1.1 This test method covers the nondestructive measurement of the mass per unit area of coating using beta backscatter gages. It also covers the measurement of the linear thickness if the coating density is known.

1.2 This test method applies to both metallic and nonmetallic coatings on both metallic and nonmetallic substrates.

1.3 This test method is applicable only if the atomic numbers or equivalent atomic numbers of the coating and the substrate differ by an appropriate amount (see 6.2).

1.4 This standard does not purport to address all of the safety problems 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. See specific hazard statements in Section 7.