Electric charge leakage from a concentric spherical air condenser

Abstract

The charge leakage from a concentric spherical air condenser can arise from two factors: an electric current flowing through insulator strings which support the inner sphere and a charge neutralization due to electrons or ions in the air. Two kinds of time constants corresponding to each factor are separately estimated, after the measurement of charge-decay time constants for varied numbers of the supporting strings. It has been found that the intensity of the leakage current through the air is ten times that of the electric conduction current through the insulators. The density of leakage current does not exceed the maximum of 10 −13 A/m 2. The decay of positive charge is faster than that of negative charge. The polarity dependence of charge leakage can be well explained by the difference between the areas of the negative electrode of each spherical air condenser. In conclusion, the electric conduction through the air in an electric field whose intensity is one-tenth to one-fifth of the dielectric breakdown strength of the air, has proved to be dominant.