Odour emission is as much a part of the adverse effect of any new or existing process as noise, water pollution, VOC emissions or radiation. It is essential to quantify ii whenever plans are being made for new or modified processes. The first aspect of quantification of odour emission is the need to use a standard method of measurement of odour concentration. As with liquid effluents where we use standard laboratory methods for each characteristic, e.g. BOD, GOD, TSS etc., the analysis method for measurement of odour concentration is the CEN/TC264/wg2 (draftprEN13725) standard (ComitteEuropeen de Normalisation/Technical committee 264/Working Group 2). This standard is often specified in tender documents as the methodology to be used in the assessment of abatement equipment performance. In this paper the standard, with what it can and can not do, is described in detail. The second aspect is that methodologies should be agreed for sample collection. The collection protocol, at the lowest level, is agreed so that significant day to day comparisons can be made. More rigorous protocols must be drawn up when legal requirements need to be met so there is consistent enforcement of regulations or discharge consents. It is most important that a representative odour sample is collected from the source. This is most problematic when the odour is emitted from a large surface either with or without airflow through it. Best practice methods are presented and discussed. The Statistical significance of the analysis, as with any other measurement, depends upon the precision of the laboratory analysis and the number of samples analysed. An example will be used to illustrate the importance of calculating the number of samples required for a given purpose. [References: 9]
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