Centrifuge-assisted falling-sphere viscometry

A method for the determination of viscosity using the falling-sphere method adapted to a high-T centrifuge operating at >><$I> 1000 rpm is described. The viscosity can be determined in the range 10 (super 5) to 10 (super 8) Pa s with an accuracy of + or - 0.09 common log units. This method has been used to obtain melt viscosities in a range higher than that attainable by concentric-cylinder methods and lower than that accessible by most dilatometric methods. This improves considerably the experimental description of the T-dependence of the viscosity of silicate liquids.