Glossary Balancing Technology


In balancing, the process of adjusting a machine or device so that it converts the measuring information into unbalance units referred to bearing and/or correction planes of a rotor.

Calibration mass

Defined mass in order to calibrate a balancing machine using a special rotor or to calibrate a balancing machine for a certain rotor type.

Center of mass or center of gravity

Point in a rotor with an axial and radial expansion where its inertia effect against linear distortions can be represented by a single point mass.


Design of the interface between rotor components to maintain a certain concentricity.

Centrifugal (rotational) balancing machine

Machine which generates measuring values for the unbalance caused by the centrifugal forces of a revolving rotor supported by it.


To offset an error or undesired effect.

Component correction

Unbalance correction at least at two angular positions, when in a balancing plane the correction is restricted to given angular positions.

Contract balancing

Industrial balancing services provided by a company on an as-needed basis, either production balancing or rotor unbalance evaluation.

Controlled initial unbalance

Limitation of the initial unbalance by balancing of individual components, smart design and specific machining and assembly.

Correction mass

Mass changed in a balancing plane, in order to reduce unbalance.

Correction or balancing plane

Plane perpendicular to the shaft axis, where unbalance can be corrected.

Correction plane interference or cross-effect

When change of the unbalance in one plane causes a change in the other plane. This cross-effect is expressed in percentage. The better the plane separation, the smaller the cross-effect.

Couple unbalance

Type of unbalance that displaces the main principal axis from the shaft axis and intersects the shaft axis at the center of gravity. This type of unbalance may be caused by two unbalances that are equal in amount and are exactly 180 degrees out of phase.

Critical speed

A characteristic speed, at which a resonance occurs with a rotor-bearing-system.