The beam operates totally on the theory of light obscuration using infrared. The OSI-RI detector is usually a merged transmitter/receiver which can be straight linked to an clever detector circuit in LiteSpeed® or CLIP manner. I conform to Ampac providing application updates, product updates, gives and promotions by using email https://www.firesense.co.uk/type/addressable-fire-system/addressable-beam-detectors/