Monitor pollution levels from 0 - 100% with any Sensaphone that accepts a 4-20ma input signal. Popular applications include schoolrooms, office buildings, and parking garages. Air Quality sensor uses a tin dioxide semiconductor sensor to detect oxidizable gases: gaseous organic materials are the components of indoor air pollutants. Air contaminants include cigarette smoke, cooking exhaust, automobile exhaust, solvents and many others. The sensor will require a 24VDC power supply such as the FGD-0053 (not included) to operate . Note: FGD sensors, accessories, etc. are not compatible with IMS-4000 systems by Sensaphone.