Improvement of NDIR Carbon Dioxide Sensor Accuracy

Carbon dioxide sensors are extensively used in modern ventilation systems. Their accuracy and long term stability can crucially affect the overall effectiveness of the systems. This study is focused on the investigation of the possibilities for improving the accuracy of the most often used CO2 sensors in ventilation systems, namely the non-dispersive infrared (NDIR) sensors. An important problem with this technology is that the required light source changes its intensity over time but there are also a number of other factors which can significantly reduce the accuracy. The estimation of their impact and examination of approaches for accuracy improvement of NDIR CO2 sensors is the main purpose of this study. Finally, an experimental setup was implemented in a LabVIEW programming environment and real life measurements were carried out. The proposed methods are compared and evaluated in a quantitative way on the basis of the experimental data. The results prove that the proposed approach can improve the accuracy and reliability of CO2 concentration measurement.