The Model 280 is a hand-powered, two-speed rotational Rheometer designed specifically for field testing the rheological properties of drilling fluids. A small crank drives the rotor at a pre-selected constant speed through a precision gear train governor. Rotor speeds of 300 or 600 are obtained by setting the position of the speed control lever. Measurements are read directly from the deflection scale. The readings obtained are used to determine the plastic viscosity and yield point of the test fluid.
Gel strength measurements are read directly from the deflection scale. When making gel-strength measurements, force is applied manually by turning the gel knob and observing the maximum