revolutions per minute (rpm)

https://doi.org/10.1351/goldbook.R05380
Non-SI unit for rotational frequency.
Source:
PAC, 1996, 68, 957. 'Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)' on page 991 (https://doi.org/10.1351/pac199668040957)