Large (expansive) commercial building atriums lend themselves to projected beam smoke detection systems. Most systems of this type require point-to-point beam detectors that can be vulnerable to faults and nuisance alarms if not installed and maintained correctly. Installed by Firewize, OSID by Xtralis helps overcome many of the inherent weaknesses of typical beam detectors bu using a combination of dual wavelength projected beams and optical imaging technology.