A test to determine the volume percent of solids in a mud that are retained on 200-mesh screen. A glass, sand-content tube with a tapered lower end and a 200-mesh screen are used in the test. The test measures percent solids above 74 micrometers, which include those that could be abrasive to pumps and piping. When performed according to the API protocol for water-base muds, the sand-content tube is filled to the first mark with mud. Water is added to the next mark and the tube is shaken. The diluted slurry is poured through the 200-mesh screen, discarding the liquid. The screen is washed and the residue on the screen is poured back into the tube. Volume percent "sand" is measured from divisions on the tapered tube.