Vibrations velocity mm/s
All mechanical faults related to the machine’s rotation, such as imbalance, misalignment, or mechanical looseness, are considered low-frequency vibrations.
These vibrations are typically measured in mm/s. The most common frequency range for this type of measurement is 10 to 1000 Hz. This frequency range is also applied in the ISO 10816-3 standard, which takes into account the size of the machine and its mounting.
On the FFT spectrum is peak value of 10.4 mm/s RMS in frequency range of 10-1000 Hz. There is a clear imbalance at 49.44 Hz, indicating the need to balance the fan’s impeller. Subsequently, attention should be given to another issue at 16.5 Hz.
On the time-domain plot, we can observe an almost sinusoidal waveform within the frequency range of 10-1000 Hz, represented in mm/s. This waveform clearly indicates the presence of an imbalance. However, the sinusoidal shape is not ideal, and there are other factors at play, such as mechanical looseness, and so on.