If system is fitted with a pre-filter (i.e. heated probe filter), it should be checked regularly to ensure that the element is in good condition. If element appears to be dirty or begins to cause flow restriction in the system, it should be replaced. This is a general check for any CEM system.
The Readi-GASS system has one coarse sample filter (lower) followed by one fine coalescing sample filter (upper) in the sample gas flow path which can replaced as follows.
- Loosen bolt on bottom of filter.
- Gently pull apart assembly and remove old element.
- Place new element into grooves in top and bottom of housing.
- When re-assembling, inspect for O-rings on top and bottom caps and on centre bolt.
- Install glass shell onto bottom piece.
- Place new element in groove in bottom piece. Be sure that element is seated correctly and parallel to glass shell.
- Carefully mount bottom assembly onto top piece. Slight twisting motion may be required to allow shell to slip over o-ring seal.
- Visually make sure element is seated correctly in top groove.
- Replace bolt through hole in bottom piece and screw clockwise into top piece. Do not over-tighten centre bolt. It should be just tight enough so it does not vibrate loose. Over-tightening will not help the filter to seal.
Purge Air Filters and fog Eliminator
Atmospheric air is drawn into the system and used to purge the membrane sample gas dryers. It is first conditioned by two components, one external filter with a pleated air paper style element and optional fog eliminator and one internal backup filter that can be visually monitored for particulate breakthrough coming from the external filter. Both filter housings are opened by rotating the end cap and pulling the cap off. The element can be easily changed if necessary. The fog eliminator cap should require no maintenance. However, in extremely dusty environments, it may be necessary to occasionally rinse the cap out with soapy water and check the two inlet holes and drain for any obstruction.
Nafion™ Membrane Dryer
Under normal conditions, Perma Pure dryers require no maintenance and can last for years. However, if the tubing becomes clogged with particulate matter or saturated with water, the dryer may require repair or replacement.