Self-calibration detection device and temperature demodulation method oriented to optical fiber Raman temperature sensing system

Abstract

The invention discloses a self-calibration detection device and a temperature demodulation method oriented to an optical fiber Raman temperature sensing system. The self-calibration detection device comprises an optical fiber Raman thermodetector, a constant temperature tank, a multi-mode sensing fiber and a multi-mode reflector, wherein the optical fiber Raman thermodetector comprises a pulse laser; the output end of the pulse laser is connected with the input end of WDM (Wavelength Division Multiplex); two output ends of the WDM are respectively connected with the input ends of a first APD (Angular Position Digitizer) and a second APD; the output end of the first APD is connected with the input end of a first LNA (Low Noise Amplifier); the output end of the second APD is connected with the input end of the second LNA; the output end of the first LNA and the output end of the second LNA are connected with the input end of a data acquisition card; the output end of the data acquisitioncard is connected with the input end of a computer. According to the self-calibration detection device, the problems of low temperature measuring accuracy, lower temperature measurement stability andlow temperature measurement efficiency caused by a temperature demodulation method in an existing distributed optical fiber Raman temperature measuring system can be solved.

Description

technical field [0001] The invention relates to the field of temperature demodulation in a distributed optical fiber sensing system, in particular to a self-calibrating temperature detection device and a temperature demodulation method for an optical fiber Raman sensing system. Background technique [0002] Distributed optical fiber sensing technology uses the optical fiber itself as both a signal transmission medium and a sensing unit to obtain the distribution of external physical quantities of the entire optical fiber link. The distributed optical fiber sensing system has high measurement accuracy, long sensing distance, and good reliability. It has been widely used in the health monitoring of infrastructure such as smart grids. [0003] In the distributed optical fiber Raman temperature measurement system, the commonly used temperature demodulation method is to use Stokes backscattered light as the reference channel, use anti-Stokes backscattered light as the signal chan...

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Problems solved by technology

[0005] In order to solve the problem that the temperature measurement performance of the existing distributed optical fiber Raman sensing system drops sharply due to phenomena such as optical fiber dispersion, APD temperature drift, and optical fiber sudden bending, the present invention proposes a distributed optical fiber Raman temperature sensor System self-calibration detection device and temperature demodulation method

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