Insulator surface charge accumulation under DC voltage

The phenomena of surface charging are investigated using the capacitive probe method. In order to decrease the charge leakage a new type probe with high resolution is designed. The influence of voltage amplitude, duration, polarity and surrounding humidity on the surface charging are studied. The accumulation competition between positive charges and negative charges is observed. The experimental results show that at different places on the insulator surface the surface charging has different saturation time constants.