ASTM B 499 : 2009 : R2026

1.1ÂThis test method covers the use of magnetic instruments for the nondestructive measurement of the thickness of nonmagnetic coatings over ferrous or other magnetic base metals. It is intended to supplement manufacturers’ instructions for the operation of the instruments and is not intended to replace them.

1.2ÂThese instruments measure either the magnetic attraction between a magnet and the basis metal, as influenced by the presence of the coating (categorized as “magnetic pull-off”), or the change in magnetic-flux density within the probe (categorized as “electronic”). These instruments cannot distinguish the thickness of individual layers. They can only measure the cumulative thickness of all layers beneath the probe down to the base metal.

1.3ÂMeasurements made in accordance with this test method will be in compliance with the requirements of ISO International Standard 2178.

1.4ÂUnits—The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.5ÂThis 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.

1.6ÂThis 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.