Determination of gases by a combined study of the resistance and noise characteristics of semiconductor sensors

A new method is proposed for improving the selectivity of semiconductor sensors based on studies of their noise characteristics. The chemisorption of gases and vapors, as well as the chemical reactions between reducing gases and air oxygen that occur on the sensor surface, make a specific contribution to the noise power spectral density. Combining the electric resistance and noise characteristics allows semiconductor sensors to be used not only for quantitative, but also for qualitative gas analysis and for odor recognition of complex samples.