This test method evaluates an insulating solid’s resistance to surface tracking and erosion caused by contaminants in the presence of electrical stress.
In the test, the conducting liquid contaminant is continuously supplied at a specified rate to the surface of the test specimen. This essentially produces continuous electrical surface discharge, which may cause specimen failure over several hours. This mimics insulation failure occurring under long-time exposure in field service. The sample under test is mounted at a 45° angle from the horizontal.