Electric Conduction Phenomena and Carrier Mobility Behavior in Dielectric Fluids

Electric conduction phenomena and carrier mobilitybehavior in mineral base electrical insulating oiland various kinds of synthetic base dielectric fluidshave been investigated in the low voltage region andhave been compared with our results in these fluidscontaining various kinds of oil-soluble impurities.It was shown that the impurities bring about someionic conduction in the fluids, and that the carriermobilities of the fluids containing the impuritiesnot necessarily seem to be governed by Walden's rule,depending on the types of the fluids and the impurities.In contrast, the fluids with industrial puritiesobey the rule. Furthermore, it was suggestedthat an electric conduction mechanism in the fluidscontaining the impurities seems to be closely relatedto a carrier mobility mechanism in these fluids.Thus, it appears advisable that the electricalbehavior of the artificial impurities dissolved in thedielectric fluids should be dealt with apart fromthat of the natural impurities.