Vibration measurement of rotating components is well known and largely understood due to online vibration monitoring systems such as Prosig’s PROTOR system. One major component of such systems is the ability to measure shaft vibration using non-contact probes such as eddy-current shaft proximity probes. These probes measure the distance between the probe tip and the shaft surface. One important aspect to be aware of when using this type of probe is a phenomenon known as Runout.

Runout is the combination of the inherent vibration measurement of a rotating object together with any error caused by the measurement system. Runout may consist of two components:

Mechanical Runout - An error in measuring the position of the shaft centerline with a displacement probe that is caused by out-of-roundness and surface imperfections.

Electrical Runout - An error signal that occurs in eddy current displacement measurements when shaft surface conductivity varies.

The Prosig Rotor Runout system is based on Prosig’s P8004 hardware and the DATS analysis package. The software guides a user through the process of capturing, analyzing and producing the final report.