Viscosity measurement by means of falling spheres compared with capillary viscometry

Modern opto-electronic techniques were combined with the classical falling sphere method of viscosity determination to measure the viscosities of two viscous liquids. Concurrently, in the same temperature controlled environment, the viscosities of the same two liquids were determined in capillary tube viscometers which had their calibration based, via the step-up procedure, on the viscosity of distilled water at 20.00 degrees C. From the results obtained it is shown that the two independent methods agree to 0.5% at 5800 mm 2 s -1 and to 0.6% at 26000 mm 2 s -1 .