【摘要】 由于线圈的自感耦合作用 ,使瞬变电磁早期时间道信号严重失真。为研究瞬变电磁早期信号的特性 ,分析了瞬变电磁线圈等效回路的暂态过程 ,得出线圈自感信号振幅的理论表达式 ,计算了不同大小线圈的自感信号的幅值和衰减时间范围 ,得出了瞬变电磁测深法对地探测时存在一个不可分辨的"盲深度"。作者提出了不同线框大小和不同介质电阻率情况下 ,估算瞬变电磁能探测的最小深度的方法并给出了估算结果。所研究成果对进一步研究瞬变电磁早期场的附加效应打下了基础。同时得出的瞬变电磁最小探测深度的结论对野外生产工作具有指导意义更多还原

【Abstract】 Because of the self-transition of the loop the early signal of transient electromagnetic method (TEM) is greatly abnormal. In order to study the characteristics of the early signal with TEM the transient process of transient electromagnetic loop is discussed and the theoretical equation for the self-transient signal is given.The amplitude and the decay time scope of different loop are calculated. It is indicated that a lind depth exists with TEM. The minimum detecting depth by the said method is presented for the different media and the loop sizes. The calculation method and the results are also given, which lay a foundation for the further study on the additional effect of the early field and for the guide to the field inspection.更多还原