Doc.Ref.No.:mVMT/om/101
masibus
Issue No. :00
Model : VM908
Operator’s Manual VM-908 Vibration meter
Page 10 of 11
02/05/16
Because this is a wide-band noise and vibration it is possible to select any frequency or frequency band as a
measurement of bearing condition.
If the selected frequency band includes low frequencies the bearing condition value would also include
vibrations from unbalances, misalignment, etc. and not purely from bearing vibrations and would therefore
be difficult to interpret.
If the selected frequency band only includes very high frequency noise and vibrations we would need special
vibration transducers that are very rigidly and closely mounted to the bearing because the machine
structure works as a mechanical filter for high frequencies.
VM-908 is measuring the bearing condition value between 1000 Hz to 5000 Hz, similar to many other
instruments. Within this frequency range there exist a common experience in the evaluation of the bearing
condition level.
