The Kentix MultiSensors have a CO sensor for early fire detection. This sensor measures the carbon monoxide content of the air in ppm (parts per million).
The CO concentration of the air increases when carbon-containing minerals are incompletely burnt, e.g. in a braising fire. As this increases the CO concentration, the MultiSensor will report an alarm depending on the set sensitivity.
This allows fires to be detected at a very early stage.
Further information about the CO sensor can be found here.