Ionization-based nitrogen dioxide sensor with incorporated carbon nanotubes and temperature compensation

Abstract

The accurate and rapid determination of NO2 is a requirement for industrial monitoring and environmental protection. The ionization-based nitrogen dioxide sensor has the advantages of rapid detection, high sensitivity and wide measurement range but is affected by temperature. In this paper, an ionization-based nitrogen dioxide sensor with incorporated carbon nanotubes and temperature compensation is reported. Measurements were conducted as the NO2 concentration was varied from 0 to 3000 ppm at a 150 V operating voltage and different temperatures. The output current of the ionized NO2 sensor decreases with the NO2 concentration, but increases with the temperature. The results showed that the first ionization coefficient, emitted electrons, and secondary emitted electrons are the temperature factors affecting the ionized gas sensor. Bivariate regression analysis and regression model of least-square support vector machine were used to treat the experimental measurements. The results showed that least-square support vector machine provided a better analysis by significantly reducing the maximum fiducial error to less than 1% and greatly improved the ability of ionized NO2 sensor using carbon nanotube to correct for temperature interferences.