Discrimination of Forane 134a and carbon dioxide concentrations in an air conditioned atmosphere with an electronic nose: influence of the relative humidity

Nowadays, lots of efforts are done all over the world to protect the atmosphere from the greenhouse effects. In the field of smart sensors, new applications called electronic noses are developed and used for environmental air quality control. We present here such an application based on a TGS sensor array for the detection of two main gases inducing green house effects: a new refrigerant type gas and carbon dioxide (CO2). s paper, we propose to study the influence of the relative humidity rate on the quantification of these gases and the ability of our system to successfully identify the concentration of unknown test samples. After summarising the experimental system used for the accurate characterisation of the chosen sensor array and giving the obtained experimental results, we present and compare the gas quantification results obtained with principal component analysis (PCA) and discriminant factorial analysis (DFA). We prove that the presence of humidity has a great influence on the sensor responses and the gas concentration discrimination in an air conditioned atmosphere and we show that DFA offers the best results for this quantification even that PCA is the more used method in the literature.