Copyright © VibroSystM Inc., 2006
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797L Piezoelectric Accelerometer and Cable_Installation - Rev. 1
a) Uninsulated bearing
The housing of the accelerometer is connected
to ground: do not connect the cable shield-to-
ground at the monitored end.
Figure 3: Uninsulated bearing
b) Insulated bearing
The housing of the accelerometer is isolated
from ground: connect the cable shield-to-ground
at the monitored end.
Figure 4: Insulated bearing
Step 3) Verification
1. Verify that the 797L piezoelectric accelerometer is functioning well: measure the voltage at the output of
the accelerometer (e.g. between black and white wires, at input of the PCU-100 unit). Note that the warm-
up time is about two minutes. The bias voltage (or voltage at rest) should be about 10 V
DC
(+/- 1v).
2. Much lower or higher DC bias voltages indicate internal problems and the accelerometer should be
carefully packed and returned to the factory for repair.
Figure 5: Vibrations to bias voltage
Vibrations
t
Bias Voltage = 10V
DC
