Improving sensitivity and selectivity of SnO2 gas sensors by temperature variation

A microcontroller-based gas sensing system is presented in this paper. The poor selectivity of SnO2 sensors is improved by the consideration of temperature variation. The analysis presented here exploits the differences in the steady-state performance of SnO2 gas sensors and the potential use of such differences for improving their selectivity and sensitivity. Sets of experimental measurements of sensitivity versus temperature are used for the detailed presentation of this technique. The results shown here indicate that selective identification and accurate measurement of a mixture of CH4 and CO gases is quite possible by this method. Finally, a microcontroller-based configuration is presented as a working example of a small size implementation, which may offer measurements of improved sensitivity and selectivity along with high accuracy and reliability.