Method and application
The measurement method is selected according to surface preparation and the technical specification. Roughness parameters such as Ra and Rz are assessed on machined surfaces; the surface profile of abrasive-blasted surfaces is assessed before coating. Results are compared with the limits specified for the surface.
Scope of application
- Inspection of prepared surfaces before painting and coating
- Surface profile measurement after sandblasting or abrasive blasting
- Specified roughness parameters on machined metal surfaces
- Recording of measurement areas and results outside specified limits
Ra, Rz and peak-to-valley profile height are different parameters and are not directly interchangeable. The parameter, method and acceptance limit are defined before work begins.
Reporting
Reports include measurement areas, the method and parameter used, results and assessment against the specification. Limitations arising from surface and access conditions are stated.