Bright minds need good air for thinking. But in meeting, training and conference rooms the concentration of CO₂ soon reaches levels that cause drowsiness without anyone actually noticing. The Air Control PRO Signal's CO₂ sensor monitors air quality and responds to rising CO₂ concentration levels. Indicating air quality by means of green, amber and red LEDs, it automatically switches the ventilation ON provided it is connected to the air-conditioning system. The intelligent detector is self-calibrating, provides an acoustic warning and matches the design of STEINEL's presence detectors.