Teledyne API Model 200AU NOX Analyzer Instruction Manual, 02293, Rev. F
8-3
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 NO2, thus causing those readings to be low.
To check and change the filter:
1. Fold down the M200AU front panel.
2. Locate the filter on the left side of the analyzer front panel. See Figure 8-1 for an
exploded view of the filter assembly.
3. Visually inspect the filter through the glass window.
4. If the filter appears dirty, unscrew the hold-down ring, remove the teflon o-ring and then
the filter.
5. 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.