Bearing Inspection & Lubrication

Ultrasound provides an early warning of bearing or lubrication failure

Bearing condition monitoring & lubrication

Predictive & pro-active inspection of rotating equipment with an instrument such as the Ultraprobe has many advantages. An ultrasound bearing inspection program provides:

  • Early warning of bearing failure
  • Detecting a lack of lubrication
  • Preventing over-lubrication
  • Advanced software to assist your work process & analyses very efficiently

Ultrasound can be used on all bearing speeds (high, medium and low). In addition, since ultrasound is a high frequency, short wave signal, it is possible to filter out stray, confusing background noises and focus on the specific item to be inspected. Basic inspection methods are extremely simple and require little training. For those who require more sophistication, UE Systems offers training courses that range from one-day classes, on-site implementation trainings to five-day certification courses.

Analog instrument users can observe sound levels while simultaneously listening to the sound quality.  Digital instrument users have additional options such as sound and data analysis through specialized software. The more sophisticated digital instruments provide features for comprehensive bearing condition monitoring programs:

  • Data logging: DMS software for trending and setting of alarm parameters
  • Data transmission of settings: for extremely fast route based data collection
  • Sound sample recording: spectrum analysis for analyses and reporting
  • Customizable reporting formats incorporating other parameters & images
  • Data sharing: Software packages that work on a computer network

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 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.

DMS, Data Management Software

FFT of Spectralyser, Spectrum Analyses Software







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

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.

Avoiding over-lubrication using the Grease Caddy

As many as 60 to 80 percent of all bearing failures (catastrophic, functional and premature) are lubrication-related: whether it’s poor lubricant selection, poor application, lubricant contamination or lubricant degradation.  In addition to selecting the correct lubricant, use UE Systems’ ultrasound instruments to identify a lack of lubrication and prevent over lubrication conditions.

Set a baseline for each bearing, test routinely to note decibel increases.  When a bearing reaches an 8 dB gain over baseline with no change in sound quality, it is in need of lubrication.  When applying lubricant, stop when the dB level drops to baseline.  It is that easy!

The UE Systems Grease Caddy is an instrument developed specifically for supporting your lubrication practices. Advantages:

  • Cost effective instrument for lubrication engineers
  • Simple to operate
  • Keeps your hands free to lubricate with the help of mounting bracket or belt holster

Key advantages of UE Systems Ultrasound Bearing program:

Ultrasound requires limited training need:

  • Implementation process is fast & integrates easy into existing programs
  • Data Management Software easy to use and creates the reports you need
  • For each level of engineers a program to fit your needs
  • Transfer of existing programs is easy, making it long term sustainable


  • DMS and Spectralyser software packages are license & update free!
  • Regular updates available on this website for added reporting functions

Global presence & support

  • Multinational sites can be supported locally
  • Comparison of multiple plant data / benchmarking
  • Technical support available to our customers

See our learning center section for more detailed information on the subject of lubrication & bearing inspection or download our DMS software for your review.

Contact us if you like to ask for a demonstration or discuss implementation possibilities