Page 18 - Vibrations-2
P. 18
This shows the order spectra of the same shaft 60 Hz.
This shows the order spectra of the same shaft at 50 Hz.
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The 4 harmonic is no longer in terms of frequency but
harmonics, or orders of the fundamental rotational speed
of the machine.
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The 4 harmonic no longer shifts as the rotational speed
of the machine changes, making it much easier to monitor
the harmonics of a rotating system.
As an example, consider a car engine run-up test.
The Y-axis is the amplitude and the X-axis is frequency.
Create a spectral map.
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