Instruction Manual
748441-D
April 2002
Rosemount Analytical Inc. A Division of Emerson Process Management
Maintenance and Service 5-27
Model CAT100
m. Basic Calibration for the Oxygen Sen-
sor
1. Admit ambient air to the analyzer of
about 21% O
2
and switch on.
2. On the OXS PCB (Figure 5-19, page
5-27), Connect the DVM to the follow-
ing measuring points:
3. TP1 (signal) and TP2 (gnd) of the
OXS PCB, mounted directly at the
connection block.
4. Set the voltage to 1000 mV (
±
5 mV)
with potentiometer R4 on the OXS
circuit board.
Do not change this
setting again!
5. Switch off the analyzer and install the
cover. Return the analyzer to the ex-
plosion proof housing.
6. Perform a complete zero and span
calibration after a sensor replace-
ment.
Figure 5-19. OXS PCB Location of Measuring Points and Voltage Adjustment
n.
Sample Pump Maintenance
The optional built-in sample pump re-
quires regular replacement of the dia-
phragm. The replacement interval is
determined by the constituents in the
sample gas which can vary with different
applications. Under normal use, the dia-
phragm should be replaced every six
months.
It is recommended that the diaphragm be
checked after the first three months of
operation to determine the optimum re-
placement frequency. If no deterioration is
noticed, check every three additional
months to determine the best replace-
ment frequency.
TP1
TP2
Potentiometer R4
