Electrical Conduction in Synthetic Insulating Liquid

Electric conduction and dielectric loss of synthetic aromatic insulating liquid for capacitor use were studied. The dielectric loss was found to originate from the ionic conduction and to depend on the concentration of impurities in the liquid. The conduction phenomena of the liquid can be divided into two temperature regions. In the low-temperature region, below about room temperature, the temperature dependence of conductivity is governed mainly by ionic carrier mobility. In the high-temperature region, however, it is characterized by thermal dissociation 0of impurities as well as carrier transport process. It was also established from the identical activation energies for mobility and viscosity that the carrier mobility is governed by the viscosity of the liquid. When an artificial impurity is dissolved in the liquid, a reduction in activation energy of the conductivity is observed in high temperature and the conduction mechanism is mainly dominated by the carrier mobility; no appreciable change was obtained in the low-temperature region.