The Kentix MultiSensor (RF, LAN, LAN-RF) is designed to detect carbon monoxide (CO) concentrations in the air.
Additional information about the CO sensor built into the MultiSensor can be found here.

In general, there are specialized sensors for all types of gases to measure and report them.
All sensors with an additional relay contact as signal output can be connected to the AlarmManager by using a KIO module (KIO3, KIO70XX).
An instruction for the connection of external sensors to the AlarmManager can be found here: Configuration of external Sensors on the AlarmManager