OperationOrbis I.S. Optical/Heat Multisensor Detectors can be readily usedinstead of optical detectors but should be used as the detector ofchoice for areas where the fire risk is likely to include heat at anearly stage in the development of the fire.The Multisensor detector has two sensors, one for smoke and onefor heat with the alarm decision derived from either sensor orcombination of both.As with all the Orbis I.S. range of detectors the increased reliabilityof detection is combined with high immunity to false alarms.