Apparatus for converting a rotary viscometer for determining elastic properties of a viscoelastic substance

摘要

In a rotary viscometer, the viscosity of a viscoelastic substance in a measuring beaker (20) is determined from the reaction torque acting on a bob (25), held lowered in the beaker, while the beaker is rotated at a constant speed by the frictional coupling between that beaker and a drivable shaft (15), in a recess (16) of which the beaker is mounted. By means of a drive converting mechanism (50) the viscometer can be adapted for determining the elastic properties of the viscoelastic substance by operatively connecting a connecting rod (70) of the drive converting mechanism to the measuring beaker (20), the mechanism (50) converting the continuous rotary drive of the shaft (15) into to-and-fro angular rotation of the beaker (20) within the recess (16). The required elasticity measurement can be derived from the difference in phase angle between the instantaneous angular position of the beaker and the instantaneous reaction torque acting on the bob (25). IMAGE