Odours immissions are determined using olfactometric tests based on VDI guideline 3940 and GIRL that are carrying out by volunteers in the vicinity of existing plants. There is a distinction between the grid and plume inspections.
Grid inspections are generally used to determine the pre-load condition in the environment of facilities and equipment that are planned, or are to be modified, and as acceptance testing to verify compliance with the ancillary provisions of pollution legislation. The method yields a statement about the extent of existing odours under defined conditions. In addition to the frequency of odours, and odour intensity, hedonic tones may also be determined in the field.
Plume inspections are mainly used to determine the emission and/or propagation characteristics of emission sources. The plume dispersion of emission sources are determined by means of flags, dispersion models are validated or calibrated, and evaluations of odour emissions from emissions sources are made in conjunction with a dispersion model.
Müller-BBM is a Germany notified measuring bodies for the determination of odour emissions.