What is rotating concentric cylinder viscometer?

Answer 1

this unit basically consist of two concentric cylinders and a small intervening annular space contains the test fluids whose viscosity is to be determined.The outer cylinder is rotated at a constant angular speed. the viscous drag due to the liquid between the cylinders produce a torque on the inner cylinder, which would rotate if it was not restrained by an equal and opposite torque developed by torsion wire. as the spring torque is proportional to the angle through which it turns, therefor the angular moment of the pointer on a fixed disk is used as a measure of viscosity.