High accuracy measurements of new conductometric metal oxide gas sensors by efficient control of working conditions

A measurement system designed for characterizing resistive metal oxide sensors based on novel materials is described. The system can simultaneously test up to 8 sensors. It exploits an ad hoc structure based on an alumina substrate equipped with electrodes, a heater and an accurate temperature sensor, on which the material under study can be easily deposited by screen prin ting, spin coating or dip coating. The system allows for studying the sensor behavior by accurately setting the operating conditions in terms of environment composition, gas flow, humidity and temperature. The system is fully programmable and it individually controls the chemical film temperatures and it measures these quan tities with a resolution close to 0.1 °C. Experimental results show that the designed system can detect the targeted gases in real-time and accurately quantify their concentrations.