Push-pull optical fiber displacement sensor with compliant cylinder structure and optical fiber strain gauge

Abstract

The invention provides a push-pull optical fiber displacement sensor with a compliant cylinder structure and an optical fiber strain gauge. A first optical fiber displacement sensor fixed on a first bed rock is connected with the head end of a measure baseline bar; a second optical fiber displacement sensor fixed on a second bed rock is connected with the tail end of the measure baseline bar; the first optical fiber displacement sensor and the second optical fiber displacement sensor are connected with a measurement control and signal recording and processing system through signal connecting wires; a laser output a light source passes through an isolator, and then the energy is averaged into two parts by a first coupler; a half of light energy is injected into the first optical fiber displacement sensor, and the other half of light energy is injected into the second optical fiber displacement sensor. The push-pull optical fiber displacement sensor can be widely applied to the field of geophysical researches of observing crustal strain and solid tide, obtaining earthquake precursor information and the like.

Description

technical field [0001] The invention relates to an optical fiber sensing and measuring device. Specifically, it is a kind of optical fiber displacement sensor and strain gauge used for geophysical research, observing crustal strain and solid tide, and obtaining earthquake precursor information. Background technique [0002] The strain gauge is an instrument that precisely measures the relative change of the distance between two points in the crustal rock mass. It has important applications in the fields of observing crustal strain and solid tides, as well as studying the process of earthquake breeding and obtaining earthquake precursors. [0003] Since the American seismologist H. Benioff developed the first valuable quartz extensometer in 1935, the United States, Britain, the former Soviet Union, Japan, Belgium, Germany and other countries have successively developed high-sensitivity extensometers. instrument. The sensitivity of the instrument is generally 10 -8 Above, s...

AI Technical Summary

Problems solved by technology

[0008] Displacement sensors currently invented in strain gauges mainly use eddy current displacement sensors, differential transformer displacement sensors, or capacitive displacement sensors, among which the best displacement resolution of the first two is about 1 nanometer; The force can reach 0.01 nanometers, but the disadvantages are that the parasitic capacitance and distributed capacitance have a great influence on the sensitivity and measurement accuracy, the output is non-linear, the connection circuit is complicated, and it is subject to humidity and electromagnetic interference. It is not very suitable for the reliability of the strain gauge. , high stability requirements, long-term work and other practical occasions

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