Développement d'un instrument d'évaluation des impacts de matériaux sensibles aux moisissures sur la qualité de l'air intérieur.

Report (2004)

In the frame of a FIRST-Europe project, the research team worked with a partner from university of Barcelona (Spain) and a company fabricating products to reduce moisture problems in dwellings. An ... [more ▼]

In the frame of a FIRST-Europe project, the research team worked with a partner from university of Barcelona (Spain) and a company fabricating products to reduce moisture problems in dwellings. An original instrument was designed. It was based on the "electronic nose" principle. With suitable data processing tools and an adequate calibration, the instrument was able to distinguish, from the analysis of the gas phase, the emission of the clean material from the one of the same material contaminated by moulds and from the one of the product against humidity. Discriminating between different mould species was more difficult. [less ▲]

Establishing the limit of detection and the resolution limits of odorous sources in the environment for an array of metal oxide gas sensors

in Sensors and actuators. B, Chemical (2004), 99(2-3), 384-392

Odour identification with gas sensor arrays relies on two main parameters: the limit of detection, defined as the concentration of the analyte corresponding to the lowest detectable signal for the sensors ... [more ▼]

Odour identification with gas sensor arrays relies on two main parameters: the limit of detection, defined as the concentration of the analyte corresponding to the lowest detectable signal for the sensors, and the limit of resolution, defined for pair-wise comparisons of vapours, as the concentration levels below which a vapour can no longer be reliably recognised from another one on the basis of its response pattern. For real-life environmental odours, however, it is no longer possible to express such limits in "concentration" terms, because they are complex gas mixtures composed of hundreds of various compounds. The paper tries to assess both limits for odorous sources in the environment firstly by finding an equivalence of the odour concentration, expressed in odorous unit per cubic meter (ou/m3), and the concentration of a reference gas, here the ethanol, and secondly by working with a statistical metric, based on the magnitude and standard deviations along linear projections of clustered response data. The methodology is illustrated for a metal oxide gas sensor array and the odour generated by urban waste composting facilities, which is compared to the background air and to ethanol vapour. [less ▲]

Adaptation et test d'un nez électronique pour suivre en continu la nuisance olfactive générée par un centre de compostage

in Revue scientifique des instituts supérieurs industriels libres francophones (2004), 18

L'article présente le travail de fin d'études de Catherine Ledent. Celui-ci a consisté à la mise au point et au test sur le terrain (sur le centre de compostage à Habay) d'un nez électronique destiné à ... [more ▼]

L'article présente le travail de fin d'études de Catherine Ledent. Celui-ci a consisté à la mise au point et au test sur le terrain (sur le centre de compostage à Habay) d'un nez électronique destiné à être placé en continu sur un site industriel, de manière à détecter des occurrences d'odeur. Le prototype existant a été adapté de manière à satisfaire aux exigences du terrain. Par exemple, une régulation thermique de la chambre des capteurs a permis de s'affranchir des variations de température de l'ambiance. La phase de validation sur le terrain fut la plus exigeante: elle nécessitait en effet une présence constante de l'étudiante sur le terrain, de manière à identifier les causes possibles de variation des capteurs. En finale, le système a montré d'excellentes performances et peut servir de base à un développement technologique ultérieur. [less ▲]

La modélisation de la dispersion atmosphérique. Cas particulier des odeurs.

Report (2003)

The report was written in the frame of a general project concerning the "plan of air in Wallonia", aiming at inventory the policies, standards and measurement methods concerning the air quality. The ... [more ▼]

The report was written in the frame of a general project concerning the "plan of air in Wallonia", aiming at inventory the policies, standards and measurement methods concerning the air quality. The present report refers to the atmospheric dispersion models and their particular use to simulate the odour plumes. [less ▲]

Fuzzy K-NN applied to moulds detection

in Proceedings of ISOEN'03 (2003, June)

The possibility to detect Aspergillus versicolor growing on different building materials by a metal oxide sensor array is studied. Results show that an accurate classification rate of 89 +/- 3% can be ... [more ▼]

The possibility to detect Aspergillus versicolor growing on different building materials by a metal oxide sensor array is studied. Results show that an accurate classification rate of 89 +/- 3% can be obtained combining an extended linear discriminant analysis plus a fuzzy k-NN classifier. The classification ability of the classifier is assessed within the dataset by crossvalidation and also in a second dataset collected 5 months later. There is a slight decrease in the classification performance for all the algorithms, being the most sensitive the most accurate one. [less ▲]

Analyse physico-chimique des odeurs de la stations d'épuration d'Arlon

Report (2003)

The use of sensor arrays for environmental monitoring: interests and limitations

in J. Environ. Monit. (2003), 5(6), 852-860

Continuous, in situ monitoring of air, water and land quality is fundamental to most environmental applications. Low cost and non-invasive chemical sensor arrays provide a suitable technique for in situ ... [more ▼]

Continuous, in situ monitoring of air, water and land quality is fundamental to most environmental applications. Low cost and non-invasive chemical sensor arrays provide a suitable technique for in situ monitoring. Their ability and performance under realistic conditions is discussed in this paper. Published studies report promising results despite a number of limitations that are associated with both the technology itself and its application in ever changing ambient conditions. Early investigations include the analysis of single substances as well as odour and wastewater organic load monitoring. Reported applications typically highlight the sensitivity of the currently available sensors to changes in temperature, humidity and flow rate. Two types of approaches are recommended to deal with these effects: either working under fixed experimental conditions or measuring the external parameters to numerically compensate for their change. The main challenge associated with the use of non-specific sensor arrays lies in establishing a relationship between the measured multivariate signals and the standards metrics that are traditionally used for quality assessment of gas mixtures. For instance, odour monitoring requires calibration against olfactometric measurements while investigations of wastewater samples still need to be correlated with organic pollution parameters such as BOD, COD or TOC. On the other hand, results obtained in the field have demonstrated how sensor arrays can be readily used as simple alarm devices or as early warning systems based on a general air/water quality index. [less ▲]

Applying the electronic nose in the environment : requirements for the sensors

Conference (2002, September)

For few years, the department "Environmental monitoring" at FUL applies the principle of the electronic nose equipped with tin oxide sensors to recognise and to monitor real life malodours in the ... [more ▼]

For few years, the department "Environmental monitoring" at FUL applies the principle of the electronic nose equipped with tin oxide sensors to recognise and to monitor real life malodours in the environment and directly in the field. <br />For such emissions, the gas mixtures are very complex and only their odour should be of interest, and not their chemical composition. <br />Moreover, working in the field implies various constraints. <br />The obstacles of the monitoring of real life environmental odours with an electronic nose can be classified into three main areas : the final goal of the study (measuring an odorous annoyance), the analysed sample itself (influenced by the evolution of the process and of ambient parameters) and the operating conditions (necessity to transport the reference gas and the batteries in the field, influence of air humidity). <br />The paper describes the approach of FUL to the problem with various tests conducted in the field with home-made electronic noses based on tin oxide sensors and with very simple configurations. The conclusions, which can be extrapolated to any other sensor types, are promising, but the sensor performances (sensibility, reproducibility, electrical consumption, drift, etc.) should still be improved before reaching the final goal. [less ▲]

Campagne de mesure des odeurs sur le CET "Champ de Beaumont" à Monceau-sur-Sambre Estimation des nuisances olfactives Jacques NICOLAS – Anne-Sophie CHAPLAIN F.U.L. Arlon 12 Août

Report (2002)

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The research group applied a field inspection ... [more ▼]

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The research group applied a field inspection technique based on the perception of a panel of experts sniffing the air around the region of interest and trying to delineate the odour plume. In a second step, the recorded meteorological data are entered into an atmospheric dispersion model and the odour emission rate of the facility is adjusted until the predicted odour impact zone fits about exactly the one which is measured in the field. The present report concerns the site of Monceau-sur-Sambre. [less ▲]

Etude comparative entre les différentes méthodes d'estimation de la distance minimum d'implantation pour des bâtiments d'élevage par rapport aux zones d'habitat et aux habitations isolées

Report (2002)

La première partie de l'étude est une recherche bibliographique sur les différentes formules de calcul de la distance maximale d'acceptation de l'odeur d'élevage entre les bâtiments de la ferme et les ... [more ▼]

La première partie de l'étude est une recherche bibliographique sur les différentes formules de calcul de la distance maximale d'acceptation de l'odeur d'élevage entre les bâtiments de la ferme et les habitations les plus proches. Neuf méthodes ont été particulièrement étudiées (France, Allemagne, Hollance, Québec, Autriche, Suisse, Flandre, ...) et détaillées. Elles ont été appliquées et comparées sur deux études de cas. [less ▲]