The Spyglass system detects hydrocarbon gases by analyzing the absorption of radiation caused by gases in the atmosphere and comparing it to background atmospheric absorption. This is accomplished between a pair of units: a Flash Source and a Detector that can monitor a distance of up to 200 meters. Spyglass Gas Detectors are robustly designed and can handle the toughest environments: 316L stainless steel housings that meet IP66/IP68 and NEMA 250 6P egress standards; circuit boards epoxy coated for protection; MIL-C-810C testing for humidity, salt, fog, vibration, mechanical shock and temperature extremes; and SIL-2 approval per IEC61508 is a final statement in reliability.