Water treeing in insulating liquids

On the assumption that water treeing activity in a heavily plasticised polymer may not differ greatly from that in a highly viscous liquid, it was decided to study the behaviour of a transparent silicone fluid interfaced with either de-ionised water or water containing 0.5 M NaCl. Alternating and direct voltages were applied to both uniform field and point-plane electrode geometries. This system allows easy optical observation and the possibility of relatively short growth times of water tree structures, so avoiding the difficulties associated with the study of water treeing in practical solid insulation such as XLPE