THE INFLUENCE OF THE INDUCTION OF MULTI-TURN COILS FOR TEM ON THE DETECTION OF BURIED OBJECTS IN UNDERGROUND MINES

Due to the self-transition of the loop,the early signal of TEM suffers great distortion.In order to study characteristics of the early signal with TEM,the authors formulated self-induction formulae for single coil and multi-turn coils,deduced theoretical expressions for the amplitude of the loop self-induction signal,and gave the induction of single coil and multi-axial coils.The response curve of buried object affected by the coils and the length of loop's change are also studied.The results obtained lay a foundation for further studies of the additional effect of the early field and can serve as reference data for further researches.