.

The GaAs semiconductor (5) is mounted on a holder (
9). The holder (9) is fitted into the protection tube (II) together with spacers (7) and (8), and is fixed so that it does not move with a stopper lid.The stopper tooth split Q is fixed to the protection tube bend with adhesive XCL3. has been done.

Also, air is contained in the voids as, ati, C17) and (to).

In a GaAs semiconductor, the transmitted light intensity (or transmittance) decreases with temperature due to the temperature dependence of the optical absorption edge wavelength. Therefore, the temperature was measured by placing a GaAs semiconductor in contact with or near the object to be measured, and detecting the intensity of the light reflected by the reflecting mirror (6) at the end of the light receiving element.

(Problems to be solved by the invention) Conventional optical temperature measurement sensors use epoxy adhesive in consideration of workability, and air is trapped inside the protective tube. When the temperature to be measured reaches a high temperature, the adhesive decomposes and the decomposed products adhere to the GaAs semiconductor, causing G
This has the problem of lowering the transmittance of the aAs semiconductor and lowering the sensitivity as a temperature sensor.

This invention has been made to solve the above problems.It has excellent heat resistance without impairing workability.
The purpose of the present invention is to provide this optical temperature measurement sensor.

[Means to solve the problem]

The optical temperature measurement sensor according to the present invention is characterized by filling the void inside the tube with sulfur hexafluoride gas every fX.

[Effect]

Sulfur hexafluoride gas prevents thermal decomposition of the epoxy adhesive at high temperatures, thereby preventing decomposition products from adhering to the GaAs semiconductor and reducing transmittance.

[Embodiments of the invention]

An embodiment of the optical temperature measurement sensor according to the present invention will be described using the first embodiment (a) and (1).

However, the structure of the mechanical parts after assembly is completed is exactly the same as the conventional optical temperature measurement sensor shown in the fourth example.
The air obstruction μs in the conventional optical temperature measurement sensor,
Qf$, Q7), Q8) contains sulfur hexafluoride (SF6)
) The gas is already filled. Items with the same number in the middle have exactly the same function.

The first part (a) shows the part to be assembled in air, where the sleeve (10) is fitted and bonded.

Next, put the optical fiber (3), which is in the process of being assembled, and the protective tube side into the glove box (■), and after evacuating the inside of the glove box, the SF6 gas is heated to the same pressure as atmospheric pressure.
Enclose it so you can understand. In this state, the protective tube side ζ spacer (7), the GaAs semiconductor (5), which is being assembled above,
and attach the reflector (6) 1. Fully insert the halter (9) and spacer (8). Then, use the adhesive shield (4) to glue everything together and the assembly work is complete.

Adhesive (l)J to prevent leakage of sulfur hexafluoride gas.
Ll'i+ uses a two-component epoxy resin that has excellent properties, heat resistance, and workability.

Next, the second and third graphs show the temperature reduction rates of epoxy resin in air and SF6 atmosphere. These characteristic curves are based on the adhesive cured product obtained by curing epoxy resin and 17 parts by weight of Ciba Geigy's Araldite GY260.100 parts by weight and Araldite HT951.10 parts by weight at room temperature for 72 hours. The results show the results of thermogravimetric analysis using a Shimadzu thermogravimetric analyzer under the conditions of a heating rate of 5°C/min in a sulfur hexafluoride atmosphere (flow ffiaom#/min) and a sulfur hexafluoride atmosphere (flow ffiaom#/min). ing. From these problems, 1 () of the initial superposition of epoxy resin
If we look for the % Ii, it is 2 in an air °4 environment.
80'C, whereas it is 420°C in a sulfur hexafluoride atmosphere. That is, it can be seen that the thermal decomposition temperature of the epoxy resin in a sulfur hexafluoride atmosphere is significantly higher than that in an air atmosphere.

Note that in this example, sulfur hexafluoride gas was used, and t,=
Or, the concentration of sulfur hexafluoride gas is 1 to 100% 6
A mixed gas of sulfur fluoride gas and nitrogen gas may also be used. Further, although this embodiment is of a reflection type in which one optical fiber is used as the input and output optical path, it goes without saying that a transmission type may be used in which two separate optical fibers are used as the input and output optical paths.

〔Effect of the invention〕

As described above, if the optical temperature measurement sensor according to the present invention is used, even at high temperatures, the sensitivity decrease due to the decrease in the transmittance of the GaAs semiconductor due to thermal decomposition of the adhesive is small, and the optical temperature measurement sensor with excellent heat resistance can be used. It is possible to provide a sensor for temperature measurement.

[Brief explanation of drawings]

The first lines (a) and (b) are the assembly parts of the optical temperature measurement sensor according to the present invention. , No. 4 is a sectional view showing the configuration of mechanical parts of the optical temperature measurement sensor according to the present invention and a conventional optical temperature measurement sensor. In the figure, (3) is an optical fiber, (5) is a GaAs semiconductor,
(6) is a reflective mirror, Uυ, @, (l: is glue, egg, west, surface, Q& is interdisciplinary hto, -6

Claims (1)

[Claims] (1) In an optical temperature measurement sensor that uses a gallium arsenide (GaAs) semiconductor as a detection means and an optical fiber as a transmission path, the gap between the detection means and the optical fiber is filled with sulfur hexafluoride (SF_6) gas. A unique optical temperature measurement sensor.