How Ultrasound Bearing Inspection Works

Mechanical movements produce a wide spectrum of sound. One of the major contributors to excessive stress in machinery is friction.  Ultrasound instruments detect friction.  By focusing on a narrow band of high frequencies, the Ultraprobe from UE Systems detects subtle changes in amplitude and sound quality produced by operating equipment. It then heterodynes these normally undetectable sounds down into the audible range where they are heard through headphones and observed on a display panel for trending, comparison, and analysis.

It has been established that ultrasound monitoring provides early warning of bearing failure. Various stages of bearing failure have been established. An 8 dB gain over baseline indicates pre-failure or lack of lubrication. A 12 dB increase establishes the very beginning of the failure mode. A 16 dB gain indicates advanced failure condition while a 35-50 dB gain warns of catastrophic failure.  For those who utilize ultrasound spectral analysis, these conditions can often be observed through both FFT and time series analysis.

Ultrasonic Bearing Inspection Methods

There are three methods for ultrasonic bearing monitoring:

  • Comparative: Compare same type bearings and note deviations, easy & fast to do
  • Historical: Establish a trend over time of measured values with the help of DMS Software
  • Analytical: Utilize Spectralyser software with the integrated bearing fault calculator


DMS, Data Management Software

With the Historical method & using the DMS Software we are able to also program alarm levels in our data points:

  • Establish a baseline reading
  • 1st alarm = indication of lack of lubrication
  • 2nd alarm = early warning of bearing failure

After an upload of new data from a route, reporting functions in the software will help you to produce fast and easy a lubrication report.

Contact UE Systems if you would like to ask for a demonstration or discuss implementation possibilities.