The OSI-RE-SS is often a reflector- form linear optical beam smoke detector intended to function as being a ingredient of hearth alarm techniques. The beam operates primarily on the basic principle of sunshine obscuration utilising an Infra-Crimson beam. OSI-R-SS is a 4-wire conventional reflector-style linear optical beam smoke detector for https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/