Principle : a rheometer is a device for measuring the rheological properties of materials. rheology is defined as the study of the flow and the deformation of the material describing the interrelation between forces, deformation and time.
in contrast to a viscometer, which can only measure the viscosity of a fluid under certain conditions, a rheometer is capable of measuring the viscosity and elasticity of materials are non-newtonian in a variety of conditions.
the rhéomètres rotational mixing are without doubt the tools that rheological the most versatile available, and they can be configured in a number of methods rheological different to detect the structure and performance of the suspensions.
the samples are placed between two plans, or other geometries that are similar, such as a cone and a plan or a system of duvet. the application of a torque to the upper plane exerts a shear stress rotation on the material, and the deformation or rate of deformation resulting (velocity gradient) is measured. the rhéomètres rotational and viscometers share the same principle of operation, but the first have features much better. this is blatant when it comes to the accuracy and the range at which the shear stress can be applied, or even to their practicality to the test oscillatory and their level of control on the applied normal force during testing rotational mixing.