rotational frequency, f rot

in centrifugation
The number of rotations divided by time:
f rot = d N d t
The synonyms rate of rotation, rate of revolution, centrifugal speed, centrifugation speed, and the traditional units of rotational frequency such as revolutions per minute, r.p.m., ppm, rev. min −1, r min −1, are not recommended.
PAC, 1994, 66, 897 (Quantities and units for centrifugation in the clinical laboratory (IUPAC Recommendations 1994)) on page 904
PAC, 1996, 68, 957 (Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)) on page 991