The OSI-RE-SS is a reflector- style linear optical beam smoke detector meant to work for a part of fire alarm systems. The beam operates totally on the basic principle of light obscuration utilising an Infra-Crimson beam. Beam smoke detectors could be an important part of the nicely-created automated hearth alarm https://www.firesense.co.uk/type/conventional-fire-system/conventional-beam-detectors/