Method and application
Non-magnetic coatings on ferromagnetic substrates are measured using the magnetic method; insulating coatings on non-ferrous metals such as aluminium are measured using Eddy Current. A probe suited to the substrate and coating is selected. Measurements are taken in the planned areas after instrument verification and adjustment checks.
Scope of application
- Dry film thickness of hull, deck and tank coatings
- Coating inspection on pipelines, steel structures and industrial equipment
- Assessment of thickness distribution across measurement areas
- Recording of results below or above specified limits
The measurement technique depends on the substrate and coating properties. Surface roughness, curvature and edge effects are considered. For multilayer coatings, measurement generally gives the total dry film thickness.
Reporting
Reports document measurement areas, dry film thickness values, instrument and probe details, verification conditions and assessment against acceptance criteria. Areas requiring reinspection are identified.