The measurement of roughness parameters of technical surface in industry and research institutes is mainly related to 2D-profiles as described in ISO 4287, ISO 5436, etc. However in ISO 25178 a large number of functional surface parameters described are based on areal measurements.The conditions for measurement and evaluation are more flexible to allow the adaption to a larger variety of instruments to be used and types of surfaces to be evaluated. There are already some national ( e.g. Optassyst) as well as European projects (SURFSTAND; AUTOSURF, …) which have investigated the measurement of areal parameters. However this has not been done at NMI level to achieve traceability and comparability. The calibration standards suggested in section 8 reflect the necessity, to use standards for roughness representation as well standards to find out metrological characteristics of the instruments, that may influence the measurement and evaluation rules that must be agreed. Therefore we propose to use in a first step a set of available standards to set-up and to fix rules how to measure simple areal surface parameters and to achieve comparable values to 2D profile roughness data.
The methods and rules investigated successfully should be a good base to perform traceable measurements of areal roughness parameters and transferred to calibration rules to be developed in ISO/TC213.
Potential calibration standards: Optical flat for noise verification, 2d-gratings for lateral scaling and resolution test, depth standard for vertical verification, good natured profile roughness standard (SFRN 300 nm), fine ground roughness standard (Halle, 1,5 µm), areal roughness standard (Simetrics).
Progress Report 2018-10-31
The progress report can be downloaded here>>.