Monodispersion Soot Interference Attached on the Protection Windows on NO2 Concentration Accuracy Using NDIR
NDIR method is one of the important nitrogen dioxide concentration measurement methods. The soot attached on the protection windows, the original and the transmission light intensity on the nitrogen dioxide is attenuated because of the soot absorption and scattering and the received nitrogen dioxide Characteristic absorption wavelength light intensity is deviated from the theoretical absorption light intensity, so the nitrogen dioxide concentration measurement accuracy is decreased. The protection window pollution interference caused by the monodispersion soot is discussed in this paper. The numerical simulation based on the Mie theory results show that the nitrogen dioxide concentration measurement accuracy is related to the soot concentration, soot average diameter, soot diameter distribution and so on. The solution method of the windows monodispersion soot pollution interference is brought out and the nitrogen dioxide concentration measurement accuracy can be improved.