Viscometer Design Gravity is used © To generate a Torque (shear stress) And the angular Velocity (shear rate) is Measured Schematie diagram of the 1912 Searle controlled- stress,concentric-cylinder viscometer(D.Hopkins). Controlled Stress Rheometer Optical Encoder Air Bearing、 Induction Sample- Temperature Control Apply shear stress as a torque with the induction motor And measure the shear rate from the angular velocity Important things about viscometers Calibration ·Artifacts ·Wall effects ·Evaporation* Sedimentation/separation ·Chemical attack Mechanical damage ·Sampling ·High-speed testing* 公2 ·Suspended particles 99 Viscometer Design Gravity is used To generate a Torque (shear stress) And the angular Velocity (shear rate) is Measured Optical Encoder Air Bearing Induction Motor Sample Temperature Control Controlled Stress Rheometer Apply shear stress as a torque with the induction motor And measure the shear rate from the angular velocity Important things about viscometers • Calibration • Artifacts • Wall effects* • Evaporation* • Sedimentation/separation • Chemical attack • Mechanical damage • Sampling • High-speed testing* • Suspended particles