The beam operates primarily on the theory of light obscuration making use of infrared. The OSI-RI detector is actually a blended transmitter/receiver that may be immediately connected to an intelligent detector circuit in LiteSpeed® or CLIP mode. The FSP-951 photoelectric detector’s exceptional optical sensing chamber is engineered to sense smoke https://www.firesense.co.uk/type/addressable-fire-system/addressable-beam-detectors/