Description: Rotor resonant frequency calculated assuming that the rotor is supported only in the bearings and that the bearings have infinite stiffness; Name: crit speed (dry)
Description: Rotor resonant frequency calculated considering the additional support and damping produced by the action of the pumped fluid within rotor  ; Name: Wet critical speed
Description: Probability that an item is in a state to perform as required at a given instant, under given conditions, assuming that the necessary external resources are provided ; Name: Instantaneous availability