BS M 40:1972

Foreword
METHODS
1. Scope
2. Terms and definitions
3. Classification of coatings and substrates
4. Underlying principles and applications of methods
     of measurement
5. General limitations
6. Safety precautions
7. Approvals
8. Testing procedures
9. Calibration standards
Appendix
A. Applicable methods of non-destructive testing

Describes methods of measuring by non-destructive means, of the thickness of single coatings, such as paint or plating on metallic substrates. Applies to the inspection of components during their manufacturing stages and when subsequently in service. Does not specify checks on the physical condition of the coatings and it should be understood that variation in these factors may affect the accuracy of thickness measurement.

1.1 This British Standard is concerned with methods for the measurement by non-destructive means of the thickness of single coatings, such as paint or plating on metallic substrates, and applies both to the inspection of components during their manufacturing stages and also when subsequently in service.

1.2 While one of the methods described can be applied to the estimation of the thickness of anodic coatings on aluminium alloys, the general measurement of the depth of conversion coatings, of corrosion, of case hardening and of decarburiza-tion is not considered.

1.3 The standard does not specify checks on the physical condition of the coatings, e.g., on their surface texture, continuity or adhesion, and it should be borne in mind that variation in these factors may affect the accuracy of thickness measurement