Honeywell make Carbon Dioxide Gas Detector CDS2000A1000C is a CO2 gas detector for use in IAQ(Indoor Air Quality) applications, which is designed to detect carbon dioxide gas in the air. This model has a great resolution using NDIR gas detection method, so it is an optimum device for use in monitoring of CO2 levels in ventilation of building, houses, HVAC, Pharmaceuticals, chemicals, etc.