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

A microcontroller-based gas-sensing system is presented in this paper. The analysis presented here exploits the differences in the steady-state performance of SnO/sub 2/ gas sensors at different operating temperatures 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 the proposed approach. The results indicate that selective identification and rather accurate measurement of a mixture of CH/sub 4/ and CO gases are quite possible. 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.