Replace the ozone scrubber about once every six months. Check the filter for debris accumulation once a week and then extend the checking interval depending on how dirty the sample is.
The warnings that you are getting most likely mean that you are pressurizing the inlet of the analyzer.
This analyzer works only with ambient pressure of the sample gas at the sample inlet.
Sample pressure should be dropped to about 2 psi and sent to flow controlled flowmeter
-set to about 700 cc/min and installing a thee at the inlet.
One side of the tee should be connected to the sample gas ,
the opposite side to the analyzer's sample inlet and the center should be left open to atmospheric vent.
The following is an example piping diagram that shows the analyzer and the way it's connected.