TECHNICAL STANDARD
ASTM D7091-22
Standard Practice for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to Ferrous Metals and Nonmagnetic, Nonconductive Coatings Applied to Non-Ferrous Metals
ASTM International
2022
Current
WHAT DOES THIS STANDARD COVER?
Covers magnetic and eddy current gauge practice for nondestructive dry-film-thickness measurement, including calibration, verification and adjustment.
WHY IS IT RELEVANT?
Useful for selecting and checking gauge practice; it does not establish project dry-film-thickness limits.
KEY INSPECTION CONSIDERATIONS
Confirm calibration and verification practices are appropriate for the gauge, substrate and coating arrangement.
WHAT THE STANDARD SHOULD NOT BE USED TO ASSUME
Using a recognised gauge practice does not set the project acceptance criteria.
PRACTICAL INSPECTION APPLICATION
Use when reviewing nondestructive DFT measurement practice against the coating specification.
RELATED TECHNICAL STANDARDS
RELATED TECHNICAL TOPICS
dry film thickness, magnetic gauges, eddy current gauges, calibration
RELATED PIL GUIDANCE
Measuring dry film thickness on abrasive blast-cleaned steel is not the same as measuring a coating on a smooth surface. ISO 19840 provides a method for accounting for the influence of surface roughness when verifying coating thickness against the specified nominal dry film thickness.
RELATED EXPERTISE
Inspection; Testing & Analysis
ABOUT THIS TECHNICAL SUMMARY
Paint Inspection Ltd provides this information to help inspectors, engineers, asset owners and contractors understand the practical relevance of commonly referenced protective coatings standards. This page is PIL technical guidance and does not reproduce or replace the published standard. Users should refer to the current published standard, project specification, coating manufacturer requirements and other applicable contract documents when establishing project requirements or acceptance criteria.
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OFFICIAL STANDARD
PIL technical summaries are intended to explain the inspection relevance of industry standards and do not replace the published document.
STATUS AND SOURCE VERIFICATION
Publisher metadata checked on 4 Nov 2026; scope recorded from the official publisher reference. PIL technical review pending.