Final report on CCQM-K19.2018 key comparison on pH of an unknown borate buffer

Abstract

Main textThis key comparison CCQM-K19.2018, as a repetition of the previous study CCQM-K19 from 2005, was performed to evaluate the degree of equivalence of measurement procedures of participating National Metrology Institutes (NMIs) and Designated Institutes (DIs) for the determination of pH of borate buffer solutions. The nominal pH value of the buffer was 9.2 at 25 °C and the suggested measurement temperatures were 5 °C, 15 °C, 25 °C, 37 °C and 50 °C. Good agreement of the results is demonstrated by most participants.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 https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).