Bulb Correction in Capillary Tube Viscometry

Abstract

IN a recent letter¹ Mr. A. C. Merrington points out that, when a material for which the viscosity decreases greatly with increase in rate of shear is investigated in a capillary viscometer, the resistance offered by the bulbs is a greater fraction of that offered by the capillary than when a true fluid is tested in the same apparatus. He thinks it possible that in some cases where anomalies have been reported in the relationship of flow-rate to capillary radius, the results can be completely accounted for by neglect of the bulb correction. He also thinks that in other instances it has influenced the results without being the whole cause of the observed anomalies.