The Opal addressable beam detector is an intelligent reflector
type linear optical beam smoke detector designed to operate
with Notifier addressable fire alarm systems. It operates
primarily on the principle of light obscuration utilising infra-redlight.
The Infra-Red transmitter generates a beam of light towardsa high efficiency reflector. The reflector returns the beam tothe receiver where an analysis of the received signal is made.The change in the strength of the received signal is used todetermine the alarm condition.