JPS59170738A - Temperature measuring device - Google Patents

Abstract

PURPOSE:To measure temp. at multiple points with an inexpensive device having simple constitution by utilizing the characteristic that the energy band gap of a semiconductor crystal changes with temp. CONSTITUTION:A light emitting source 1 transmits time dividedly and periodically repetitively (n+1) kinds of light having wavelengths lambda1, lambda2-lambdan, lambdan+1. The wavelengths of the energy band gaps of semiconductor crystals 3-1-3-n are lambda1, lambda2-lambdan. The output from a photodetector 4 detecting the light of the wavelength lambda1 transmitted by an optical fiber 2-1 and the output from the photodetector 4 detecting the light of the wavelength lambda2 are compared, by which the temp. of the crystal 3-1 is known. The temps. of the semiconductor crystals 3-2, 3-3-3-n are similarly known.

Description

Detailed Description of the Invention This invention relates to the energy band gap (e) of semiconductor crystals.
The present invention relates to a temperature measuring device that measures temperature by utilizing the characteristic that energy band gap (energy band gap) changes depending on temperature.

In conventional devices of this type, one measurement point requires a light emitting source,
Since one photoreceiver was required for each, there was a drawback that it was expensive for multi-point measurements.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional devices, and an object of the present invention is to provide a device that can measure temperatures at multiple points by having one light emitting source and one light receiver. It is.

Hereinafter, the present invention will be described in detail with reference to the drawings. The drawing is a configuration diagram showing an embodiment of the present invention, and in the figure (
1) is the light source, (2) , (2-1) , '(2-
2) ... is an optical fiber, (3-1), (3-2)
, . . . (3-n) are semiconductor crystals, respectively. If there are n points at which temperature should be measured, n semiconductor crystals are prepared and placed at each temperature measurement point, but the order of placement is as shown in the figure (3-1), (3 -2
) , ... (3-n), the wavelength λ1 . of the energy band gap of each semiconductor crystal. λ2. ...λ. They are arranged so that λ1<λ2<...λ. (4) is a light receiver, and (5) is a signal processor. Light emitting source (1), each semiconductor crystal (3-1), (3-2)
,...(3-2), and receiver and optical fiber (2)
, (2-1), and (2-2) (that is, inputting light into an optical fiber or inputting light emitted from an optical fiber) is not shown in the drawing. However, it is assumed that a conventionally known device is provided. The light emitting source (1)→semiconductor crystal (3-1)→(,3-2)→・
−・→(3-n)→Photodetectors (4) are connected in cascade, and 75) semiconductor crystals (3-1), (3-2), ・−・(3
- (n-1)) is transmitted through the optical fiber (2-
1), (2-2), . . . are guided to the light receiver (4).

The light emitting source (1) is λ1. λ2. ...λ. , λn+1 (
(n+1) types of wavelengths are repeatedly sent out in a time-division manner and periodically. However, λ. +1〉λ. and λ1.
λ2゜...λ. The wavelength indicated by etc. does not have to exactly match the wavelength of the energy gap described above as long as it approximates it.

In the semiconductor crystal (3-1), λ2. λ3...λ9. λ1
Light with a wavelength of +l is transmitted without attenuation, and λ1
Only light with a wavelength of 2 is attenuated depending on the temperature of the semiconductor crystal (3-1). In the semiconductor crystal (3-2), λ3.・−
・λ. .

Light with a wavelength of λ11+1 is transmitted without being attenuated, and light with a wavelength of λ2 is attenuated depending on the temperature of the semiconductor crystal (3-2). So λ. Light with a wavelength of λ is transmitted without attenuation, and λ. Light with a wavelength of
) can be obtained with temperature-dependent damping.

In addition, the time-sharing information for changing the wavelength of the emitted light in the light emitting source (1) is input to the signal processor (5), so the signal processor (5) determines which wavelength of light is output from the light receiver (5). It is possible to distinguish whether the signal represents the strength of the signal.

Comparing the output of the optical receiver (4) for the wavelength λ1 transmitted by the optical fiber (2-1) and the output of the optical receiver (4) for the wavelength λ2, the semiconductor crystal (
3-1) Calculate the demerit of light with wavelength λ1 in
Therefore, the temperature of the semiconductor crystal (3-1) can be known. Similarly, the output of the optical receiver (4) for the wavelength of λ2 transmitted by the optical fiber (2-2) and the output of the optical receiver (4) for the wavelength of λ3 are compared, and the output of the optical receiver (4) for the wavelength of λ3 is compared.
-2) is transmitted from the semiconductor crystal (3-n) through the optical fiber (2). receiver (4
) and the output of the photoreceiver (4) for the wavelength λn+□, the temperature of the semiconductor crystal (3-n) can be determined.

As described above, according to the present invention, temperatures can be measured at multiple points with a simple and inexpensive device. Additionally, since optical fibers are used, the temperature of high-potential parts, areas with a lot of conduction noise, and areas with a risk of explosion can be measured safely and without interference from noise. .

[Brief explanation of the drawing]

The drawing is a configuration diagram showing an embodiment of the present invention. (1)...Light emission source, (2), (2-1), (
2-2)...Optical fiber, (3-1), (3-2
) ,...(3-n)...semiconductor crystal, (4)...
- Light receiver, (5)...signal processor. Agent Shin Kuzuno −

Claims (1)

[Claims] In a temperature measuring device that measures temperature using the property that the energy bandgap of a semiconductor crystal changes depending on temperature, when there are n points (n is any positive integer) at which temperature should be measured, n Prepare semiconductor crystals each having a different energy band gap, and place the n semiconductor crystals one by one at the n temperature measurement points in order of the wavelength of the energy band gap, and light from the light emitting source. means for optically connecting a fiber to a semiconductor crystal having the shortest energy bandgap wavelength, optically cascading n semiconductor crystals arranged in the following order by means of an optical fiber; output light,
means for guiding the output light from the other semiconductor crystals to the light receiver through optical fibers, and guiding a portion of the output light from the other semiconductor crystals to the light receiver through separate optical fibers; and an energy band gap between the n semiconductor crystals from the light emitting source. Sequentially generates light with a wavelength having an energy approximate to , for each wavelength, and then generates light with a longer wavelength than the last generated light,
means for repeating the light of (n+1) wavelengths generated in this manner in a time-division manner and sending it out to an optical fiber connected to the light emitting source; The intensity of each input light is measured in a time-division manner, and the intensity of the light at the wavelength of the energy band gap,
A temperature measuring device comprising means for calculating the temperature of the semiconductor crystal from a comparison of the intensities of the light having a longer wavelength with an energy bandgap that is one step lower than that of the light.