Second Sight TC is a remote gas detection system developed by Bertin Technologies for General Monitors. It is designed to provide an additional layer of safety in the detection of combustible and toxic gases. With its high resolution infrared (IR) sensing technology, Second Sight can simultaneously detect up to four different gases and detect gas clouds as small as 2 kg at 250 m. Second Sight requires no gas calibration in the field. An automatic optical check performed every 30 minutes assesses optical path integrity, optical alignment, and the position of the focal plane. The result is a system that demands little maintenance and is immune to major sources of nuisance alarms.