The CARBON -B1 is designed to cost-effectively control the CO2 level inside a growing area. An extremely accurate NDIR CO2 PPM sensor (part-per-million meter) is combined with a digital microprocessor to create an accurate and simple method to control supplemental CO2 use in a greenhouse. The unit can control CO2 levels up to 2500PPM. The user selects the desired CO2 level to be maintained. A built-in photocell automatically activates the unit only during the DAY. The user can also select their desired “Dead-band” setting depending on how accurately they want to control their PPM level. A pair of LEDs on the front face of the unit allows the user to quickly verify the ACTUALCO2 level +/- 50 PPM simply by counting the number of times the lights flash on and off. The “plug-box” unit is plugged into a standard power outlet, then the user connects any CO2 regulator or CO2 generator to the CARBON-B1. Once powered up and connected, the CARBON-B1 will automatically keep the CO2 at the preset level. The unit can also be easily re-calibrated by the user to ensure proper operation. Unit rated at 10 amps @ 240vac 50/60hz.