Whole optical fiber colorimetric temperature measuring method based on optical fiber bragg grating

Abstract

The invention discloses a whole optical fiber colorimetric temperature measuring method based on optical fiber bragg grating. Optical fiber bragg gratings FBG1 and FBG2 are used as filters; a spectrum received by a sensing head reaches to the first to second ports of a three-terminal circulator (10) to be coupled to an incidence end of the FBG1; the reflection optical wave of the FBG1 is transmitted to a first photoelectric detector (12) through second to third ports of the three-terminal circulator (10) for photoelectric conversion; similarly, a transmitted spectrum of the FBG1 is transmitted to the incidence terminal of the FBG2 through the first to second ports of the three-terminal circulator (10); the reflection optical wave generated by the FBG2 reaches to a second photoelectric detector (13) through the second to third ports of the three-terminal circulator (11) so as to accomplish the photoelectric conversion to obtain two electric signals of different wavelengths; and the two electric signals of different wave lengths are processed to obtain the tested temperature subsequently. The filter of the system adopts the optical fiber bragg grating to replace an existing light filtering sheet; and the method has the advantages of optical fiber coupling easiness and installation convenience.

Description

technical field [0001] The invention relates to a radiation temperature testing technology of a temperature field, in particular to a non-contact colorimetric temperature measuring technology and a filtering technology thereof. The present invention uses fiber Bragg gratings instead of traditional filters to realize narrow-band filtering of two different wavelengths, and transmits light waves to photoelectric detectors by optical fiber three-terminal circulators, which has the advantages of full optical fiber transmission, convenient installation and debugging, and easy integration; The method has a simple optical system, can be integrated with optical fibers, and is suitable for measurement in harsh environments. Background technique [0002] Temperature testing methods can be divided into contact measurement and non-contact measurement methods. In a relatively harsh environment, contact measurement is easy to damage the sensor and destroy the measured temperature field. T...

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Problems solved by technology

[0005] However, there are still some factors that are not conducive to the application of the previous colorimetric temperature measurement system.

For example, optical lenses are used to collect radiation from high-temperature objects in the past. These optical lenses are composed of different optical lenses. The assembly and debugging are more complicated and the volume is larger; in order to obtain the required filters with two different center wavelengths, special films are used High-performance filters made of high-performance filters, which increase the cost

[0006] In the previous colorimetric temperature measurement method, most improvements were made from the photoelectric demodulation part, while the improvement from the optical path was less

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