Glossary
Radius-max (r-max)
Radius-max is the distance from the centrifuge's axis of rotation to the bottom of the tube, usually given in millimetres. It is the figure needed to convert RPM into force, and it is a fixed property of the machine and rotor you buy.
In practice
A systematic review of PRF protocols found reported radius-max values ranging from 85 to 130 mm. Because force scales linearly with radius, that spread alone produces a roughly fiftypercent difference in force at identical speed.
See also