High-precision distributed optical fiber temperature sensing system

Abstract

The invention discloses a high-precision distributed optical fiber temperature sensing system. According to the system, different sampling rates are set for a data acquisition unit according to the characteristic of different wavelengths of stokes and anti-stokes to ensure that each pair of acquired stokes and anti-stokes data corresponds to a position on an optical fiber; the influence of the different wavelengths of the stokes and the anti-stokes on spatial resolution, positioning precision and temperature precision is eliminated fundamentally; the three key indexes of the system are improved; and the application scope of the distributed optical fiber temperature sensing system is expanded.

Description

technical field [0001] The invention relates to a high-precision distributed optical fiber temperature sensing system, in particular to a high-precision distributed optical fiber temperature sensing system based on the Raman dispersion principle. Background technique [0002] The distributed optical fiber temperature sensing system is composed of two parts: the host computer and the optical fiber. It can detect the temperature information of all positions along the optical fiber laying line, and realize the monitoring of long-distance oil and gas pipelines and the full-range temperature monitoring of ultra-long-distance power cables. With the characteristics of safety and long life, it can be widely used in power systems, cable tunnel fire detection applications, oil pipeline or storage tank leakage monitoring, etc. To achieve the purpose of prevention in advance, to ensure the safety of national property and people's lives. [0003] The working principle of the existing di...

AI Technical Summary

Problems solved by technology

However, due to the large wavelength difference between the Stokes light and the anti-Stokes light, the refractive index in the optical fiber is different, and the propagation speed of the two in the optical fiber is different, the data collected by the data acquisition unit is the data at the same time, while data not in the same location

Therefore, the time-domain reflection curves of Stokes light and anti-Stokes light will appear "step difference", which will reduce the spatial resolution, positioning accuracy and temperature measurement accuracy of the system, and even cause temperature calculation errors

[0004] The patent "A Distributed Optical Fiber Raman Temperature Sensor with Dispersion and Loss Spectrum Self-calibration" (Application No.: 201020157461.7) proposes to use dual light sources to realize the self-calibration of dispersion and loss spectra, but it needs to add a light source, accounting for 1 of the main cost / 3 or so

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