Temperature detecting system and method based on sapphire fiber grating sensor

Abstract

The invention provides a temperature detecting system and method based on a sapphire fiber grating sensor. The system of the invention comprises a broadband light source, a sapphire fiber grating sensor, a fiber circulator, a F-P filter, a photoelectric conversion module, an A / D conversion module, an acquisition control module, a D / A conversion module and a computer module. The method of the invention comprises the following steps: detecting reflected light wavelengths of the sapphire fiber grating sensor at each temperature by using a spectrometer; obtaining a fitting model of the reflected light wavelengths and the temperatures by a least square method; placing the sapphire fiber grating sensor on a target to be tested, and outputting a beam emitted by the broadband light source to the F-P filter through the fiber circulator; periodically changing the length of a F-P cavity according to a driving voltage digital signal sent by the acquisition control module; obtaining and storing themaximum value of the voltage of transmitted light of the F-P filter in the acquisition control module; and obtaining the temperature information according to the fitting model of the reflected lightwavelengths and the temperatures, and displaying the result.

Description

technical field [0001] The invention relates to the field of optical fiber sensing, in particular to a temperature detection system and method based on a sapphire fiber grating sensor. Background technique [0002] With the improvement of the range and flight speed of the aircraft, the thrust and thrust-to-weight ratio of the aircraft are also increasing, which leads to a great increase in the inlet temperature and combustion chamber temperature of the aero-engine. At present, the inlet temperature of the advanced aero-engine turbine has reached above 1650°C , with the continuous development of the aviation industry, the operating temperature of more advanced aero-engines will be further increased in the future, making the monitoring technology of aero-engine temperature an urgent problem to be solved. [0003] At present, the common high-temperature measurement methods include non-contact measurement and contact measurement. Non-contact measurement is limited to the tempera...

AI Technical Summary

Problems solved by technology

The existing technology cannot fully meet the actual needs, and it is urgent to develop a new measurement technology with high precision, high reliability and adaptability to various environments.

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