From February 1998 to July 1999 the measurements for a Euromet project 393 were carried out. After the decision of the GT-RF (and CCEM) to extend this project into a worldwide key comparison (CCEM.RF-K8.CL with GT-RF 98-1 as its non-European part) measurements were carried out between August 1999 and December 2000.

Two travelling standards were measured by 17 national standard institutes. The results at all selected frequencies in the range from 10 MHz to 18 GHz show a good agreement between most of the participants. The maximum stated uncertainty for the calibration factor ranges from 0.3% at 50 MHz to more than 4.0% at 18 GHz, independent of the type of connector on the DUT. Almost all results are consistent within the claimed uncertainty. The uncertainty stated for the reflection coefficient was up to 0.03 in almost all cases. Most of the results are consistent within the claimed uncertainty.

The evaluation of the Euromet project led to a new comparison (project 633) to study potential problems at several laboratories. One non-European laboratory was invited to participate as well in this project (KCDB code EUROMET.EM.RF-K8.CL).

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 the CCEM, according to the provisions of the Mutual Recognition Arrangement (MRA).