Abstract. The results are presented of key comparison CCM.P-K2 that covered the pressure range 10 kPa to 120 kPa in absolute mode. Nine national measurement institutes participated in the comparison, which used a piston–cylinder assembly of 335 mm² nominal effective area as a transfer standard.

Whilst not all laboratories were found to be equivalent at all pressures, the larger-than-expected instabilities in the transfer standard precluded the ability to discriminate between participants' standards at a level needed to fully support the Calibration Measurement Capabilities table in the BIPM key comparison database.

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