Physical and chemical factors influencing the continuous monitoring of carbon monoxide using NDIR sensor

A Non-dispersive Infrared (NDIR) sensor for carbon monoxide (CO) was used to investigate the effects of physical and chemical factors on the accuracy of the sensor. The sensor's measurement range was 0.05 - 200 ppm. It was found that the measurement error of the NDIR at 50 ppm of CO was the lowest. Moreover, the increase of concentrations of the interferential gases (CO2, NO, NO2) led to the decrease of the NDIR accuracies. It was observed that the temperature of the inlet gas did not significantly affect NDIR measurement. On the contrary, the accuracy of the devices was gradually declined with the increase of humidity at 50 ppm of CO.