Instruction Manual
748441-D
April 2002
Rosemount Analytical Inc. A Division of Emerson Process Management Operation 3-17
Model CAT100
3-8 MEASUREMENT
The following summary steps must be ob-
served for the proper measurement of
sample gas concentration:
•
After switching on the analyzer, allow it
to warm up for about 15 to 50 minutes,
depending on the installed detectors.
•
Admit sample gas to the gas inlet fit-
ting.
•
Switch on the optional sample gas
pump.
•
Set the gas flow rate to the allowable
range.
•
The analyzer must be in the analysis
mode which is evidenced as follows:
If some other display mode has been se-
lected, the analyzer will automatically return
to the analysis display after a period of 60 –
120 seconds has elapsed after the last pad
activation or completion of an operation. Al-
ternately, the user can activate the FUNC-
TION pad until the analysis mode displays.
Analyzers With Electrochemical O
2
De-
tector:
The electrochemical O
2
cell requires a
minimum internal consumption of oxygen.
Sample gases with an oxygen concentra-
tion of less than 2% could result in a re-
versible detuning of sensitivity and the
output will become unstable. The recom-
mended practice is to purge the cell with
conditioned ambient air between periods of
measurement. If the oxygen concentration
is below 2% for several hours or days, the
cell must be regenerated for about one day
with ambient air. Temporary flushing with
nitrogen (N
2
) for less than one hour (ana-
lyzer zeroing) will have no effect on the
sensitivity or stability.
Channel 1 concentration
Channel 2 concentration
(if installed)
