Rotating equipment requires careful monitoring to ensure that the rotating parts run within specification to prevent failures and damage. Thermaspray's desire to improve the mechanical reliability of motors and generators has led to in-service monitoring of both mechanical and electrical run-out. In-service mechanical run-out is detected through vibration monitoring and electrical run-out, by means of in-service eddy current proximity probes.
Mechanical run-out focuses more on the surface condition of the probe track area, whereas electrical run-out is concentrated around the metallurgical variations around the circumference of the shaft. These metallurgical variations lead to electrical conductivity and magnetic permeability.
For a true and accurate in-service measurement, the electrical run-out is measured and corrected prior to the assembly of the equipment.
Electrical run-out is measured and corrected by using a process called burnishing.
Typical Electrical Run-out Report