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 300 ft (90 m) while simultaneously detecting a hydrogen plume fire at 50 meters. This is all done with a   fast detection speed of under 5 seconds as well as responses to flash fires in under 50 msec. Together with superior immunity to false alarms these units are keeping a SharpEye on your safety!