Bently Nevada 3300/46, Operation Manual

Page: 60 / 86

0 R a m p Differential Expansion Monitor Maintenance
•
13
84414-01
Calibrate Channels [Cont]
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) b y moving i t t o the left. Measure the
voltage at test point channel A (TA) using the
multimeter. A d j u s t the power supply to ZPV
(reference Table 9). Press the GAP switch and
use the (r) and (1) switches o n the System
Monitor to adjust the voltage at TA to get +2.5
+0.03Vdc.
6. Deactivate t h e channel A z e r o adjust
dipswitch (ZA) by moving it to the right. If the
short is removed from the calibration terminals
before t h e dipswitch i s deactivated, t h e
adjustment will not be stored.
7. Repeat steps 1-6 for channel B substituting
ZB and TB
DIFFERENTIAL
EXPANSION MONITOR
G s
s
0 A L E P I e _ - , 1
. % 8 1 . S 5 4 1 k r ;
ID El
, E k t
r i 7 j , ! ; m
A ZA
/ I Z9
GA
GB
2 5