In most cases the analysis of an odour in ambient air is complex because it is composed of mixed substances. Those substances taken individually are difficult and costly to measure because often their concentrations are low. The method described in the guideline evaluate an odorant in ambient air directly by use of human smell by measuring the percentage odour time (time fraction during one measurement duration when an odour is recognizable) and possibly the odour intensity (in a scale from 0 – no odour to 6 – extremely strong. VDI 3882 Part 1). Measurements are done over a period of 1 year or 6 months by a panel of assessors presenting certain characteristics (details about the panel selection are given in the publication). In the area where an emission occur an assessment area is defined according to the objective of the study. To evaluate the odour situation of this area, a grid is defined and cover the assessment area. Every corners of the grid squares become measurement points where one measurement of at least 10 minutes duration will be done at least 26 times a year. The field inspection methods will depend on the objectives aimed. The analyzed results of this whole procedure give information about the odour dispersion, odour plume and can be used for the validation of dispersion models and draw odour maps.

This guideline gives complete information about the determination of odorants in ambient air by field inspections. The procedures are well presented however no information where available about the reproducibility of the results. This test gives information about odour and other investigation should be done if the odorant composition has to be done to determine the presence of certain gases.