A Study of Polarization Capacity over a Wide Frequency Band

Abstract

The polarization capacity of platinum electrodes in sulphuric acid and also of gold electrodes in sulphuric acid has been studied from 200 to 200,000 cycles per second. An alternating current bridge was used to make the measurements in the audible range and a bridge with heterodyne detector for the higher frequencies. If the relation connecting capacity and frequency is put in the form $C=\frac{C_0}{f^P}$ where $C_0$ and $P$ are constants then at the lower frequencies $P$ is nearly equal to.3 while at the higher frequencies it approaches.5. At the same time, the phase angle of the capacity shifts from about 20 to about 40 degrees. Voltage measurements made to determine the limiting value of the initial capacity show that it is of the same order of magnitude for alternating current as for direct charge. When two harmonic alternating currents of differing frequencies are simultaneously impressed on a cell, the polarization capacity measured by means of either one is independent of the presence of the other.