An important application of gas sensors is for the measurement of air pollutants, concentrations of which are usually in the low ppb range. To obtain good sensitivity and selectivity to certain polluting gases with semiconductor gas sensors is not very straightforward at the moment. Some Ag-doped SnO2 thin-film sensors have been used in this study to monitor the H2S concentration as a polluting agent, both in laboratory air and in a city atmosphere (Oulu, Finland). A sensor array construction consisting of four sensors has been installed at a city air-pollution monitoring station where the H2S and SO2 concentrations are being simultaneously recorded by commercial analysing equipment based on Coulometric titration together with the signals from the semiconductor gas-sensor array. The preliminary results support the conclusion that the Ag-doped thin-film sensors running in the constant-temperature mode at around 150 °C may be useful for monitoring H2S concentrations present as a pollutant in city air.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry