The Wöhler IQ 300 CO₂ meter is ideal for monitoring air quality in classrooms, waiting rooms, seminar rooms, etc.. It evaluates the air quality at any time based on measurement data. An important factor for monitoring indoor air quality is the CO₂ content. Through breathing, people release moisture and CO₂ into the indoor air and, if they are sick, also viruses. A high CO₂ content in the air therefore indicates an urgent need for ventilation, because if this value is high, it can be assumed that the air is also polluted with other substances.

Via a brightly traffic light LED as well as a clearly audible tone, the Wöhler IQ 300 warns when ventilation is required. The limit values for the warning functions are adjustable. If desired, users can also mute the warning tone, as the large display also shows clearly when the air quality becomes critical.