The Study Of New Type Seismic Geophone Used In Geophysical Explore

As one kind of sensors, geophone is widespread used on oil, geology detection and engineering survey. With the demand of oil, gas and other mineral material increasing, traditional geophones are not content to the requirement of the seismic detection. Some companies, such as SENCEL of FRANCE , OYO of JAPAN and I/O of AMERICA, are devoted to work over and develop new type geophones. Some achievements attained by scientific department.This work was supported by the National Natural Science Foundation of China under Grant No．40274046.Two new type geophones theory is presented in this paper. Because it is made by glass, grating has many virtues, such as erosion resistant, electromagnetism resistant and it can work in a very high temperature environment.One is based on the theory of moiré fringe. In this vibration measurement system, simply optical structure is adopted. The moiré fringe used in the system is immune to the transverse wave. Movement equation of this measurement system is presented in chapter 3, and the damping system is designed.The other is based on the theory of frequency shift which is brought by Doppler effect. In this measurement system, two diffraction gratings are used. In chapter 5, the measuring principle is analyzed theoretically. The system provide perfect signals with high signal-to-noise.