We currently have two rheometers at our disposal, a Fann Model 35A Viscometer and a Rheometrics Pressure Rheometer (RPR). The Fann Model 35A Viscometer was donated to our lab by Halliburton in October 2004. The RPR belongs to Dr. John Dorgan's group at CSM, which was donated by Shell.

The Fann Model 35A Viscometer (pictured left) utilizes a couette geometer (two concentric cylinders). For concentrated solutions a Fanning Yield Stress Adapater can be added. Our viscometer is a six-speed model, with test speeds of 600, 300, 200, 100, 6 and 3 rpm available. Any test speed can be selected without stopping rotation. The shear stress is displayed continuously on the calibrated scale, so that time-dependent viscosity characteristics can be observed. The Model 35A is powered by a 60-Hz motor.

The RPR is currently undergoing maitence to revive it to it's previous operational status. The RRP also utilizes a couette geometry. We currently posses three different sizes of bobs and one continuous float bob. The RPR is capable of conducting dynamic or steady shear tests. The dynamic tests include: single, rate sweep, temperature sweep, frequency/temperature sweep, time sweep, step strain, and continuous square waves. The steady tests include: single, rate sweep, time sweep thixotropic loop, and step rate. Tests can be programmed to run sequentially or separated by shear, time, or temperature. Torque is measured by the torque transducer and bath temperature is controlled by a recirculating oil bath.