The measurement of roughness of technical surfaces is important in research and for industry. There are a lot of 2D roughness parameters that are defined and standardized by ISO. Calibration standards can be used to calibrate the instruments and ensure traceability to the SI unit of length. Most of those used are traced back to SI by national metrology institutes (NMi), which should participate in international comparison to proof the validation of measurement results.

Sixteen NMi from the EUROMET region carried out measurements on standards between May 2001 and March 2003. The set of standards used complied with ISO 5436-1 and consisted of one depth-setting standard of type A, three calibration standards of type C, three standards of type D1 and one standard of type D2. The participants aimed to measure 50 surface roughness parameters. These included the most interesting parameters in the field of surface texture, i.e. Pt, D, Ra, Rz, Rmax, RSm and Rk. Additionally, for the first time, a comparison using software gauges of type F1 that complied with ISO 5436-2 was made, taking into consideration the fact that they have an important effect on the results obtained.

In this report, results of the calibration of the standards are presented. A considerable number of the over 600 measurement results did not fulfil the E_n < 1 criterion. Some of the problems are related to the determination of the depth of grooves on the depth-setting standard. This was really not expected at the beginning of the comparison. Other problems are related to more complex parameters like RSm and Rk and their ambiguous definition in the written standards.

Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by EUROMET, according to the provisions of the Mutual Recognition Arrangement (MRA).