Mud Balance Tester Used to determine density of the drilling fluid. The instrument consists of a constant volume cup with a lever arm and rider calibrated to read directly the density of the fluid in ppg (water 8.33), pcf (water 62.4), specific gravity (water = 1.0) and pressure gradient in psi/1000 ft. (water 433 psi/1000 ft.) Calibration • Remove the lid from the cup, and completely fill the cup with water. • Replace the lid and wipe dry. • Replace the balance arm on the base with knife-edge r