Teledyne API Model 200AH NO
X
Analyzer Instruction Manual, 06492, Rev. G2
8-2
8.2. Replacing the Sample Particulate Filter
The particulate filter should be inspected often for signs of plugging or contamination. It is also
common for dirt particles to absorb NO
2
, thus causing the reading to be low. A discoloration of
the filter membrane indicates that the filter is dirty and should be changed.
To change the filter:
1. Locate the sample filter on the outside rear panel.
2. Unscrew the hold-down ring, remove the Teflon o-ring and then the filter disc. See
Figure 8-1 for an exploded view of the filter assembly.
3. Replace the filter, being careful that the element is fully seated in the bottom of the holder.
Replace the Teflon o-ring, then screw on the hold-down ring and hand tighten.
