A new mass-detecting capillary viscometer

The mass-detecting technique has been applied to design a capillary viscome ter for viscosity measurements of both Newtonian and non-Newtonian fluids o ver a range of shear rates. Flow-rate and pressure-drop measurements are re placed with a measurement of liquid-mass variation with time. Using a preci sion balance, one can measure the variation of fluid mass collected in the receptacle, m(t), from which the test fluid viscosity and shear rate are ma thematically calculated. The feasibility and accuracy of the mass-detecting technique have been demonstrated for water and non-Newtonian fluids by com paring results against established viscosity measurement techniques. The ad vantages of this design are simplicity (i.e., ease of operation and no movi ng parts), low cost, and the ability to measure viscosity over a relatively broad range of shear rates. (C) 2001 American Institute of Physics.