title: Selectivity Enhancement in Multisensor Systems Using Flow Modulation Techniques.
abstract: In this paper, the use of a new technique to obtain transient sensor information is introduced and its usefulness to improve the selectivity of metal oxide gas sensors is discussed. The method is based on modulating the flow of the carrier gas that brings the species to be measured into the sensor chamber. In such a way, the analytes' concentration at the surface of the sensors is altered. As a result, reproducible patterns in the sensor response develop, which carry important information for helping the sensor system, not only to discriminate among the volatiles considered but also to semi-quantify them. This has been proved by extracting features from sensor dynamics using the discrete wavelet transform (DWT) and by building and validating support vector machine (SVM) classification models. The good results obtained (100% correct identification among 5 volatile compounds and nearly a 89% correct simultaneous identification and quantification of these volatiles), which clearly outperform those obtained when the steady-state response is used, prove the concept behind flow modulation.
authors.affiliation: Sensor Electronic & Instrumentation Group, Faculty of Sciences, Physics Department, Moulay Ismaïl University, Meekness, Morocco. elbarbri.noureddine@caramail.com.
authors.forename: Noureddine
authors.initials: N
authors.lastname: El Barbri
authors.affiliation: Department of Electronic Engineering, University of Pamplona, Pamplona, Colombia. cmduran@unipamplona.edu.co.|MINOS, Department of Electronic Engineering, University Rovira i Virgili, Tarragona, Spain. cmduran@unipamplona.edu.co.
authors.forename: Cristhian
authors.initials: C
authors.lastname: Duran
authors.affiliation: MINOS, Department of Electronic Engineering, University Rovira i Virgili, Tarragona, Spain. jesus.brezmes@urv.cat.
authors.forename: Jesús
authors.initials: J
authors.lastname: Brezmes
authors.affiliation: MINOS, Department of Electronic Engineering, University Rovira i Virgili, Tarragona, Spain. nicolau.canyellas@urv.cat.
authors.forename: Nicolau
authors.initials: N
authors.lastname: Cañellas
authors.affiliation: MINOS, Department of Electronic Engineering, University Rovira i Virgili, Tarragona, Spain. joseluis.ramirez@urv.cat.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Ramírez
authors.affiliation: Sensor Electronic & Instrumentation Group, Faculty of Sciences, Physics Department, Moulay Ismaïl University, Meekness, Morocco. benachir.bouchikhi@gmail.com.
authors.forename: Benachir
authors.initials: B
authors.lastname: Bouchikhi
authors.affiliation: MINOS, Department of Electronic Engineering, University Rovira i Virgili, Tarragona, Spain. eduard.llobet@urv.cat.
authors.forename: Eduard
authors.initials: E
authors.lastname: Llobet
keywords: Metal oxide gas sensor; flow modulation; support vector machine; wavelet transform