Insulator Surface Charge Measurement Using an Improved Capacitive Probe

Abstract

A surface charge measuring system using the capacitive probe method is analysed. The present study shows that the measuring system cannot have a steady-state output and that the error resulting from the finite leakage resistance of the measuring system will be accumulated during the measuring process. Based on the theoretical analysis a new type probe with a low charge leakage and high resolution is designed. The surface charge accumulated on the Teflon insulator under a DC voltage is measured using this new probe and some phenomena of the surface charging are reported.