Wheel rotor:
There is only one laterally unbalanced planar rotor. Since the rotor is only present in a known plane due to the unbalanced amount, it is only necessary to make an unbalanced measurement on the low-speed balancing machine, which can balance the balance at different speeds.

Pulley wheel:
The plane rotor has two lateral imbalances, and the two planes where the unbalanced magnitude is located are known, so it is only necessary to make an unbalance measurement in the two planes on a low-speed balancing machine, at different speeds. Meet the needs of balance.

Compressor rotor:
This is a rotor with more than two horizontal planes. After this type of rotor is assembled from two or more parts in the axial direction, it can be considered that each component is an unbalanced plane, if it is installed before. A fine balance check is made for each component, or a side-by-side balancing method is used, so that only the balance should be measured on the two calibration surfaces of the low-speed balancer when installing the rotor. More satisfactory balance effect.

Press cylinder:
This is a rotor in which the unbalanced amount is uniformly distributed in the axial direction or distributed linearly. Due to the structural arrangement, the unbalanced amount is uniform along the entire length of the rotor. It is possible to select two planes for such a rotor. Balanced on a low speed balancer, this speed will meet the desired balance.

Then how to choose these two calibration surfaces to achieve better results, need to be verified by some experiments, the analysis method is simple, only for simple cases, such as: a single span, no cantilever, and For a rotor with uniform mass and deflection and a working speed much lower than the second-order critical speed, theoretically, the better effective front position is at 22% span at both ends.