Surface charge decay on insulators in air and sulfurhexafluorid - part II: measurements

The decay of surface charges on polymeric insulators in air and SF₆ is studied. Surface charge decay by three mechanisms, i.e. by volume and surface resistivity of the insulator as well as charge neutralization by gas ions has been simulated individually in part I. In this part the simulations of the surface charge decay are verified by experiments with insulating plates made of polytetrafluorethylen (PTFE), silicone rubber (SIR) and epoxy resin (EP). The surface charge distribution is generated by corona discharge and the charge decay is simulated by taking all three mechanisms into consideration. The influence of the test setup and particularly the size of the storage volumes on the charge decay are shown in air and SF₆.