Rosemount open path gas detectors

Emerson has released two open path gas detectors to increase safety over wide areas in extreme environments. Extreme environments include both heavy vibration conditions and operating temperatures ranging from -55°C up to 65°C commonly found in the oil and gas, refining, chemical, mining and large-scale refrigeration system operations.

The Rosemount 935 Open Path Combustible Gas Detector uses infrared technology to detect a wide range of combustible hydrocarbon gases, including methane, propane and ethylene. In the oil and gas industry alone, 22% of all fatalities come from explosions or fire and exposure to hazardous gases.

The Rosemount 936 Open Path Toxic Gas Detector uses ultraviolet technology to detect hydrogen sulfide and ammonia, two of the most common toxic gases in industrial facilities. Leveraging xenon flash technology, the Rosemount 936 enables greater installation flexibility versus the tunable diode laser (TDL) technology, which needs perfect alignment between beam and receiver for high reliability.

Open path detection technology uses a source and a detector. The source sends a modulated light beam across the monitored space and the detector senses the amount of light absorbed by the presence of gas. This approach provides a high degree of coverage across wide areas up to 200 m in length with accurate measurement, even if the toxic or combustible gas cloud is drifting at any point between the devices or when 95% of the light beam is obscured by fog, rain or smog. The system also will alert if the path is blocked completely by a physical obstruction.