AZ Instrument Carbon Dioxide(CO2) Monitor and Controller AZ7530UK Plug Version Also known as CO2 meter or Carbon Dioxide detector, widely used for indoor air quality and greenhouse CO2 measurement. Application: For greenhouse highly accurate digital CO2 controller measures the carbon dioxide level in the grow room and automatically turns on off the CO2 generator to accurately keep the CO2 PPM at the desired level For home use measure the carbon dioxide level in closed space and automatically turns on off