Temperature-dependent dynamic response enables the qualification and quantification of gases by a single sensor

We propose a new gas sensor which obtains information from a non-linear time-dependent response. We have measured the time-dependent conductance of a sensor element for various gases, such as methane, carbon monoxide, hydrogen and butane, under periodic pulse heating at 1 s intervals. Using a small 'print type' SnO2 sensor, we are able to observe rapid and 'steady' responses with high reproducibility under fixed conditions for the sample gas. With this technique, various gas species can be distinguished and quantified. We also describe an appropriate method for processing data from the time-dependent response accompanying the change of temperature.