Vibration (amplitude vs. frequency)


When a machine is vibrating, it’s telling you there’s an internal problem – that its internal components are reacting to internal or external forces. 

But with today’s sophisticated condition monitoring technology, you can know not only that you have a problem, but what’s causing it. That’s because each mechanical defect generates vibration in its own unique way. By analyzing the specific “type” of vibration, you can identify its cause and take appropriate repair action.

When analyzing vibration, SKF looks at two components of the vibration signal: its amplitude and its frequency.

Frequency is the number of times an event occurs in a given time period (the event being one vibration cycle). The frequency at which the vibration occurs indicates the type of fault. Certain types of faults “typically” occur at certain frequencies. By establishing the frequency at which the vibration occurs, we get a clearer picture of what could be causing it.

Amplitude is the size of the vibration signal. The amplitude of the vibration signal determines the severity of the fault. The higher the amplitude, the higher the vibration and the bigger the problem. Amplitude depends on the type of machine and is measured against the vibration level of a “good” or “new” machine. 

As a world leader in rolling bearings, SKF has deep expertise in analyzing vibration data to determine the cause. This knowledge is built into SKF condition monitoring instruments and software, which we use in our own factories worldwide. By providing actionable intelligence about your machinery’s true condition, these technologies enable you to make maintenance and repair decisions with confidence.

Standard measurement methods used by SKF include:

  • Overall vibration
  • Phase
  • Acceleration enveloping
  • SEE technology (acoustic emissions)
  • High frequency detection (HFD)
  • Other sensor resonant technologies