Insulator charging in SF/sub 6/ produced by impulse voltage

This work is concerned with the study of the charging process on insulators. The charges were produced by discharges inside a test-cell containing SF/sub 6/. The discharges were due to impulse voltage applied to a point-plane arrangement with the dielectric covering the flat electrode. The charging current was measured along with the impulse voltage. The surface charge deposited on the dielectric was scanned using an electrostatic probe. The results presented are concerned with the previous state of the samples (in terms of charging) associated with change in polarity and in magnitude of the applied voltage.