Although very often cited in publications dealing with food products, electronic noses still pose metrology problems. Lack of reproducibility is one of the more crucial problems, prohibiting any on-line quality control measurement based on an aroma reference previously taken. The database drift is due either to the intrinsic drift of the sensor or to the variations of experimental conditions. In order to quantify the influence of these conditions on the sensor performance, three screening experimental designs are performed on standard solutions, containing wine off-flavour volatiles. Three parameters are studied: the head-space temperature, the measurement cell temperature and the way of injecting samples. Their influence on indexes representing repeatability and discrimination allows the determination of the best experimental set-up.