Optical smoke detectors incorporate a pulsing LED located in a labyrinth within the housing of the detector. The labyrinth is designed to exclude light from any external source. At an angle to the LED is a photo-diode which, in clear air conditions, does not receive light directly from the LED. The detector transmits a clear air signal to the control panel. When smoke enters the labyrinth, light is scattered onto the photo-diode and the signal to the panel increases. The signal is processed by the electronic circuitry and transmitted to the control equipment in exactly the same way as in the case of the ionization smoke detector.

• Responds well to slowburning, smouldering fires
• Well-suited to escape routes
• Unaffected by wind or atmospheric pressure

The Orbis I.S. Optical Smoke Detector works using the light scatter principle and is ideal for applications where slow-burning or smouldering fires are likely.

• Reduces false alarms
• Recommended for early warning of fire in most areas
• Improved sensitivity to black smoke
• Compensation for slow changes in sensitivity
• Algorithms for reliability of alarm

The Discovery Marine Multi-Sensor Detector consists of optical smoke and thermistor temperature sensors which give a combined signal for improved false alarm management.

• Reliable fire detection in areas with a very wide temperature range from -40°C to +70°C
• Five operating modes for customised fire detection and enhanced false alarm management
• Drift compensation to ensure constant sensitivity
• A great alternative to Ionisation detectors
• Certified to a broad range of marine approvals and EAC approved
• Assessed and certified for use in a safety function to SIL level 2

The Orbis Marine Multisensor Detector benefits from the same false alarm reduction technology as the optical detector, with the addition of a heat sensing element.

• Responds well to fastburning, flaming fires
• Reduced false alarms
• Increased reliability of detection
• Sensing chamber keeps out dust and other airborne contaminants
• Operates over a broad range of voltages at extremes of temperature
• Flashing LED option