Orbis multi-sensor smoke detectors are recognized as good detectors for general use but are additionally more sensitive to fast burning, flaming fires–including liquid fires–than optical detectors. They can be readily used instead of optical smoke detectors but should be used as the detector of choice for areas where the fire risk is likely to include heat at an early stage in the development of the fire.
As with Orbis optical smoke detectors the increased reliability of detection is combined with high immunity to false alarms.
Operation:
The multi-sensor smoke detector has two sensors, one for smoke, one for heat and the alarm decision is derived from either sensor or a combination of both. The multi-sensor is a development of the Orbis optical detector described in the previous chapter and goes further in its capabilities of fire detection.
The optical sensor is identical to the one in the Orbis optical detector. Its sensitivity is, however, influenced by a heat sensing element which makes the detector more responsive to fast-burning, flaming fires.
