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ADASH Ltd.
How to evaluate the failure
The instrument shows measurement results on several separate screens. We shall describe basic
rules for their use.
Overall RMS values
- Machine symbol - this line shows a RMS velocity vibration value in mm/s or ips, which is
excited on the machine by mechanical phenomena related to:
- imbalance of rotational parts of the machine (fan wheel, impeller, clutch wheel etc.),
- incorrect axis alignment of the assembly – misalignment,
- mechanical looseness of individual machine parts,
- large free play in seating of rotational machine parts (shaft - bearing, shaft – bearing
housing),
- clutch free play (e.g. free play on a shaft, pressed out grooves and tongues),
- loose or worn out machine anchor bolts,
- defective base,
- insufficient frame or anchoring flange rigidity,
- damage to machine rotation parts - (bent shaft).
- Bearing symbol – this line shows a RMS acceleration vibration value on g, which is excited by
a condition of bearing. This condition is related to:
- time wear of the bearing,
- bad lubrication (with new bearings as well),
- incorrect installation (with new bearings as well),
- abrading of bearing.
SPEED - The machine speed is displayed at the bottom part of the screen (if it is available). RPM
means revolutions per minute. The instrument performs automatic determination of machine
revolutions using a spectrum analysis. This function does not have to be always successful, because
the revolutions may not be possible to read for every spectrum. If the speed is not determined, it is not
a malfunction. It is hard to do it, for example, in machines with gears.
If the speed is available, then
vibration limits. Machine conditions are divided into 3 levels, which have the same colours like traffic
lights:
1.GOOD – GREEN COLOUR
Machine is in good condition, no defect is found. The operation is without restrictions.
2.ALERT - AMBER COLOUR
The beginning defect is found on the machine. It is possible to operate with paying more attention and
planning of repair.
and
vibration values have been coloured corresponding to
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Adash 4900 – Vibrio III
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