Applying the electronic nose in the environment : requirements for the sensors

For few years, the department "Environmental monitoring" at FUL applies the principle of the electronic nose equipped with tin oxide sensors to recognise and to monitor real life malodours in the environment and directly in the field.
<br />For such emissions, the gas mixtures are very complex and only their odour should be of interest, and not their chemical composition.
<br />Moreover, working in the field implies various constraints.
<br />The obstacles of the monitoring of real life environmental odours with an electronic nose can be classified into three main areas : the final goal of the study (measuring an odorous annoyance), the analysed sample itself (influenced by the evolution of the process and of ambient parameters) and the operating conditions (necessity to transport the reference gas and the batteries in the field, influence of air humidity).
<br />The paper describes the approach of FUL to the problem with various tests conducted in the field with home-made electronic noses based on tin oxide sensors and with very simple configurations. The conclusions, which can be extrapolated to any other sensor types, are promising, but the sensor performances (sensibility, reproducibility, electrical consumption, drift, etc.) should still be improved before reaching the final goal.