The electrical stability (ES) of an oil-based drilling fluid is a property related to its emulsion stability and oil wetting ability. The Emulsion Stability Tester determines ES by applying a precision voltage-ramped sinusoidal signal across a pair of parallel flat plate electrodes that are immersed in the fluid.
Features include API recommended sinewave circuitry, push button automatic voltage ramping at a fixed ramp rate, meter, probe electrode, calibration standards, and four 9-volt alkaline batteries. Symmetry of the sinusoidal signal inhibits the buildup of solids on the electrode faces and enhances reproducibility.