This paper describes a new photosedimentation device that monitors and measures the settling rate, hindered settling constant, flocculation factor, sediment volume and rate of coagulation of monodisperse samples of solid particulates in dispersant liquids. First we examine the well-known theoretical aspects of sedimentation as well as some sedimentation and turbidity applications. Then we introduce the K200 photosedimentometer and most of its technical features and advantages with respect to existing devices. Finally, we give the results of several turbidimetric (particle size modification, concentration determination) and settling measurements (stability parameters).