KegelPlatte

KegelPlatte is the term used in German-language rheology to refer to a cone-plate viscometer or cone-plate geometry used to measure the viscosity and flow behavior of liquids. The setup consists of a precisely machined conical element that sits in close proximity to a flat plate, creating a thin converging gap. The sample is placed on the plate, the cone is rotated at controlled speeds, and the resulting torque is measured. Because the shear rate is essentially uniform across the sample, the cone-plate arrangement provides direct viscosity measurements and can accommodate non-Newtonian fluids. Variants include different cone angles (typically 1-4 degrees) and gap settings that tailor the shear rate range. Materials are usually stainless steel or ceramics to withstand temperature control and corrosive samples.

In practice, KegelPlatte devices are used in polymer science, coatings, food products, cosmetics, and research to characterize viscosity as a function of shear rate and temperature. They support steady-state viscometry and rheological tests such as thixotropy and yield stress measurements with appropriate fixtures and seals. Calibration against standard liquids and temperature control are critical for accuracy.

History and nomenclature: the cone-plate geometry emerged in the early era of rheology as a standard rotational viscometer design. In German-language literature the term KegelPlatte reflects the cone-and-plate configuration. See also cone-plate viscometer, rotational viscometer, rheology.