Abstract: An apparatus for measuring density of drilling mud. An elongated cylindrical measuring chamber is pivoted on a base at one end and includes conduits for introducing the mud into the chamber. A force measuring thrust a gauge mounted on the base and supporting the chamber intermediate its ends provides a signal proportional to the weight of the receptacle and its contents. Since the volume of the chamber is constant the weight varies as a function of the density of mud. A rotating wire brush mounted within the chamber tends to scrape away accumulating solid material on the inner walls thereof. The chamber is provided with a ceramic liner.