@ARTICLE{Prokopiuk_Artur_Improving_2021, author={Prokopiuk, Artur and Bielecki, Zbigniew and Wojtas, Jacek}, volume={vol. 28}, number={No 4}, journal={Metrology and Measurement Systems}, pages={803-812}, howpublished={online}, year={2021}, publisher={Polish Academy of Sciences Committee on Metrology and Scientific Instrumentation}, abstract={The paper presents an analysis and practical study of the temperature and pressure influence on a nondispersive infrared (NDIR) sensor for measuring the concentration of carbon dioxide in human breath. This sensor is used for monitoring patients’ carbon dioxide (CO2) in the exhaled air. High precision and accuracy of CO2 concentration measurements are essential in air sampling systems for breath analysers. They, however, require an analysis of the influence of the human exhaled air pressure and temperature on the NDIR CO2 sensor. Therefore, analyses of the changes in concentration were carried out at a pressure from 986 mbar to 1027 mbar and a temperature from 20°C to 36°C. Finally, corresponding correction coefficients were determined which allow to reduce the relative uncertainty of CO2 sensor measurements results from 19% to below 5%.}, type={Article}, title={Improving the accuracy of the NDIR-based CO 2 sensor for breath analysis}, URL={http://www.czasopisma.pan.pl/Content/121809/PDF/art13_final.pdf}, doi={10.24425/mms.2021.138578}, keywords={NDIR, CO2 sensors, breath analysis, absorption spectroscopy}, }