Patent ID: 8499619

Claim:
A rotary rheometer, comprising: positioning elements; measuring elements; a rack with a positioning unit for positioning said positioning elements, said positioning elements being adjustably supported relative to one another and carrying said measuring elements being capable of being rotated relative to one another and limiting a height of a measuring gap; a normal-force sensor for ascertaining normal-force values generated in a medium sample in a shear test; an evaluating unit coupled to said normal-force sensor and receiving the normal-force values, said evaluating unit having a memory unit containing in stored form a calibrating function ΔS=f(N F ) describing a functional dependence between a gradually performed change of a spacing between said positioning elements and a normal force arising thereby in each case, said evaluating unit having a computing unit for generating control data corresponding to a respective variable of the normal force-values measured; a measuring unit selected from the group consisting of displacement-measuring units and spacing-measuring units for determining a mutual spacing of said positioning elements; and at least one actuator being driven by said evaluating unit and connected to said memory unit for a transfer of a control-signal data, said actuator operating substantially in a delay-free manner and applies force to at least one of said measuring elements one of directly and indirectly.