ASTM B244-09 (R2021) pdf free download.Standard Test Method for Measurement of Thickness of Anodic Coatings on Aluminum and of Other Nonconductive Coatings on Nonmagnetic Basis Metals with Eddy-Current Instruments.
1 .1 This test method covers the use of eddy-current instruments for the nondestructive measurement of thc thickness of a nonconductive coating on a nonmagnetic basis mctal. It is intended to supplement manufacturers’ instructions for the operation of the instruments and is not intended to replace them.
1.2 This test method is particularly useful for measuring the thickness of an anodic coating on aluminum alloys. Chemical conversion coatings are too thin to he measured by this test method.
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.
1 .5 This international standard was developed in accordance with internationally recogmuzed principles on standardization established in the Decision on Principles forthe Development of International Standards, Guides and Reconmendations issued by the World Trade OrganizaIion Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2. 1 ASTM Standards:
B499 Test Method for Measurement of Coating Thicknesses by the Magnetic Method: Nonmagnetic Coatings on Magnetic Basis Metals
3. Terminology
3.1 Definitions of Ternis Specific to This Standard:
3.1.1 accuracy, n—the measure of the magnitude of error between the result of a measurement and the true thickness of the item being measured.
3.1.2 adjustment, mi—the physical act of aligning a instrument’s thickness readings to match those of a known thickness sample (removal of bias), in order to improve the accuracy of the instrument on a specific surface or within a specific portion of its measurement range. An adjustment will affect the outcome of subsequent readings.
3. 1 .3 calibration, n—the high-level, controlled and documented process of obtaining measurements on traceable calibration standards over the full operating range of the instrument, then making the necessary instrument adjustments (as required) to correct any out-of-tolerance conditions.
3. 1.3.1 Discussion—Calibration of coating thickness instruments is performed by the equipment manufacturer, an authorized agent, or by an authorized, trained calibration laboratory in a controlled environment using a documented process. The outcome of the calibration process is to restore/realign the instrument to meet/exceed the manufacturer’s stated accuracy.ASTM B244-09 pdf download.