Determination of scintillation inception gradient for contaminated ceramic insulators

It is well-known that outdoor transmission lines suffer from pollution induced flashovers at the working voltage itself. Deposition of pollution and its wetting lead to nonuniform surface conductivity and hence nonuniform surface potential and temperature distributions. Theoretical calculations indicated that the highest values of the potential gradient were less than 2.8 kV/cm. To examine whether the potential gradients in the above range can trigger a scintillation, few experiments were conducted. The details of the experiments conducted and results obtained are discussed in this paper