Progressive electrical surface failure in the presence of conducting liquid contaminant

In recent years, the increased use of plastics and elastomers as insulation for applications in areas where heavy surface contamination occurs both indoors and out has resulted in the development of tests to investigate the failure of materials under such conditions. Relatively few such tests have become accepted as standard and often even these are considered to be limited in scope or difficult to interpret in terms of service requirements. Much confusion has arisen because a test designed initially to evaluate one type of electrical surface failure has been indiscriminantly used to evaluate another or even "all" types.