Dielectric absorption and theories of dielectric behavior

OF the various component parts entering into electrical systems of all characters, the insulation is the least susceptible to exact computation and design. In few, if any cases of even simple and pure materials are the dielectric properties, resistivity, dielectric strength, specific inductive capacity, either constant or uniform; and in the cases of composite and fabricated insulations of manufacture the variations are extremely wide. As results, in all cases liberal factors of safety to cover the worst probable conditions must be allowed, resulting further in increased size and cost, and in undesirable magnitudes of other properties, such as dielectric loss and phase difference, volume and surface conductivity, circuit capacity and conductance, etc. Little if any attempt has been made to control the inherent characteristics of simple dielectrics, or to study their influence in combinations. Physicists appear to have all but forgotten the unsolved problems of dielectric behavior, or perhaps to have given them up. The control of manufactured insulation appears to be limited to heat treatment, principally for the purpose of elimination of moisture — a sufficiently important object — and to the obtaining of pure raw materials. Studies of the properties of these materials in their bearing on those of the composite final form of the insulation have not appeared in any quantity.