TATA Steel in IJmuiden is a fully integrated steel plant situated on the North Sea about 30 kilometres northwest of Amsterdam, the Netherlands. The production route from raw materials to steel coils and slabs comprises various processes including by-product manufacturing, and can be divided in three main sections. In the first section, raw materials are converted in thermal processes into agglomerates, from which hot liquid metal (pig iron) is produced. In the second section, liquid metal is purified in a steel plant and casted into slabs, or into coils in a direct sheet. In the third and final section, the steel slabs and coils are processed in a hot and cold mill and result in coils that finally are galvanised and/or painted for various market sectors, e.g. automotive, construction, packaging and consumer goods. The TATA Steel plant is located in a densely populated area, and has to comply with strict environmental regulations. Emissions from TATA Steel may lead to complaints about odour, dust and noise from residential areas. Since about 60% of the annual complaints are related to odour nuisance, TATA Steel is forced by the regulating authorities in the Netherlands to investigate the various odour sources and their contribution to nuisance. The project was executed in co-operation with Comon Invent and VITO. Comon Invent has developed an online eNose technology for the evaluation of odour plumes in the field. The Flemish Institute for Technological Research, VITO, is an acknowledged institute for olfactometry. In 2010 a research project was started at TATA Steel IJmuiden to explore the opportunities of online eNoses. The first phase of the program comprised a three-month field trial with a network of five eNoses aiming at the detection of passing plumes and a thorough investigation of the odour emission from the most dominant odour emission sources, which was performed according to the European standard EN 13725. During the sampling and in the laboratory testing the eNose signals were analysed against the ...