Circuit Design And Test Research Of Four Component Borehole Strain Gauge

Four component borehole strain meter is continuous measurement of crustal stress and strain of the instrument,the state change of crustal stress is caused by deformation and failure cause surface folds and faults and earthquakes,occurrence and variation of ground stress effect is closely related to a variety of geological disasters in the surface of the crust.So the research of four component borehole strain has great significance for observing and recording the surface stress changes,and provides important data for continuous measurement of borehole strain for earth elastic research,provide strong evidence for earthquake prediction.The rationality of the circuit design determines the accuracy of the instrument measurement data,whether the circuit design is reasonable and practical.In this paper,the circuit design of the four component borehole strain gauge is discussed,and the linearity and sensitivity of the instrument are tested.This paper consists of the following chapters:The first chapter mainly elaborates the research background of the strain gauge,the domestic and foreign development status and development trend,some strain gauges exist,and put forward the design based on the existing strain gauge on the improvement and the problems to be solved.The second chapter mainly elaborates the working principle of capacitive strain gauge,and the differential capacitive sensor has the advantages and practical problems,and expounds the strain gauge transducer by strata stress when the main determination of stress azimuth.In the third chapter,the circuit design module of capacitive borehole strain gauge is introduced,for each module is described in the theory that the RC oscillation circuit faults,and excitation of the sensor signal of the circuit is improved,the development of the crystal high amplitude and high frequency stabilization design of oscillating signal model.Describes the design of the circuit module of the amplifying circuit,synchronous detection circuit,filter circuit,the synchronous detection circuit is improved,and the advantages of the circuit module is before the circuit is analyzed.Finally,the comparative analysis of the measured circuit before and after the improvement is completedThe fourth chapter mainly expounds the principle of the whole machine testing,including linearity,resolution,sensitivity and frequency response range test program,and analyzes the test data,and draws the test conclusion.In the fifth chapter,the error analysis is introduced,and the error of the sensitivity test is analyzed.The rationality of the test equipment is proved by comparing the test result with the actual standard sensitivity.Finally,the whole paper is summarized,and the shortcomings are pointed out,and the lightning protection design of the existing strain gauge is discussed.