Bently Nevada 3300/46, Operation Manual

Page: 7 / 86

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Ramp Differential Expansion Monitor Maintenance
84414-01
Calibrate Channels FCont.
1. Disconnect COM and IN wiring from the
Channel A terminals on the Signal Input Relay
Module.
2. Connect a power supply and a multimeter to
COM and IN with polarity as shown in Figure
1 on page 24.
3. Open front panel.
4. Short calibration terminals (CA) using a clip
lead (a jumper may be used if the monitor is
on an extender card). A test pattern will
appear on the display when the calibration
terminals are shorted and no calibration dip
switches are set. Both BYPASS LEDs will
come on.
5. Activate the Channel A zero adjust dipswitch (ZA)
by moving it to the left. Measure the voltage at
Test Point Channel A (TA) using the multimeter.
Adjust the power supply to ZPV (reference Table
9). Press the GAP switch and use the (t) and ( )
switches on the System Monitor to adjust the
voltage at TA to get +2.5 ± 0.03Vdc.
6. Deactivate the Channel A zero adjust dipswitch
(ZA) by moving it to the right. If the short is removed from the calibration
dipswitch is deactivated, the adjustment will not be stored.
7. Repeat steps 1-6 for Channel B substituting ZB and TB.
terminals before the
25
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