Choosing the right measuring system
Modern rotational rheometers are capable of measuring the rheological properties of a wide variety of materials, from low viscosity fluids such as milk, through to high modulus solids such as asphalt and hard plastic stips. This versatility is largely due to the range of torques and angular displacements that can be accessed on such instruments, although the choice of measuring system or geometry is of critical importance also. Common geometries include cone and plate, parallel plate or cup and bob systems, along with a number of less common configurations which come in different sizes and surface finishes depending on the sample type, measurement range and application of interest.
Philip Rolfe, Technical Specialist provides an overview of the various geometries available for rotational rheometers and their advantages and disadvantages for different sample types and applications.