Instruction Manual
748441-D
April 2002
3-12 Operation Rosemount Analytical Inc. A Division of Emerson Process Management
Model CAT100
3-4 CALIBRATION
To insure correct analyzer measurement,
zeroing and spanning should be performed
at least once per week. The span calibra-
tion must be performed after the zeroing.
For either manual or automatic calibration,
the required test gases must be fed to the
analyzer through the respective gas inlets
with a no-back-pressure flow rate of about
1 l/min, the same as the sample gas.
NOTE:
After switching on the analyzer, wait at
least approximately 15 to 50 minutes
(depending on installed detectors) for
instrument warm up before feeding gas
to the analyzer.
NOTE:
If the optional internal or external sole-
noid valves are installed, the valves are
automatically actuated by digital outputs
for the respective function. If the ana-
lyzer is in “calibration mode,” an op-
tional digital status signal “calibration”
output is activated.
a. Zeroing
For zeroing, the analyzer has to be
flushed with nitrogen (N
2
) or an ade-
quate zero gas such as synthetic or
conditioned air. Air cannot be used for
oxygen zeroing.
b. Spanning
The span gas concentration should be
in the range or 80% to 110% of the full
scale range of the analyzer. If lower
span gas concentrations are used, the
measuring accuracy for sample gas
concentrations higher than the span
gas concentration will be compromised.
Spanning for oxygen measurement can
be done using ambient air as span gas,
if the oxygen concentration is known
and constant.
NOTE
When using span gas mixtures, the
entry for “C.Cal” must be set to “0”
(see Section 3-3c, page 3-7)! If there
is no built-in pressure sensor, the
correct pressure must be entered
before performing the calibration, if
it is desired to have pressure correc-
tion (see Section 3-3a, page 3-7)!
