INTER-LABORATORY MEASUREMENTS OF THE VISCOUS PROPERTIES OF NEWTONIAN AND NON-NEWTONIAN FLUIDS WITH THE FALLING NEEDLE VISCOMETER

Six Laboratories performed independent measurements of the viscous properties of Newtonian and Non-Newtonian Fluids using Falling Needle Viscometers. University, Governmental and Industrial laboratories were represented. Although the fluid samples measured by all the laboratories were identical, no investigator knew the property values in advance. Each investigator made measurements on three Standard Newtonian fluids and three paint products which were pseudoplastic non-Newtonian fluids. Results are presented showing that the Newtonian viscosity measurements agreed within ±1% with the standard values and the non-Newtonian flow curves within ± 10%.