VDI 3940 Blatt 1:2006-02

The present guideline is a set of instructions for the measurement of odour impact in an assessment area. The odour load is measured in this case by qualified assessors who assess the ambient air for odours at previously defined locations within certain measurement cycles. Grid measurement is a statistical survey method in which over a certain period, e.g. six months, assessors record detected odours at grid intersection points in the assessment area in accordance with a certain methodology. The results are used for calculating the odour impact characteristic (number of hours per year of odour impact) for the assessment squares in the assessment area. Such grid measurements make it possible to ascertain the existent odour load caused by sources outside and inside the assessment area. In Germany grid measurements are mainly employed in approval and monitoring proceedings and in urban development planning as a means of determining the prior or total odour load in the assessment area.