Improving sensitivity and selectivity of SnO/sub 2/ gas sensors by temperature variation

We present a microcontroller-based gas sensing system. The poor selectivity of SnO
₂
sensors is improved by the consideration of temperature variation. The analysis presented here exploits the differences in the steady-state performance of SnO
₂
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 CH
₄
and CO gases is quite possible by this method. Finally, a microcontroller-based configuration is presented as a working example implementation, which may offer improved sensitivity and selectivity accuracy and reliability