Tachometer Setup - Commtest Instruments vb Series Instrument Reference Manual

Tachometer Setup

The tachometer provides the instrument with information on the
speed of rotation and the angle at which the rotor is vibrating. The
angle is measured from a fixed reference mark on the rotor and is
called the 'phase angle'. To balance a rotor it is necessary to
consider not just the amplitude of vibration but also the phase angle.
The amplitude shows the severity of the imbalance and the phase
angle indicates the geometry of the imbalance.
To set up the laser tachometer:
•
Locate the drill hole in the tachometer and screw this onto
the end of the mounting base movable arm.
•
Plug the cable socket into the tachometer connecting pins
then turn the locking ring to make a secure connection.
•
Locate the tachometer input on the instrument and attach the
other end of the cable to this.
•
Stop the rotor.
•
Cut out a small strip of the supplied reflective tape,
approximately 5 mm x 15 mm (0.2" x 0.5").
•
Stick the reflective tape to a machine part that rotates at the
rotor speed e.g. the shaft. This trigger spot should provide a
pronounced increase in reflection as it passes under the
tachometer light beam. The tape width must be at least
double the diameter of the light beam spot.
•
Mount the tachometer magnetic base to a stationary portion
of the machine, convenient to the trigger spot.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
Section 2: Basic Operation 23