1.1 This practice covers the use of magnetic- and eddy-current-type thickness instruments (gages) for nondestructive thickness measurement of a coating on a metal substrate. 1.2 More specific uses of these instruments are covered by the following test methods issued by ASTM: Test Methods B 244, B 499, B 530, D 1186, D 1400, and G 12. 1.3 The values stated in SI units are to be regarded as standard. The inch-pound units in parentheses are for information only and may be approximate. 1.4 Measurements made in accordance with this test method will be in compliance with the requirements of ISO International Standard 2178 as printed in 1982. 1.5 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.