Carbon dioxide is among other things a trace gas of Earth’s atmosphere, currently having a concentration of about 400 ppm. The quantification of this gas is important from flue gases produced in combustion processes in engines, turbines and power plants. The CO₂ concentration is also an important indoor air quality parameter, and can be used for control of automatic ventilation systems.

Mid-infrared sensors are a sensitive, robust, and scalable measurement solution when CO₂ needs to be detected and measured continuously for prolonged periods of time. Depending on the needs, the measurements can be from ppm levels up to 100 volume percents.