scope:

Guideline VDI 4285 describes procedures for the measurement of emissions from diffuse sources. In the sense of this guideline, diffuse sources are all those sources that do not belong to conducted sources. The waste gas stream is not conducted in a channel and therefore, the emissions cannot be measured on the basis of the guidelines VDI 2066 Part 1 [T3] or VDI 4200 [T25].

The determination of emissions from diffuse sources, as described in guideline VDI 4285, is based on the determination of measurands such as substance concentrations and meteorological parameters and is combined, where appropriate, with a calculation model. Measurements at diffuse sources are carried out in the interface to the atmosphere or after the pollutants to be measured have entered the atmosphere.

While guideline VDI 3790 [T21; T22] describes diffuse sources and possibilities to estimate the emissions and control them, the present guideline deals with the determination of diffusive emissions by measurements.