Electrical prospecting with non-sinusoidal alternating currents
Samuel Stewart West · Geophysics · 1938
Abstract A method of electrical prospecting using alternating current of rectangular or other non-sinusoidal waveform is described. The changes in waveform caused by anomalous subsurface structure are determined by a null method in which the detected electromotive force is balanced against an electromotive force produced by passing the output of a standard oscillator through an adjustable network. This process of measurement (applicable also to the transient method) makes possible a useful representation of the data in terms of two-dimensional contours.