Closed ring feedback control distribution type optical fiber temperature sensing system at non-constant temperature

Abstract

The invention is a closed ring feedback control distribution type optical fiber temperature sensing system at non-constant temperature, mainly comprising a laser, an output end of which is connected with a light-way divider; one section of a start portion of measuring optical fiber output by the light-way divider is selected as reference optical fiber and temperature in periphery is measured by platinum resistor; the light-way divider divides retrodiffusion lights into Stocks and antiStocks lights which are transmitted to an APD group composed of two APDs in an APD receiving and control module provided with a platinum resistor which affects multiplying parameter of factor of APD optical electrical conversion signal; temperature of work environment of APD is transmitted to the control unit which adjusts voltage of the APD via a high voltage plate to maintain the multiplying parameter of APD optical electrical conversion signal invariable to receive optical electrical signal stably; the other by platinum resistor measures environmental temperature of position where the optical fiber is. After AD conversion and algorithm process, the optical fiber sensing temperature can be calibrated.

Description

technical field [0001] The invention relates to the technical field of distributed optical fiber temperature sensing, in particular to a technical proposal for a closed-loop feedback control distributed optical fiber temperature sensing system under non-constant temperature. Background technique [0002] The distributed optical fiber temperature sensor uses optical fiber temperature sensing to determine the distribution of the continuous space temperature field. Compared with the traditional temperature sensor, the sensing element of the distributed optical fiber temperature measurement system uses optical fiber, which has electrical insulation, corrosion resistance, Inherent characteristics and intrinsic safety such as wide signal transmission bandwidth, low loss of long-distance information transmission, etc., for temperature testing in harsh environments such as strong electromagnetic fields, high voltage and high current, flammable and explosive, complex geometric spaces ...

AI Technical Summary

Problems solved by technology

[0004] The invention provides a solution for closed-loop feedback control distributed optical fiber temperature sensing system under non-constant temperature. By improving the internal structure of the system, the temperature-affected light intensity of lasers and avalanche photoelectric receiving diodes (APD) is improved. The problem of strong attenuation and multiplication coefficient reduction overcomes the shortcomings and deficiencies of the existing optical fiber temperature sensing system

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