Fluid Measurements

Viscometer

According to the definition of viscosity or Dynamic Viscosity, it can be determined by the shear stress and the rate of shear strain. By using a rotating motion instead of linear motion to the fluid viscosity testing experiment, a continuous motion can be applied.

Consider two concentric cylinders with a small gap in between and the velocity distribution of the fluid is linear.

Therefore, the viscosity can be determined by measuring the torque at a specified angular velocity.