Conductivity of insulating oils

PAPERS by Doctor J. B. Whitehead and by Prof. K. F. Herzfeld present further results from the extended program of research under way at Johns Hopkins University on the fundamental properties of insulating liquids, with special reference to their use for the impregnation of paper. The general course of these studies has indicated that within the normal operating range of temperature the dielectric loss in insulating oils of the better known types can be entirely accounted for by the conductivity as measured for the very short time intervals corresponding to the period of commercial alternating circuits. In the case of impregnated paper, dielectric loss is entirely accounted for by dielectric absorption as measured under continuous potential. Doctor Whitehead´s paper is a further study of the short time conductivities, and has revealed for the first time the presence of dielectric absorption in a liquid. The influence of this on dielectric loss is examined. His own abstract follows: