Pragmatics Fire Arson Detector Model 626 Trooper 2 is a dual sensor accelerant detector designed for the arson investigator. Durable MOX sensors are paired and response balanced to eliminate nuisance water vapors and pyrolitic materials vapors which are common interferences to most commercially available single sensor instruments. With sensitivity down to 1 ppm, dual sensor Pragmatics arson instruments will find trace accelerant in 85% of the samples tested. For superior drip and pour location, the Trooper 2 is fitted with an LED meter for tracing rising and falling concentrations of gas, from 1 ppm through 1% gas (10,000ppm). Requiring no field calibration prior to starting a search and start and go technology, the 626 Trooper 2 arson detector is the choice of arson investigators, insurance claim representatives, and First Responders around the world.