Ionisation smoke detectors are suitable for use in areas where high levels of smoke may be expected.,Optical smoke detectors incorporate a pulsing LED and a photo-diode which 'sees' the smoke and changes the alarm state.
Apollo Smoke - Fire Detectors
Series 65 conventional detectors which are designed to be aesthetically similar, and are moulded from a white polycarbonate case. The packaging is such that the lid can be used as a dust cover until the commissioning of the system. The detectors have an externally visible LED which lights up when the detector changes to alarm state.