This Standard provides practical test methods for the on-site determination of the range of thicknesses and the mean dry film thickness of a protective coating system, or its component coats, upon a metallic structure or fabrication. The coated fabrications to which the methods may be applied include tanks or reservoirs, bridge girders, equipment used in processing chemicals or petroleum, pipelines, and articles such as vehicles, white goods and other items of industrial production, where there is lack of uniformity of substrate thickness, metallographic character, surface condition and the film of the protective coating.