Quantitative gas detection with semiconductor micro-sensors and chemometrics

The use of the chemometric techniques to exploit the selectivity of gas sen sors, although current in the case of multisensors systems, is tested here with only one gas sensor. The method consists in measuring the electric con ductance of the sensitive element, a tin dioxide bar, at various temperatur es. Although these gas sensors follow non linear laws, the modelization alg orithm Partial Least Square (PLS) is preferred to neural networks. A compar ison of the two algorithms is made, as well as a study of the portability o f the model and stability of the prediction. Lastly, the concept is tested on an autonomous prototype in real conditions.