A novel transient electromagnetic measuring system

Abstract

Transient electromagnetic measuring system, a kind of geophysics detecting devices, still have some technological problems unsolved in high current steep pulse transmitting, high precision synchronous control, large dynamic range signal gathering, etc., This paper proposes a novel transient electromagnetic measuring system(WTEM) with some technological improvements, including: (1) applying PocketPC and Bluetooth wireless technology in receivers to improve the system performance and reduces the receivers scale; (2) constructing a steep pulse transmitting circuit to output high current pulse with high linearity falling edge, short shut-off time and fast rising edge, finally improving the surficial resolving power; (3) proposing a GPS synchronous controller with high synchronous precision, in which TCXO working with GPS corporately, recovering the short-time invalidation of GPS module. In the project of detecting the oil pipeline corrosion, indoor and field tests have been done to WTEM system. The results indicate that WTEM possesses fine performances, short withdrawing time from saturation status, high synchronous precision and short turn-off time of transmitting current, etc..