The OSI-RE-SS can be a reflector- form linear optical beam smoke detector designed to operate as being a element of hearth alarm techniques. The beam operates primarily on the theory of light obscuration utilising an Infra-Crimson beam. Beam smoke detectors may be a crucial ingredient of a properly-designed automatic hearth https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/