Distributed optical fiber sensing system for measuring temperature, strain and vibration simultaneously

Abstract

The invention discloses a distributed optical fiber sensing system for measuring temperature, strain and vibration simultaneously. Based on an Optical Time Domain Reflectometry (ODTR) multiplexing technology, optical time-division multiplexing unequal-width dipulse serves as detection light, coherent detection technologies of Brillouin scattering signals and Rayleigh scattering signals are merged,and a set of distributed optical fiber sensing system which can conduct single-ended measuring on the temperature, strain and vibration is achieved; meanwhile, the measuring range of the vibration frequency can reach the MHz level, and the problems are solved that a traditional ODTR system can only measure the temperature strain or the static strain while cannot timely respond to the dynamic change, or it is hard to measure the temperature strain and the static strain simultaneously, or the measurable range of the vibration frequency is limited by the length of sensing optical fiber. The distributed optical fiber sensing system can conduct single-ended measuring, and is simple in structure, easy to implement, and good in application prospect.

Description

technical field [0001] The invention relates to a distributed optical fiber sensing system, in particular to a technique based on optical time-division multiplexing of unequal-width double pulses to obtain backward Brillouin scattered light signals and backward Rayleigh scattered light signals in optical fibers to realize Time-division multi-optical time domain reflectometry (OTDR) distributed optical fiber sensing system for simultaneous measurement of multiple parameters of temperature, strain and vibration. Background technique [0002] With the continuous construction and use of large-scale infrastructure, online safety and health monitoring, fault prevention and timely detection of large-scale bridge civil structures, oil pipelines, highways, railways and other facilities have also received more and more attention. However, due to the large span of such basic engineering facilities, the complex structure and environment, traditional monitoring methods (such as the use o...

AI Technical Summary

Problems solved by technology

Although this technology has been applied in distributed vibration sensors, the existing distributed optical fiber sensing systems used to measure vibration are mostly double-ended measurement or loop structures, and once there is a break in the optical fiber, the entire system will fail

At the same time, its detectable frequency range is limited by the length of the sensing fiber

[0006] At present, there are no relevant reports on the research of distributed optical fiber sensing systems that can simultaneously detect strain, temperature, and high-frequency vibrations, but the demand for distributed optical fiber sensing systems that can simultaneously detect strain, temperature, and high-frequency vibrations is increasing day by day

Images