Uncertainty Evaluation of NDIR Spectrometer for Measurement od CO₂ Concentration in Air

This paper deals with measurement of carbon dioxide concentration in the air. To measure the concentration of carbon dioxide, we can choose from a wide range of measuring devices that use different measurement techniques. Evaluation of the measurement system was based on the non-dispersive infrared (NDIR) carbon dioxide spectrometer. I presented the setup of the measuring device and the solutions to eliminate obstacles which were encountered during the measurements. For the evaluation certified reference material and technical gases have been used. The measurements were performed in a range from 0 ppm to 9500 ppm. In final part, the contributions to standard uncertainty have been described, which is an essential part of any measurement. The most important contributions to measurement uncertainty have been listed, evaluated and finally stated as the total standard uncertainty of the measurement system.