F-P cavity type high-temperature large-strain optical fiber sensor

Abstract

The invention belongs to the technical field of sensors, and discloses an F-P cavity type high-temperature large-strain optical fiber sensor, which comprises a transmission optical fiber, a reflectingmirror, an inner sleeve, an outer sleeve, a clamp for fixing the outer sleeve and a sealing structure; the transmission optical fiber can ensure the coaxiality through mutual embedding of the two sets of sleeve devices, and a Fabry-Perot cavity, namely an F-P cavity, is formed between the end face of the optical fiber and the reflecting mirror. The cavity length of the F-P cavity can be changed due to deformation of a measured material, so that the change of a reflection spectrum is caused, and the strain of the material is monitored by analyzing the variation of the spectrum. The F-P cavitytype high-temperature large-strain optical fiber sensor is based on a high-temperature strain gauge of a Fabry-Perot interference principle, and can measure material deformation of tens of thousands to hundreds of thousands of micro-strain levels at high temperature. The optical fiber sensor can realize measurement of large strain at high temperature and simultaneous measurement of temperature andstrain parameters, and is high in measurement precision, high in stability and easy to popularize.

Description

technical field [0001] The invention belongs to the technical field of sensors, in particular to an F-P cavity type high-temperature and large-strain optical fiber sensor. Background technique [0002] As the application range of optical fiber continues to expand, people's requirements for its measurement performance are also getting higher and higher. In actual engineering, we sometimes need fiber optic sensors to achieve strain measurement at high temperatures. For example, in the aerospace field, aircraft must withstand high temperature, high pressure, corrosion and other harsh operating environments. How to use strain sensors to detect the stress of aircraft structures in high temperature environments Change is an urgent problem to be solved. Due to the influence of high temperature environment, optical fiber cannot accurately measure material strain, which greatly reduces the reliability of optical fiber strain sensor. In order to solve this problem, scholars at home ...

AI Technical Summary

Problems solved by technology

This type of optical fiber sensor is limited by the ultimate strain of the optical fiber, and its measurement range is small, so it cannot accurately measure the strain of the substrate with large deformation

Most high-temperature strain sensors, high-temperature-resistant pressure sensors and other optical fiber sensors are only for single-parameter measurement, and there are relatively few technical researches on temperature and strain dual-parameter measurement, and there are problems such as low measurement accuracy and low reliability.

[0004] To sum up, the current high-temperature strain sensors based on optical fibers have problems such as complex structure, low precision, and low reliability.

Most fiber optic sensors are affected by the measuring range and encounter difficulties in measuring the strain of large deformation substrates

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