Smoke Beams are designed as a line of sight device for areas where normal smoke detectors are not suited due to maintenance issues like height or large areas needing to be protected.
The beam detector has two parts. A transmitter/ receiver which projects a beam onto a reflective surface which is then reflected back to the main unit. Should smoke interrupt this beam a signal is sent to the FAP. Should the beam be blocked by an object then a fault signal is generated.