Fig. 3-5: Ir & Uv Photometer Assemblies With Gas Detectors - Emerson Rosemount Xstream Series Instruction Manual

X-STREAM
Photometer Assembly with Gas Detector
The design of a gas detector photometer
assembly is on principle similiar to the pyro
detector design.
One main difference is the analysis cell, that
now is lengthwise divided and both ends
sealed with windows. This separates the in-
ner volume into a sample side and a reference
side. The sample side is passed by the sample
gas, while the reference side is either filled with
air, neutral gas or reference gas, depending
on the application.
Variation 1
5
1 IR source
2 UV source
3 Analysis cells
3-8
3-1 Infrared (IR) and Ultraviolet (UV) Measurement
4 3 2
Fig. 3-5: IR & UV Photometer Assemblies with Gas Detectors
To avoid erroneous measurements absorbers
may be installed at the reference side to
suppress interfering CO
The filter cell is made as single-tier conus
system.
The gas detector has separated preamplifier
electronics, to which it is connected by a
shielded cable.
For lower measuring ranges(long analysis cells)
the preamplifier is fixed onto the analysis cell,
whereas for higher ranges it is mounted on a
special cover plate
1 5
4
5
6
Instruction Manual
traces (IR only).
2
Variation 2
6 3 4
Chopper
Detectors
Preamplifier
Emerson Process Management GmbH & Co. OHG
HASAxE-IM-HS
05/2006
1
2