Comparison of primary standards for liquid flow - flow range (0.1 to 10) µL/min

Main text The first key comparison of liquid flow covering the actually lowest CMC entries has been registered as CCM.FF-K1.2022 (1852) at BIPM and will be finalized in 2024. The pilot laboratory is METAS and the participants have been selected according to their CMC entries, peer-reviewed publications and experience for the low flow rates. The participants are METAS, NIST, NMIJ, IPQ, CETIAT and CMS. The covered flow rate range is 0.1 to 10.0 µL/min. Two transfer standards have been selected and extensively characterized. The first one is the Coriolis flow meter ML120 from Bronkhorst High-Tech B.V., which covers the range from 5 to 10 mg/min. The second one is the thermal flow meter SLG64-0075 from Sensirion AG, which covers the range from 0.1 to 5.0 µL/min. All the measurements have been performed in the period from March 2023 to December 2023 and the analysis of the measurement results and the key comparison reference value have been completed. 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 CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).