Centrifugal compressors employ journal bearing in their design which does not allow the use of standard vibration transducers. Proximity probes must be used to monitor shaft vibration relative to the bearing case.

A standard monitoring system should have X and Y probes at each bearing. These probes should be coupled to the proper CMCP540A Vibration Displacement Monitor.

A complete vibration monitoring system includes:

For additional reading STI offers several application notes with a more in depth discussion at

STI Application Notes