Kayvan Sadeghy - Associate Professor Department of Mechanical Engineering, Universityof Tehran

An innovative concentric-cylinder viscometer was designed and fabricated capable of measuring viscosity of both Newtonian and non-Newtonian fluids over a wide range of viscosities and shear rates. The instrument was designed based on Gerrman DIN53018 and DIN53019 standards. It features several innovative design concepts in order to make its price competetive with commercial viscometers. The use of a hollow torsion bar of high bending stiffness virtually eliminated the need for an air bearing thus reducing the overall price and maintenance cost. The design also allows the torsion bar to be replaced quite easily with a new one of arbitary shape and material thus making the instrument equally good for both ”thin” and ”thick” fluids. A highly-sensitive torque transducer based on a LVDT sensor was designed and incorporated in the viscometer for accurate torque measurements. A novel alignment mechanism significantly reduced the time and effort needed for aligning the two concentric cylinders (one stationary and the other rotating).

Couette Viscometer, Torsion Bar, Viscosity, Non-Newtonian Fluids