Step 2. Take An Initial Reading - Commtest Instruments vbBalancer Instrument Reference Manual

Step 2. Take an Initial Reading

Stop the machine.
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Attach the sensor to the bearing housing closest to the rotor.
•
For best results attach it in the radial direction in which the
machine is most flexible (and vibrates the most).
Attach a sensor to each of the bearings supporting the rotor.
It is not important how the sensors are paired or which
sensor is attached to which end.
Set up the tachometer (see Setting up the Tachometer on
•
page 32).
Start the machine and let the rotor settle to its normal
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operating speed. Since the vibration level depends on the
speed of the rotor it is important to take all readings while the
rotor is operating at its normal speed.
From the Balance Setup Menu press
•
reading. The initial reading measures the 'out of balance'
level of the rotor.
After a few seconds, the instrument displays the speed of the
rotor in RPM and Hz, the vibration level due to the imbalance
(i.e. amplitude at 1X the rotor speed), and the phase angle of
the vibration. Note that our measurement shows an
50 Section 5: Balancing Walk-through
to take the initial