Patent ID: 7206719

Claim:
A diagnostic method for predicting maintenance requirements in rotating equipment normally operating in loaded and unloaded conditions, the method including the following steps; coupling a sensor to apparatus associated with said rotating equipment, said sensor being responsive to vibration in said apparatus to generate an electric signal; obtaining a load signal from apparatus associated with said rotating equipment which is indicative of whether the rotating equipment is loaded; sampling said electric signal when the rotating equipment is loaded over a predetermined sampling time interval to obtain a loaded electric signal Vl; sampling said electric signal when the rotating equipment is unloaded over a predetermined sampling time interval to obtain an unloaded electric signal Vμ; and periodically displaying the relative magnitude between said loaded electric signal Vl and said unloaded electric signal Vμ over an extended maintenance period of time, a maintenance inspection being required when the magnitude of the unloaded electric signal Vμ exceeds the magnitude of the loaded electric signal Vl.