the current that results from the applied direct potential consists of two parts
that in leakage paths over the surface of the insulation and that within the volume of the insulation.
The current within the volume of the insulation may be further subdivided as follows
1. The capacitance charging current, of comparatively high magnitude and short duration, usually has effectively disappeared by the time the first data are taken, and it does not affect the measurements.
2. The absorption current decays at a decreasing rate from a comparatively high initial value to nearly zero. The resistance-time relationship is a power function which may be plotted on log-log graph paper as a straight line. Usually the resistance measured in the first few minutes of a test is largely determined by the absorption current.