Filter
Top Products
Instruction Manual
748332-F
April 2003
4-8 Maintenance and Troubleshooting Rosemount Analytical Inc. A Division of Emerson Process Management
Model NGA2000 NDIR
4-12 CLEANING CELLS
When zero gas is introduced in the SAMPLE IN
inlet and the Detector signal is greater 1.2V, the
cells and windows require cleaning. To do this,
follow this procedure:
See Figure 4-8 on page 4-9 to identify which
detail drawing best matches the configuration in
question.
Fold out the PCB panel.
Disassemble the optical bench according to
Figure 4-5 on page 4-5 and the cells according to
Figure 4-8 on page 4-9.
Rinse the cell with acetone. If this does not
remove all foreign matter, use a soft brush. Do
not use any metallic object inside the cell
because it will scratch the gold plating. Loss of
gold plating may require cell replacement.
After all matter has been removed, rinse the cell
with distilled water and allow to air dry. Do not
use towels.
Inspect the cell inside by holding it up to a
bright light. If particles are seen, repeat Steps
5 and 6 as often as necessary.
After cleaning cell, examine O-rings at the
source, detector and end caps. If damaged,
replace with new O-rings.
Remove any contaminants from windows with
a lint-free cloth soaked in acetone. Do not use
alcohol or other solvents. Allow to air dry.
Reverse disassemble instructions to
reassemble the unit.
Perform a leak check.
Replace desiccant if required. (See Section
4-13 on page 4-10.)
After cleaning cells, the Analyzer Module must
be optically aligned if the diagnostic values for
oscillator tune and detector signals are not
within ±5% of the factory settings. If they are
not within that range, follow Steps 7 through
10 of Section 4-11 on page 4-6.