Instruction Manual
760000-C
November 2002
Rosemount Analytical Inc. A Division of Emerson Process Management
Maintenance and Service 4-3
Model NGA2000 CLD
ASSEMBLED SIDE VIEW
Converter
Tube 655227
Wrap with
aluminum foil
Glass
Cloth
Sensor
Heater
Jacket
655228
Sensor
655282
Figure 4-2. Converter Assembly
4-7 DETECTOR DISASSEMBLY
Refer to Figure 4-3, page 4-5.
a. Reaction
Chamber
Removal
Disconnect the stainless steel tubing lines at
the fittings. Remove the (4) nuts holding the
Detector Assembly to the chassis. Discon-
nect the plug from connector J1 on the Sig-
nal Board and remove the assembly from the
chassis.
NOTE
Care should be taken to avoid getting
heatsink compound on optical surfaces. If
this substance is removed during the dis-
assembly process, a zinc-oxide-filled,
silicone grease (e.g., Dow Corning 340 or
EG&G Wakefield Engineering's Series 120
Thermal Joint Compound) be reapplied in
the reassembly of this component.
Although the heater and thermostat can be
removed to facilitate handling, contact with
the white heatsink compound can be mini-
mized by leaving these items in place. Re-
move the (2) screws holding the top plate of
the Detector , and move the plate along the
wires and away from the Detector .
Remove the (2) screws holding the tube
assembly in place. Hold the tubing with
one hand while inverting the Detector
Housing with the other, allowing the Re-
action Chamber O-ring and window to be
removed from below.
b. Reaction
Chamber
Installation
To reinstall, hold the housing in the in-
verted position while sliding the Reaction
Chamber O-ring and window into position
and the tubing into the slot in the housing.
Hold the Reaction Chamber in place while
rotating the housing upright. Replace the
hold-down screws.
NOTE
The procedure described above is for
the purpose of maintaining the relative
positions of windows and O-ring to the
Reaction Chamber during installation.
Replace the top cap and screws. Reverse
the removal procedure to reinstall the De-
tector Assembly into the Analyzer Mod-
ule.
