Measurement of potential buildup and decay, surface charge density, and charging currents of corona-charged polymer foil electrets

Abstract

Conventional measurement techniques for the investigation of the behavior of corona-charged polymer foil electrets allow one to determine the equivalent surface charge and the surface potential decay after termination of the charging process. This paper describes a technique which determines charges, currents, and potentials during the charging process. The application of this technique to Teflon and polyethylene foils show the usefullness of the method. The values of transit times and of the trap-modulated mobility for polyethylene are obtained.