scope:

This standard describes a procedure for determining shop or field conformance to a specified coating dry film thickness (DFT) range on ferrous and non-ferrous metal substrates using nondestructive coating thickness gages (magnetic and eddy current) described in ASTM D7091.¹ 

The procedures for adjustment and measurement acquisition for two types of gages: "magnetic pull-off" (Type 1) and "electronic" (Type 2) are described in ASTM D7091.

This standard defines a procedure to determine whether coatings conform to the minimum and the maximum thickness specified. See Note 12.1 for an example of a possible modification when measuring dry film thickness on overcoated surfaces. 

This document contains the following non-mandatory appendices:

Appendix 1 - Numerical Example of Average Thickness Measurement and Illustration of the Procedure for Determining the Magnitude of a Nonconforming Area

Appendix 2 - Methods for Measuring Dry Film Thickness on Steel Beams (Girders)

Appendix 3 - Methods for Measuring Dry Film Thickness for a Laydown of Beams, Structural Steel, and Miscellaneous Parts after Shop Coating

Appendix 4 - Method for Measuring Dry Film Thickness on Coated Steel Test Panels

Appendix 5 - Method for Measuring Dry Film Thickness of Thin Coatings on Coated Steel Test Panels that Have Been Abrasive Blast Cleaned

Appendix 6 - Method for Measuring the Dry Film Thickness of Coatings on Edges

Appendix 7 - Method for Measuring Dry Film Thickness on Coated Steel Pipe Exterior

Appendix 8 - Examples of the Adjustment of Type 2 Gages Using Shims

Appendix 9 - Precaution Regarding Use of the Standard for Coating Failure Investigations 

Units of Measure: This standard makes use of both the ASTM SI 10, "American National Standard for Metric Practice" International System Units (SI) and U.S. Customary units. The measurements are not exact equivalents; therefore, each system must be used independently of the other

¹ ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. For referenced ASTM standards visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards volume information, or to review the scope of an ASTM standard, refer to the standard's Document Summary page on the ASTM website.