Optical smoke detector Orbis I.S.

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

Principle of detection: Photoelectric detection of light scattered by smoke parivles over a wide range of angles. The optical arrangement comprises an infra-red wmitter with a prism and a photo-diode at 90° to the light beam with a wide field of view. The detector’s microprocessor uses algorithms to process the sensor readings.

Main characteristics:

• 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

Operation :

The Orbis I.S Optical Smoke Detector operates on the well established light scatter principle. The remarkable optical design of the Orbis I.S. optical smoke detector allows it to respond to a wide spectrum of fires. The sensing chamber of the Orbis I.S. Optical Smoke Detector contains an optical sensor which measures back-scattered light. Sensitivity to black smoke is greatly improved. The detector is calibrated so that it is highly reliable in detecting fires but is much less likely to genereate false alarms than ionisation smoke detectors. The stability of the detector – high reliability, low false alarm rate – is further increased by the use of algorithms to decide when the detector should change to the alarm state. This removes likelihood of a detector producing an alarm as a result of smoke from smoking materials or from another non-fire source. The sensing chamber has been designed to keep out dust and other airborne contaminants.

Options

The Orbis I.S. range incorporates seven heat detector classes to suit a wide variety of operating conditions in which smoke detectors are unsuitable.

Environmental Characteristics

Operating and storage temperature: –40°C to +70°C

Operating temperature is restricted by the intrinsic safety gas classification.
Class T5: –40°C to +45°C
Class T4: –40°C to +60°C

The detector must be protected from conditions of condensation or icing.