Particle moisture content in fluidized beds can be determined rapidly and continuously by means of a new device for particle collection. Without such equipment determination of the particle moisture content is almost impossible. However, knowledge of the particle moisture content is of central importance for optimum control of the drying process. The moisture measurement system DWF-MA-15 determines particle moisture content rapidly and continuously in fluidised bed processes. An integrated measurement chamber generates a quiescent particle layer whose moisture content can be determined on a real-time basis with a high frequency sensor independent of variation and regardless of process parameters, particle size, particle density and particle form.