Gas Monitor Filters Out Water Vapor Interference

The PA4000 photoacoustic gas monitor from General Monitors of Lake Forest, Calif., is designed to provide precise high-performance gas monitoring while eliminating interference from water vapor.

The background: Water vapor can be a problem in monitoring gas. The PA4000 was created to eliminate a problem common to infrared analyzers: cross-sensitivity to water vapor. It features a sensing technique that determines the amount of water vapor in the sample and subtracts it from the gas reading. This technique allows the gas reading to be stable with no compromise to measurement sensitivity.

What: With a range of 0-1000 ppm depending on the specific configuration, the PA4000 gas monitor is accurate to plus or minus 2 ppm at 0-100 ppm and plus or minus 10 percent of reading from 100-1000 ppm, according to General Monitors. The monitor features sensitivity of 2 ppm and resolution of 1 ppm, with specifications for other ranges dependent on application. The system includes an advanced photoacoustic, infrared sensor to monitor a variety of gases, including hydrocarbons, solvents, alcohols, CO2, CO, and other dangerous gases.

The device can be configured to monitor up to eight remote areas with standard features, including a vacuum fluorescent display, audio alarm, and relays. The unit can be housed in general purpose, explosion-proof, or rackmount enclosures. It also offers standard 4-20 mA and 0-10 V outputs. The multipoint sequencer option allows expansion of the PA4000 to monitor up to eight locations with the display indicating the monitored location with its corresponding gas concentration.

Price/availability: The PA4000 is available on a quotation basis from General Monitors.