title: Improving short term instability for quantitative analyses with portable electronic noses.
abstract: One of the main problems when working with electronic noses is the lack of reproducibility or repeatability of the sensor response, so that, if this problem is not properly considered, electronic noses can be useless, especially for quantitative analyses. On the other hand, irreproducibility is increased with portable and low cost electronic noses where laboratory equipment like gas zero generators cannot be used. In this work, we study the reproducibility of two portable electronic noses, the PEN3 (commercial) and CAPINose (a proprietary design) by using synthetic wine samples. We show that in both cases short term instability associated to the sensors' response to the same sample and under the same conditions represents a major problem and we propose an internal normalization technique that, in both cases, reduces the variability of the sensors' response. Finally, we show that the normalization proposed seems to be more effective in the CAPINose case, reducing, for example, the variability associated to the TGS2602 sensor from 12.19% to 2.2%.
authors.affiliation: University Center of Merida, University of Extremadura, Sta. Teresa de Jornet, 38, Mérida 06800, Spain. miguel@capi.unex.es.
authors.forename: Miguel Macías
authors.initials: MM
authors.lastname: Macías
authors.affiliation: University Center of Merida, University of Extremadura, Sta. Teresa de Jornet, 38, Mérida 06800, Spain. jeagudo@unex.es.
authors.forename: J Enrique
authors.initials: JE
authors.lastname: Agudo
authors.affiliation: Polytechnic School, University of Extremadura, Cáceres 10003, Spain. antonio@capi.unex.es.
authors.forename: Antonio García
authors.initials: AG
authors.lastname: Manso
authors.affiliation: Faculty of Science, University of Extremadura, Avda, Elvas s/n, Badajoz 06006, Spain. carlos@capi.unex.es.
authors.forename: Carlos Javier García
authors.initials: CJ
authors.lastname: Orellana
authors.affiliation: Polytechnic School, University of Extremadura, Cáceres 10003, Spain. horacio@capi.unex.es.
authors.forename: Horacio Manuel González
authors.initials: HM
authors.lastname: Velasco
authors.affiliation: Polytechnic School, University of Extremadura, Cáceres 10003, Spain. ramon@capi.unex.es.
authors.forename: Ramón Gallardo
authors.initials: RG
authors.lastname: Caballero
mesh_terms: D016477:Artifacts; D032701:Biomimetics / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation*; D006801:Humans; D009666:Nose / Q000502:physiology*; D009812:Odorants / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012903:Smell / Q000502:physiology*; D014920:Wine / Q000032:analysis*