Monitoring combustible or toxic gases in areas with condensing levels of moisture often results in premature sensor failure. Water condensing on sensor surfaces or within the sensor flame arrestor can be difficult to avoid due to widely variable ambient conditions.
PTT has developed a solution to this problem with a gas sampling system that also conditions the sample by removing water vapor. The Dri-Gas sampling system draws gas samples from high humidity vent stacks, ducts, wet wells, or other humid locations. The system removes water vapor from the gas sample by contact with a cold plate that condenses moisture and delivers a dehumidified gas sample suitable for toxic and combustible gas monitoring equipment. Excess condensate is pumped to a drain fitting on the bottom of the enclosure and can be collected if necessary.
Dri-Gas systems contain a diaphragm sampling pump with brushless DC motor providing operational life in excess of 10,000 hours. The pump is capable of pulling inlet line vacuum of up to 10” Hg. making it suitable for sampling duct system with negative pressures. The outlet of the pump is controlled by an adjustable rotameter allowing system sample flow to be set to the normal rate of 500 cc/min.
A differential pressure switch across the pump provides an alarm should the inlet line or outlet lines become blocked. An alarm lamp on the door provides local alarm indication and a SPDT alarm contact is available for remote alarm indication.
An optional inlet filter assembly is available for applications where gas streams may contain dust or debris that might cause problems in the air pump. A replaceable filter element on the end of the inlet assembly can be easily changed when necessary. A plugged inlet filter will be indicated by a fault indication. A package of filter elements are supplied with the inlet assembly.