- rpm = speed = revolutions per minute
- rcf (... × g) = multiples of the Earth’s gravitational force = relative centrifugal force
- rcm is the rotational radius measured in centimeters (cm) (distance from rotor axis to the bottom of the tube in cm)
- nrpm is the rotating speed measured in revolutions per minute (rpm)
Because this issue is very important, many convenient conversion options now exist. The best, of course, is that the centrifuge itself provides an immediately accessible rpm/rcf conversion button directly on the centrifuge operating panel. This dispenses with having to carry out complex manual calculations.
Further options include calculating nomograms using the formula shown above. To convert rpm and rcf, you will need the maximum rotor radius and either the rpm value or the rcf value. Use a ruler to determine the necessary value. Such nomograms can often be found in operating manuals or on the internet pages of well-known centrifuge suppliers, too. Automatic calculators can be found there as well.