Centrifuge rotor identification and refrigeration control system based on windage

摘要

A method and system of identifying a rotor of a centrifuge employ an approach that uses two tiers of model selection. Firstly, the moment of inertia of a rotor is calculated for a first measured acceleration. The indication of moment of inertia is utilized to disqualify a number of rotor models and to select a subset of models. In a second tier, windage power of the rotor is calculated in a manner that isolates windage from inertial drag. In one embodiment, drive torque is measured with the rotor operated at a high constant speed. Alternatively, windage is calculated using data obtained during a second measured acceleration. The accuracy of the computation is enhanced by taking into account the moment of inertia as one form of resistance to the second acceleration. Based upon the indication of windage power, at least one rotor model within the subset is disqualified. Upon identification of the rotor, the centrifugal process can be maintained at a maximum safe speed. Moreover, a refrigeration offset circuit is controlled to provide a dynamic temperature correction with changes in windage power.