Simulation And Detection Circuit Design Of Electrochemical Seismometer

Seismometer is a kind of instrument for acquiring seismic data.With the emergence of high-precision seismic exploration and high-resolution seismic data acquisition,a new type of seismometer with new detection principle and higher performance has entered the field of seismic exploration,which is more suitable for the needs of seismic exploration.As a new type of seismometer,the electrochemical seismometer is based on electrochemical principle,which uses liquid as inertial mass.It has attracted much attention because of its good low frequency characteristicslarge,low noise,strong shock resistance and high sensitivity.At present,the electrochemical seismometer manufactured successfully in our laboratory is not widely used because of its poor frequency characteristics,complex fabrication process and high cost.In order to further improve the performance of electrochemical seismograph and expand its application field,we studied and designed the sensitive element and detection circuit of electrochemical seismometer in this paper.Firstly,we established the multi-physical field model of seismometer and the simulation model of sensitive element in COMSOL simulation software according to the working principle of electrochemical seismometer.The influence of the structural parameters of the sensitive element on the sensitivity and thermal noise of the electrochemical seismograph is simulated and analyzed,and the more ideal structural parameters of the sensitive element are obtained.Secondly,in order to detect vibration signal more accurately,a digital signal processing system is designed to improve the frequency characteristics of electrochemical seismometer.The digital signal processing system uses ST company's chip STM32F373 CC as the main control chip.Main work of designing system includes draw of schematic diagram and compilation of algorithm.We needed to design circuits and PCB in order to complete pre-amplification,signal processing and supply power for the system.What's more,we finished the compilation of MCU and PC program.Also,the calculation formula of digital filter coefficient is given according to the function description of the signal processing arithmetic.Finally,we need to test and verify the digital signal processing system.The system is connected with the analog signal processing circuit of the electrochemical seismometer,and the seismometer before and after processing is calibrated by the shaking table device in our laboratory.According to the calibration experiment results,it can be seen that the frequency response curves of the electrochemical seismometer after the digital processing circuits is more flat.Therefore,the detection circuit designed in this paper can improve the frequency characteristics of the electrochemical seismometer and lay a foundation for the development of the application field of electrochemical seismometer.