1. Scope

1.1 This practice covers the use of conformable eddy-current sensors for nondestructive characterization of coatings without standardization on coated reference parts. It includes the following: (1) thickness measurement of a conductive coating on a conductive substrate, (2) detection and characterization of local regions of increased porosity of a conductive coating, and (3) measurement of thickness for nonconductive coatings on a conductive substrate or on a conductive coating. This practice includes only nonmagnetic coatings on either magnetic ? = ? ₀ ) or nonmagnetic (? = ? ₀ ) substrates. This practice can also be used to measure the effective thickness of a process-affected zone (for example, shot peened layer for aluminum alloys, alpha case for titanium alloys). For specific types of coated parts, the user may need a more specific procedure tailored to a specific application.

1.2 Specific uses of conventional eddy-current sensors are covered by the following test methods issued by ASTM: Test Methods B 244, D 1186, D 1400, E 376, E 1004, and G 12.

1.3 The values stated in SI units are to be regarded as standard. The inch-pound units are provided for information.

1.4 This 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 and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

B244 Test Method for Measurement of Thickness of Anodic Coatings on Aluminum and of Other Nonconductive Coatings on Nonmagnetic Basis Metals with Eddy-Current Instruments

D7091 Practice for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to Ferrous Metals and Nonmagnetic, Nonconductive Coatings Applied to Non-Ferrous Metals

E376 Practice for Measuring Coating Thickness by Magnetic-Field or Eddy-Current (Electromagnetic) Testing Methods

E543 Specification for Agencies Performing Nondestructive Testing

E1004 Test Method for Determining Electrical Conductivity Using the Electromagnetic (Eddy-Current) Method

E1316 Terminology for Nondestructive Examinations

G12 Test Method for Nondestructive Measurement of Film Thickness of Pipeline Coatings on Steel

ASNT Documents

AIA Standard

Keywords

coating thickness; conformable sensor; eddy-current probe; nondestructive testing; process-affected zone; Eddy current probes; Electromagnetic (eddy current) testing; Nondestructive evaluation (NDE);

ICS Code

ICS Number Code 25.220.01 (Surface treatment and coating in general)

DOI: 10.1520/E2338-04

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