Good Bearing in FFT view
This is the FFT of a good bearing. Since there are no defects, the sound will be a smooth rushing sound. The FFT spectrum view will not show any harmonics or large peaks.
Bad slow speed bearing in Time Series view
This is a Time Series view of a bad slow speed bearing (less than 25 RPM). The heterodyned audio signal we can listen to gives us already a clear indication of bad condition. When analyzing slow speed bearings it may be difficult to get a good reading in FFT view. However, the defects are very apparent in the Time Series view .
Bad bearing in FFT view
This is an FFT spectrum view of a bad bearing. As a bearing enters the failure stage there is a rise in the decibel level of 12- 16 dB over a baseline. This rise in amplitude is usually accompanied by a change in the sound quality. Note that on this bearing we can now observe fault frequency harmonics which we can use to confirm & analyze. The integrated bearing fault calculator can confirm inner/outer ring, ball pass or cage defects.