Long-distance large-range optical fiber strain generating device and generating method

Abstract

The invention provides a long-distance large-range optical fiber strain generating device. The device comprises a dual-frequency laser interference length measuring device light source, a detector and a full reflection device, wherein the dual-frequency laser interference length measuring device light source and the detector are fixed to a left clamp carrier platform, the full reflection device is fixed to a right clamp carrier platform, and the dual-frequency laser interference length measuring device light source, the detector and the full reflection device form a distance measuring laser light path which is used for measuring the optical fiber distance and the optical fiber strain value. By means of the scheme, a sliding rail is moved for a long distance so that distance measurement is changed into displacement measurement. The original length and the stretching length of an optical fiber strain generation portion can be precisely measured through the high-precision long-distance dual-frequency laser length measuring device. Strain is generated precisely through an electric control displacement platform. Strain generation precision is improved and the optical fiber length is increased, and the defects that an existing strain generating device is low in precision and short in optical fiber operation distance.

Description

technical field [0001] The invention belongs to the field of optical fiber strain generating devices, and in particular relates to a long-distance and large-range optical fiber strain generating device and a generating method. Background technique [0002] Optical fiber sensors are more and more used in engineering because they are not affected by electromagnetism, can work in harsh environments for a long time, are intrinsically safe, and have high sensitivity. Especially, optical fiber strain sensors are one of the main research directions of optical fiber sensors. It is widely used in construction, security, dams, industry and other fields. During the development, production and construction and acceptance of the optical fiber distributed strain tester (abbreviated as BOTDR), the strain generation device is required to generate a certain amount of strain for strain calibration of the optical fiber distributed strain tester. And carry out strain calibration on the optical...

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Problems solved by technology

[0004] However, in actual use, due to the structural limitations of the constant-strength beam, it is difficult to strain the optical fiber with a length of more than 2m, and the strain range it produces is relatively small (about 0-2000με). Strain is generated, and the strained part of the optical fiber needs to be all pasted on the equal-strength beam, so the strain generated by the equal-strength beam cannot be fully transmitted to the optical fiber. The accuracy of strain generation is low and the error is large; while using the method of hanging heavy objects to generate strain, although it can generate strain on longer optical fibers, it is difficult to reach 20m, and the range of strain generation is also small, and the method of hanging heavy objects cannot To obtain the strain value directly, it needs to be converted according to the mass of the suspended weight and the elastic modulus parameter of the optical fiber, and the elastic modulus of the optical fiber is related to the material and doping of the optical fiber. The real elastic modulus is difficult to obtain and can only be obtained by theoretical Therefore, there is a large error between the calculated strain value and the actual strain value; the three-dimensional strain simulation platform has a complex structure, and the strain generation length is short, and the strain generation accuracy is also low

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