We have found that after setting a new speed, the RPM of our centrifuges increase linearly over time to the set value. The rate of increase is constant: it is independent of the level of the "old" RPM and of the new RPM. Based on the value of the start-up time and the start-up limit, SCORES calculates the appropriate g, varying over the time steps after a new speed has been set (note that since RPM varies linearly with time, g will vary quadratically with time, until the correct level has been reached).

The delay in reaching a "set" RPM can significantly impact on your measurements, particularly in high-permeability plugs.