A number of the later model centrifuges now have the functionality which allows the operator to automatically convert between RPM and RCF. For those centrifuges that do not have this feature, there are several ways to make this conversion:
- Use a nomogram or conversion table
- Use online converters
- Refer to the centrifuge user's manual
- Manually make the calculations
Before any of the above methods can be implemented to make the conversion, the measurement of the radius of the rotor must be determined. This measurement is from the axis or center of the rotor to the bottom of the tube holder, as depicted in Figures 1 and 2. This may be attained by using a measuring device and manually measuring the radius. However, many manufacturers now include this information in their centrifuge user manual.