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

Abstract

The invention discloses a distributed optical fiber sensing system capable of simultaneously measuring a temperature, a strain and vibration. The system comprises a frequency sweeping laser, an optical coupler, an optical fiber delay line, a balance optical detector, a pulse laser, an optical isolator, an optical fiber circulator, a band-pass filter, a wavelength division multiplexer, a single-channel photoelectric detector, a double-channel photoelectric detector, a data acquisition card and a single-mode sensing optical fiber. In the system, a temperature sensing unit and a vibration sensingunit share a pulse laser, a frequency sweeping laser provides light sources for a strain sensing unit, and the two light sources are connected through an optical coupler; and the wavelength divisionmultiplexer is connected with the optical coupler and the sensing optical fiber. According to the sensing system, comprehensiveness of the sensing system to environment monitoring is improved, and thesensing system has a higher practical value.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, in particular to a distributed optical fiber sensing system for simultaneous measurement of temperature, strain and vibration. Background technique [0002] The key technologies of the existing independent distributed temperature measurement system, distributed strain measurement system, and distributed vibration measurement system have become mature and have industrial-level applications, and the performance parameters of the system (spatial resolution, measurement accuracy, etc.) constantly breaking through. However, due to the limitation of backscattered signal power, most of the sensing fibers of these independent distributed measurement systems are multimode fibers, and there are relatively few research materials on distributed sensing systems based on single-mode fibers. At most, the sensing system only realizes the simultaneous measurement of two physical quantities (colline...

AI Technical Summary

Problems solved by technology

However, due to the limitation of backscattered signal power, most of the sensing fibers of these independent distributed measurement systems are multimode fibers, and there are relatively few research materials on distributed sensing systems based on single-mode fibers. At most, the sensing system only realizes the simultaneous measurement of two physical quantities (collinear sensing of temperature and strain or collinear sensing of temperature and vibration) on the same optical fiber, and does not realize the simultaneous measurement of three physical quantities of optical fiber temperature, strain, and vibration on one optical fiber. measurement system

The above two points have restricted the in-depth application of distributed optical fiber sensing technology to a certain extent.

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