Noise spectroscopy-based gas identifying methods to improve the selectivity of MOX gas sensors
Résumé
Air quality monitoring and analysis have become
a major issue in recent years. Metal oxide gas sensors are very
sensitive due to high variability of its resistivity in presence of
gas. However, they are not selective. It is not possible to
determinate the both gas nature and concentration using
sensors resistance variation. Noise spectroscopy is one of
solution to improve the selectivity. In this paper, we apply the
recent developed noise spectroscopy-based gas identifying
methods in order to show the possibility of each method to
discriminate the nature of different gases. Noise measurements
have been carried out on metal-oxide gas micro-sensors with
tungsten trioxide (WO3) sensing layer, under several NO2, O3
and CO concentrations in dry air. The obtained results have
demonstrated that a selective sensing of the studied gases is
possible using a single MOX gas micro-sensor.