This standard describes two test methods for the evaluation of electrical insulating materials for use under severe ambient conditions at power frequencies (45 Hz to 65 Hz) by the evaluation of the resistance to tracking and erosion, using a liquid contaminant and inclined plane specimens. The two methods are: Method 1: test at constant voltage, Method 2: test at stepwise increased voltage. Method 1 is the most widely used method as there is less need for continual inspection. The test conditions are designed to accelerate the production of the effects, but do not reproduce all the conditions encountered in service.