Abstract: The invention relates to a method of determining the transport behaviour in the pneumatic transport of granular materials, in which (A) the sample of granular material is introduced into a feed chute, (B) the sample of granular material is, after the feed chute, introduced via an injector into a regulated stream of air, (C) the sample of granular material flows through a transport section and (D) the sample of granular material is measured in a laser light scattering spectrometer, wherein in step (B) the sample of granular material is introduced via a Venturi injector. The apparatus for carrying out the method comprises a feed chute for introduction of granular materials into the transport section, a feed chute for introduction of unstressed granular materials into the laser light scattering spectrometer, an air flow regulating valve, a Venturi injector, a transport section and a laser light scattering spectrometer (4).