CIPM MRA COMPARISON REPORTS

This comparison was initiated by National Physical Laboratory (NPL, UK) and was designed to compare the realization of the ITS-90 at the freezing point of zinc, 692.677 K (Zn FP) through a) the calibration of two SPRTs and b) independent measurements of a transfer open zinc cell. Each participant was to use two transfer standard SPRTs to measure two Zn fixed point cells, namely their own national standard cell and a transfer standard cell (see Appendix1: Technical Protocol). The primary objective was to link NPL Zn realization to CCT-K9.

Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

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