A new contamination method for clean fog tests of composite insulators

A new artificial contamination method has been developed for hydrophobic composite insulators. It is based on mixing dry contamination particles with a low amount of atomized salt solution by means of a specially designed mixing nozzle. Unlike most of the other contamination methods developed for composite insulators, no pretreatment of the surface is needed. The salt solution precipitates on the contamination particles before they reach the surface of the insulator. This makes it possible to coat the insulator surface with a homogeneous layer of contamination without wetting the surface. The pollution process takes no longer than a few minutes and requires no special training. The proposed method is a simple, quick and effective way of artificial contamination of a wide variety of outdoor insulators.