The determined odour intensity and hedonic odour tone may be useful for the planning of emission reduction measures, especially if limit values are exceeded. By comparing "before" and "after" measurements, it is possible to ascertain whether and to what extent a change has been achieved in the facility's surroundings. Options for appropriate applications to determine and assess odour intensity and hedonic odour tone in the field are explained. Instructions and examples of use of the methods described in the standards VDI 3940 Part 3 and Part 4 are given.