A rectangular sample under evaluation is made to rotate in a slurry cup. The sample is weighed before and after the test to determine loss of mass due to slurry erosion. Volume loss is computed for comparison, due to difference in densities of materials. Index of erosion is reported as loss of volume.

The test rig permits running up to 6 test samples at the same time and same speed. Slurry cups are immersed in water bath to maintain slurry temperature. Test duration can be preset with timer.