In order to determine product moisture content in fluidised beds, a special collection device was constructed. The NaWiTec (junior research group for fluidised bed technology) of the Otto-von-Guericke university of Magdeburg is engaged with the study of particle formation processes in fluidised beds. Particle formation in fluidised beds is an important aspect in the area of granulate technology. Fully automatic control and regulation of these processes with regard to the material properties of the granulate has been hardly possible up to now. Often the granulation process can only be influenced by the many years of experience of the plant staff by selective modification of process parameters in such a way that a granulate material with the desired properties is produced. Disturbances or fluctuations in the process are often not recognised, which cause corresponding changes in product quality.