A method for ranking dielectric liquids subjected to AC power voltage

The authors describe a test method to evaluate the breakdown properties of various dielectric liquids, with the view to determine their applicability in high voltage apparatus. The authors develop a method to characterize the properties of dielectric liquids along the following guidelines: AC voltage, moderately divergent fields of low mean values. To trigger the breakdown at such low fields, they simulate a defect by introducing a calibrated large metallic particle in the gap. This large particle constitutes obviously an oversized defect, but it allows them to reproduce several experiments in the same conditions