Rotating equipment produces a sound (ultrasonic) signature during operation. This signature can be measured and trended over time. As the machine components begin to fail a change in the ultrasonic signature will occur.
The change in sound level can be used to alarm that could be related to lubrication or bearing damage. A key factor to using an ultrasound tool successfully to determine machine health is collecting the measurements at the same location every time. The first step is to identify a measurement test point for each bearing to be monitored.
One method for data collection is to use a magnet that should be attached to a metal pad epoxied to the measurement location. The use of a magnet and mounting pad will allow for repeatable and consistent data for accurate trending and alarming. If access to measurement locations is restricted, then a sensor can be permanently installed so that measurements can be taken remotely. Ultrasound is an extremely valuable tool that can be used to detect bearing problems with slow-speed applications.
Ultrasound is an important part of any reliability-based condition monitoring program and can provide early warning of mechanical failure. This early warning can lead to reduced downtime and increased plant reliability.