3.1 This test method is particularly applicable to the measurement of free films and is also satisfactory for the measurement of films on laboratory test panels.

3.2 The accuracy and precision of the thickness measurements may be influenced by the deformability of the coating. This test method is not applicable to coatings that are readily deformable under the load of the measuring instrument.

3.3 The accuracy and precision of the thickness measurements are also influenced by the uniformity of the substrate when the coatings are applied to laboratory test panels.

1.1 This test method covers the measurement of film thickness of dried films of paint, varnish, lacquer, and related products using micrometers. Procedures A and B utilize stationary micrometers and Procedures C and D, hand-held micrometers. Procedures A and C are not recommended for films less than 12.5 μm (0.5 mils) in thickness. The minimum thickness required for Procedures B and D is a function of that required to enable removal of the sample as a free film.

1.2 The procedures appear as follows:

1.2.1 Procedure A—Stationary micrometer for measuring coatings applied to plane rigid surfaces.

1.2.2 Procedure B—Stationary micrometer for measuring free films.

1.2.3 Procedure C—Hand-held micrometer for measuring coatings applied to plane rigid surfaces.

1.2.4 Procedure D—Hand-held micrometer for measuring free films.

1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.