Nine national metrology institutes (NMIs) and three commercial laboratories participated in this first formal S-parameter comparison of the coaxial 2.4 mm line system. Measurements of the S-parameters were made at 63 frequencies in the range from 50 MHz to 50 GHz for three attenuators, two matched loads and two mismatch standards. For a subset of seven selected frequencies ('Annex Data') the laboratories were asked to quote uncertainties. In addition the participants had to perform at least four connector orientation measurements ('Connector Orientation Data') and to provide the results of mechanical pin depth measurements of the 2.4 mm connectors.

For the 'Annex Data' a comparison reference value (CRV) is determined using multivariate statistical methods and Monte Carlo technique. The complete 'Annex Data' and the results of the CRV analysis are presented in this report together with the results of a statistical analysis of the 'Connector Orientation Data'. Also shown are results of the pin depth measurements.

Due to the amount of data it is not possible to show the full data set at all frequencies and connector orientations in this report. The complete comparison data set and additional information are however available on a CD-ROM, which has been distributed among the participants together with the first version of draft A. Included are tools that allow visualization and comparison of the data sets. The CD-ROM is only available to the participants in the comparison exercise as it contains confidential, pre-publication, information.

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).