VMI VIBER X4, Manual, Page: 25 / 58

Vibration Measurement Instruments
Recommended Vibration Levels
This chapter describes the ISO standard 10816-3 and the recommended vibration levels. It also describes
resonance and where to place the transducers for best result.
The lists and tables in this chapter can be used as a first consideration when you approach a machine that
is newly commissioned, or after some time in operation. Investigate the reason for any machine vibrating
above 3 mm/s RMS. Do not leave levels above 7 mm/s without analyzing the cause and consequences.
0 -3 mm/s (0 - 0, 12 in/s)
Small vibrations: None or very small amount of bearing wear. Rather low noise level.
3-7 mm/s (0, 12-0, 28 in/s)
Noticeable vibration levels. These are often concentrated to some specific part and direction of the machine.
Noticeable bearing wear. Seal problems occuring in pumps etc. With an increase in noise level, try to inves-
tigate the reason. Plan to take action during the next regular stop. Keep the machine under observation and
measure at shorter time intervals than before to detect if there is any deterioration trend. Compare vibrations
to other operating variables.
7-11 mm/s (0, 28-0, 43 in/s)
Large vibration levels. Bearings are running hot. Bearings wear out frequently and need replacing. Seals
wear out, leakage of all kinds is evident. Cracks in welding and concrete foundations. Screws and bolts are
loosening. High noise level. Plan to take action as soon as possible. Do your best to find the cause. You are
rapidly wearing down your investments.
11- mm/s (0,43 − in/s)
Very large vibrations and high noise levels. This is detrimental to the safe operation of the machine. Stop
operating if technically or economically possible considering the plant stop cost. No known machine will
withstand this level without internal or external damage.
Reduce any further running time to an absolute minimum.
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