4.1 By use of this test method and Test Methods D1500 or D2129 the color and condition of a test specimen of electrical insulating liquid may be estimated during a field inspection, thus assisting in the decision as to whether or not the sample should be sent to a central laboratory for full evaluation. Cloudiness, particles of insulation, products of metal corrosion, or other undesirable suspended materials, as well as any unusual change in color may be detected.

1.1 This test method for visual examination is applicable to electrical insulating liquids that have been used in transformers, oil circuit breakers, or other electrical apparatus as insulating or cooling media, or both.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.