A compact non-dispersive infrared carbon dioxide gas sensor with high precision and large detection range

Compared with traditional gas sensors such as metallic oxide semiconductors (MOS) and electrochemical (EC) ones, non-dispersive infrared (NDIR) gas sensors have the advantage of good stability, excellent selectivity, and long-term reliability. However, similar to all kinds of sensors, good precision (or large sensitivity) and a large measurement range cannot be reached in one NDIR gas sensor. This issue is addressed in this work by proposing a multi-channel NDIR sensor. Measurements revealed that the sensor's detection range is from 50 ppm to 10 % with a relative error less than 5 % and the relative standard deviation (RSD) of the sensor's repeatability is less than 0.4 %. These results demonstrated that the presented NDIR gas sensor can effectively detect CO2 gas with a large detection range, high accuracy, as well as excellent repeatability, offering a valuable reference for the advancement of NDIR sensors.