The OSI-RE-SS is usually a reflector- variety linear optical beam smoke detector made to run as being a part of fire alarm programs. The beam operates primarily on the theory of sunshine obscuration utilising an Infra-Crimson beam. OSI-R-SS is actually a four-wire conventional reflector-sort linear optical beam smoke detector to https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/