The Quad-Sense technology uses four independent IR sensors all placed in the invisible infra-red spectrum to detect hydrocarbon fires as well as Hydrogen fires at the same time. Using this unique technology Spectrex creates an enhanced performance, advanced long-distance detection of hydrocarbon fires up to 215 ft (65 m) while simultaneously detecting a hydrogen plume fire at 30 meters. This is all done with a fast detection speed of under 5 seconds. Together with superior immunity to false alarms these units are keeping a SharpEye on your safety!