The OSI-RE-SS is actually a reflector- form linear optical beam smoke detector meant to work for a part of fire alarm methods. The beam operates primarily on the basic principle of sunshine obscuration utilising an Infra-Crimson beam. OSI-R-SS is really a four-wire conventional reflector-variety linear optical beam smoke detector for https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/