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

A comparison of the stability and sensitivity for two different sensor types (semiconductor SnO2 devices and 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 (undoped, Pt and Pd doped) over a period in excess of 8 months. Similar performance data have been recorded for amperometric sensors over a period in excess of 3 years. The two sensor types investigated here were also compared to well known commercial SnO2-based sensors at similar concentrations.