Electronic nose sensors

The hypothesis of a normal distribution is a strong limitation that should be always kept in mind when PCA is used. In electronic nose experiments, samples are usually extracted from more than one class, and it is not always that the totality of measurements results in a normally distributed data set. Nonetheless, PCA is frequently used to analyze electronic nose data. Due to the high correlation normally shown by electronic nose sensors, PCA allows a visual display of electronic nose data in either 2D or 3D plots. Higher order methods were proposed and studied to solve pattern recognition problems in other application fields. It is worth mentioning here the Independent Component Analysis (ICA) that has been applied successfully in image and sound analysis problems [18]. Recently ICA was also applied to process electronic nose data results as a powerful pre-processor of data [19]. 

V.K. Pamula in J. Gardner and J. Yinon (eds). Proceedings of the NATO Advanced Research Workshop on Electronic Noses Sensors for the Detection of Explosives, Warwick, Coventry, UK, 30 September-3 October 2003, NATO Science Series, II Mathematics, Physics and Chemistry, 159 (2004), 279-288, Kluwer Academic Publishers, Dordrecht. 

In a few cases, small optical infrared absorption monitors have been integrated into electronic nose sensors [11], mostly for detection of the carbon dioxide evolution from cells. The 3000-4000 nm filters are normally used. 

Tchoupo, G. N. Guiseppi-Elie, A., On padern recognition dependency of desorption heat, activation energy, and temperature of polymer-based VOC sensors for the electronic NOSE, Sensors and Actuators B-Chemical 2005, 110, 81-88. 

J.L. Solis, L.B. Kish, R. Vajtai, C.G. Granqvist, J. Olsson, J. Schnurer, V. Lantto, "Identifying natural and artificial odors through noise analysis with a sampling-and-hold electronic nose". Sensors and Actuators B 77 (2001) 312. 

Electronic Noses Sensors for the Detection of Explosives, 01-28. 2004 Khmer Academic Publishers. Printed in the Netherlands. 

The author acknowledges here the contributions of many of his colleagues, and research students. In particular, he acknowledges Professor Philip Bartlett (Southampton University, UK) for the source of some of the material taken from reference [1]. The work has also been financially supported by the Engineering and Physical Sciences Research Council (UK), The Royal Academy of Engineering, and industry. The author also thanks the NATO Science Program for the financial support to host a NATO ARW on the topic of Electronic Noses/Sensors for Detection of Explosives near Warwick University, Coventry. 

The work was supported by Lithuanian State Science and Studies Foundation. The author acknowledges the support related to the attendance at the NATO ARW on Electronic Noses/Sensors for Detection of Explosives provided by NATO Science Program. 

Electronic noses/sensors for detection of explosives will be ready for use in the field in about 4-5 years, and will be able to complement/replace existing technologies. 

The requirements of electronic noses/sensors are o Small and portable, o Sensitive, o Eow cost. 

N. Bhattacharya, B. Tudu, A. Jana, D. Ghosh, R. Bandhopadhyay, M. Bhuyan, Preemptive identification of optimum fermentation time for black tea using electronic nose. Sensors Actuators B Chem. 131, 110-116 (2008)... 

C.D. Natale, A. Macagnano, E. MartineUi, R. Paolesse, E. Proiettia, A. D Amico, The evtil-uation of quality of post-harvest oranges and apples by means of an electronic nose. Sensors Actuators B Chem. 78, 26-31 (2001)... 

Q. Zhang, S. Zhtmg, C. Xie, C. Fan, Z. Bai, Sensory antilysis of Chinese vinegars using an electronic nose. Sensors Actuators B Chem. 128,586-593 (2008)... 

Gardner J, Yinon J (2003) Electronic noses sensors for the detection of explosives. II mathematics, physics and chemistry. Kluwer Academic, New York... 

---