Maintenance; Calibration And Velocity Signal Path Verification - GE Bently Nevada 86517 Operation Manual

Accelerometer Interface Module Operation Manual
This section describes a calibration procedure for the acceleration signal and
provides some troubleshooting procedures for the transducer system. To perform
these procedures you will need the following tools and instruments:
function generator, (50 ohm output)
DC power supply
multimeter
screwdriver
small screw driver
(2) 0.01 microfarad 1% capacitors, (BNC P/N 00448308)
(2) MS 3116 connectors (mates to interface module to extension cable
connector, BNC P/N 00591075)

4.1 Calibration and Velocity Signal Path Verification

Although the interface module acceleration output is calibrated at the factory, the
acceleration output can be recalibrated. Ideally the interface module should be
calibrated with an accelerometer, a shake table, and a high quality reference
accelerometer. Unfortunately this is not usually practical. This procedure uses a
voltage signal from a function generator and a capacitor to produce a charge
input to the interface module. The technique works well provided that you are in a
low EMI environment, make good connections, have a clean ground, and use a
function generator with a 50 ohm output. This is a bench procedure and it is
assumed at the start that the interface module is not connected.
Use the two connectors and the two capacitors to make a calibration assembly
as described:
1) Solder one of the capacitors to the pin C solder tail on one connector and
solder the other capacitor to the pin A solder tail on the second connector. Label
the two connectors
Use the connector/capacitor assembly in the following procedure.
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4. MAINTENANCE