High performance gas sensing of CO:: Comparative tests for semiconducting (SnO2-based) and for amperometric gas sensors

A comparison of the stability and sensitivity for two different sensor types (semiconductor SnO2 devices, amperometric electrochemical sensors) has been performed. Sensitivities and drifts in the signal and in the background for various concentrations of CO have been studied for thick-film SnO2 sensors (Pt and Pd doped) for a period in excess of 8 months. Similar performance data have been recorded for commercial amperometric sensors for a period in excess of 4 years. The two different sensor types investigated here were also compared to the well-known commercial Figaro TGS 822 sensor at similar concentrations. An objective approach for comparing different types of sensors has been developed using the "analytical sensitivity".