Dynamic viscometers - different types of heads

Measuring heads for dynamic instruments comes in various shapes, the most common one being the concentric cylinder type (a), also called bob-and-cup type. The concentric cylinder head normally operates in the shear rate range 0 to 1,000 s^-1.

Significantly higher shear rates can be obtained in various combinations of cones and plates, the most common ones being the cone-plate type (b) and the plate-plate type (e).

Simpler viscometers often work with so-called dip-in geometries (f) with the drawback of not being able to establish a defined and uniform shear field. Hence these types of viscometers cannot be used for absolute measurements on Non-Newtonian fluids.

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