Instruction Manual
748441-D
April 2002
Rosemount Analytical Inc. A Division of Emerson Process Management
Maintenance and Service 5-29
Model CAT100
5-5 ANALYZER SERVICE
Be sure to observe appropriate safety precau-
tions when working on powered equipment.
All measuring points are measured against
ground (X 11, X 28, or X29).
a.
Test Points for BKS PC Board
Supply V 6 V
Test Point:
X 14
Test Device: DVM
Signal:
+ 6 V DC (+10/-200 mV)
(Adjust with potentiometer
R90 if necessary)
Failure: No
signal
Possible
reasons:
Voltage supply absent
Voltage supply < 9 V or
polarity reversed.
BKS PCB faulty
Reference Voltage Positive
Test Point:
X 10
Test Device: DVM
Signal:
+ 5.535 V DC (
±
60 mV)
Reference Voltage Negative
Test Point:
X 12
Test Device: DVM
Signal:
Inverse of reference
Voltage positive
The difference between the negative and
positive reference voltage must be no
more than 10 mV (U
ref+
+ U
ref-
≤
±
10 mV)!
If the difference is larger, replace the BKS
PCB.
Figure 5-21. BKS PCB Test Points
X16
X18
X14
X9
X28
X29
X10 X12
X11
X8
X27
1
X25
LB1
U2
U1
U3
Front Panel