Instruction Manual
748441-D
April 2002
Rosemount Analytical Inc. A Division of Emerson Process Management
Maintenance and Service 5-11
Model CAT100
Analysis
Cell
Gas
Detector
Holding
Device Preamplifier
Holding
Device
Gas Detector
Holding
Device
Preamplifier
Absorber
Filter
Cell
Absorber
Analysis Cell
Filter
Cell
Photometer with Gas Detector
Figure 5-7 (page 5-11) shows the layout
of the photometer assembly. This assem-
bly is similar to the assembly with py-
roelectrical detector.
The analysis cells are separated into two
halves by means of an internal wall along
its axis and both ends are sealed with
windows. This divides the analysis cell
into measuring side and reference side.
Sample gas flows through the measuring
side while the closed reference side con-
tains inert gas (N
2
).
To prevent measuring errors by pre-
absorption. Two absorbers, fitted to the
gas connectors of the reference side, ab-
sorb CO
2
components.
The filter cell has a single-stage conical
shape. The gas detector is connected by
a shielded cable to a preamplifier. For
small measuring ranges, the preamplifier
is mounted at the analysis cell. For high
measuring ranges, the preamplifier is
mounted by two holding clamps.
High Measuring Range Combined With Electrochemical O
2
Measurement
Low Measuring Range Combined With Electrochemical O
2
Measurement
Figure 5-7. Photometer Assembly with Gas Detector
