The BAPI CO2 Sensor is an accurate and reliable way of incorporating demand controlled ventilation into a building's HVAC strategy. The Dual Channel "24/7" unit has been optimized for continuously occupied areas and features a three-point calibration process for enhanced stability, accuracy and reliability. It includes a built-in Barometric pressure sensor that continuously compensates the output for accurate readings despite the weather or altitude of the installation. The BAPI-Stat "Quantum Prime" Periodic Occupancy unit comes with a large display, CO2, temperature and humidity sensing along with temperature setpoint and occupancy override. The CO2 level is indicated as "Good, Fair or Poor" by three discrete green, yellow and red LEDs on the front of the unit.