The OSI-RI-FL is an intelligent reflector-type linear optical beam smoke detector for use with UL- or ULC-listed compatible control panels only. The beam operates primarily on the principle of light obscuration using an infrared beam. Optical beam smoke detectors uniquely suited to protecting buildings with large open areas with high ceilings such as a warehouse or atrium. The OSI-RI-SS detector is a combined transmitter/receiver unit that can be directly connected to a intelligent detector circuit. Four LED arrows indicate the direction to move the lens, guiding the user to find the imager’s perfect alignment with the reflector. Once the optimum alignment is found, indicated by all green arrows, the lens locked with a slide lever. A paintable cover then placed over the front to secure the lever in locked position. The infrared transmitter and receiver imager generates a beam of light towards a high-efficiency reflector. The reflector returns the beam to the receiver where the received signal analysed. The change in the strength of the received signal when smoke enters the area between the unit and the reflector is used to determine the alarm condition. The receiver imager has a wide 12° field of view that automatically tracks the reflector in case of building movement or movement of its support structure. It is virtually impossible for the receiver to lose sight of the reflector from its field of view without structural damage being caused building. As a result of this operation, OSI-RI-SS is highly resistant to building movement, eliminating the number one cause of false alarms and/or faults with traditional beam detectors