The OSI-RE-SS is actually a reflector- type linear optical beam smoke detector built to function to be a part of fire alarm programs. The beam operates primarily on the principle of sunshine obscuration utilising an Infra-Red 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/