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.
Figure
Radius-max
Figure. The distance from the axis of rotation to the bottom of the tube. Across the reviewed literature, reported values range from 85 to 130 mm. Because force scales linearly with radius, that spread alone produces roughly a fifty percent difference in force at identical speed.
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