1. Unbalance
The magnitude of the unbalance on a certain plane of the rotor does not involve the angular position of the unbalance. It is equal to the product of unbalanced mass and its center of mass to the axis of the rotor. The unit of unbalanced quantity is gmm or gcm.
2. Unbalanced Phase
The angle value of the unbalanced mass on a certain plane of the rotor relative to the given polar coordinate.
3.Initial Unbalance
The amount of unbalance that exists on the rotor before balancing.
4. Correction Radius
The distance from the center of mass of the correction mass on the correction plane to the axis of the rotor is generally expressed in mm.
5.Rotor balance quality
A measure of the pros and cons of rotor balance.
         G=eperω/1000
Where
         G-rotor balance quality, unit mm/s. There are 11 levels from G0.4-G4000.
         eper-Allowable rotor unbalance rate gmm/kg or rotor mass eccentricity μm.

     ω-the angular velocity corresponding to the maximum working speed of the rotor = 2πn/60≈n/10, where n is the working speed r/min of the rotor.