Abstract: An apparatus for measuring the sedimentation characteristics of particulate solids in liquid is disclosed. The apparatus comprises two separate vertical housings adapted to be filled to the same level with a liquid less dense than the particulate solids to be measured, means for introducing a sample of particulate solids to be measured in one of the housings, two pressure sensors located at the same level, one in each housing, and a differential pressure transducer connected to such pressure sensors for sensing the differential pressure caused by the sample introduced into one of the housings. The differential pressure transducer provides an output indicative of the weight percent of sample remaining in suspension as a function of time and such output may be used to determine the weight fraction of the particulate solids passing any given mesh size, or for measuring the specific gravity of particulate material of known dry weight.