The system comprises of a single unit incorporating an infra- red Transmitter and Receiver. The signal is reflected by a prism and analysed for smoke presence. Should a predetermined level be reached, a fire condition is activated.
The system is designed to be mounted so that the beam will project between 0.3 and 0.6 metres below and parallel to the ceiling. Lateral detection may be up to 7.5 metres either side of the beam.