VMI VIBER X5 MKIII, Instrument Manual, Page: 45 / 121

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6. Recommended Vibration Levels
This chapter describes the ISO standard 10816-3 and which vibration levels that is
recommendable. 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 newly commissioned or after some time in operation. Investigate the
reason for any machine that vibrates above 3 mm/s RMS. Do not leave levels above 7
mm/s without analyzing cause and consequences.
0 – 3 mm/s (0 – 0, 12 in/s)
Small vibrations - None or very small bearing wear. Rather low noise level.
3 – 7 mm/s (0, 12 – 0,28 in/s)
Noticeable vibration levels often concentrated to some specific part as well as direction of
the machine. Noticeable bearing wear. Seal problems occur in pumps etc. Increased noise
level; try to investigate the reason. Plan an action during next regular stop. Keep the
machine under observation and measure at shorter time intervals than before to detect a
deterioration trend if any. Compare vibrations to other operating variables.
7 – 11 mm/s (0,28 – 0,43 in/s)
Large vibrations. Bearings running hot. Bearing wear-out cause frequent replacements.
Seals wear out, leakage of all kinds evident. Cracks in welding and concrete foundations.
Screws and bolts are loosening. High noise level. Plan action soonest. Do your best to
reveal the reason. You are wearing down investments quickly.
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 operation 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.