Research On Improving The Accuracy Of Seismic Detector Distortion Measurement

Geophone is an important part of mineral exploration,and its performance directly determines the result of mineral exploration.Therefore,high performance geophone is particularly important in mineral exploration.At present,many kinds of geophone have been developed by domestic and foreign enterprises.First,the distortion of large damping geophone and small damping geophone can not be measured by a tester,and second,the precision of measuring the distortion parameter of geophone is not accurate enough.Therefore,it is necessary to develop a high precision detector distortion tester to screen out excellent geophone.For Therefore,this paper carries on the following research work and has obtained the stage result.First,complete the establishment of mathematical model,analyze the test methods to improve the accuracy of the seismic geophone distortion test,explore the feasibility of improving the accuracy of geophone distortion testing program analysis.The differential technique is used to design the control circuit system for measuring the distortion of geophone.Secondly,the core peripheral circuit of the detector distortion testing instrument is designed,including the excitation source module,the data acquisition module,the serial communication interface circuit and the independent power supply module.The signal excitation source of the tester is 24-bit D/A conversion chip DAC1282,.The chip can produce low distortion sinusoidal signal with variable amplitude and frequency.The data acquisition circuit uses 32 bit A/D conversion chip ADS 1282 for data acquisition,and uses serial port to communicate with the host computer.Third,complete the design and debugging of upper computer and lower computer program.The upper computer is mainly the algorithm of distortion and the VS2012 user display interface,and the software of the lower computer is mainly the single chip microcomputer driver program,the excitation program,the data sampling program and the serial port communication program between the lower computer and the host computer.Fourthly,the distortion of seismic geophone is measured and the results are analyzed.The distortion parameters of underdamped geophone and overdamped geophone are tested,and the precision of testing the distortion of the geophone can reach 1/10000.In this paper,the differential technique is used to test the distortion of the moving coil seismic geophone,and high performance devices,such as DAC1282,ADS1282,etc.,are used to verify that the full differential technique can further improve the accuracy of the distortion test.The operation interface adopts the full Chinese menu,which is suitable for different levels of testers to operate,and can quickly set up the distortion test for the under-damped or over-damped geophone,which is of great significance for improving the acquisition quality of seismic data in the field.