330400 and 330425 Accelerometer Operation Manual
3. Maintenance
This section shows how to check the performance of the 330400 and 330425
Accelerometers. Table 3-1 lists the recommended maintenance equipment. If the
equipment is not available, contact the nearest Bently Nevada field office, or
return the transducer to the factory or a testing laboratory for testing.
Table 3-1. Recommended Maintenance Equipment
Recommended Equipment S p e c i f i c a t i o n
A Shake Table
Bently Nevada Monitoring Systems:
3300, 2201, or 3500
A Voltmeter
3.1 Performance Test Procedure
Step 1:
Mount the accelerometer on a shake table.
Step 2:
Connect the cable to the accelerometer and the monitor as shown in
section 2.
Step 3:
Shake the accelerometer at 100 Hz with a known acceleration level.
Step 4:
Verify the accelerometer output on the monitor or a Voltmeter.
Note:
The accuracy of the system can be improved by calibrating the
monitor and the shake table separately before performing the system
loop check.
3.2 Polarity Test Procedure
Use this test to verify the proper phase response. An improper phase will
adversely affect the use of the accelerometer for machinery diagnostics.
Step 1:
Power up the accelerometer as shown in Figure 2-5.
Step 2:
Set the time base on the oscilloscope to 20 milliseconds/division.
Step 3:
Hold the transducer in hand and tap the bottom. Observe that the
waveform on the oscilloscope first goes positive as shown in Figure 3-1. If the
wave form goes negative first, contact the nearest Bently Nevada office for
assistance.
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Summary of Contents for Bently Nevada 330400
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