The Viscometer of the lifting liquid type here reported is, theoretically similar to the usual falling sphere viscometer, in that both viscometers are based on Stokes' law. The merit of the former viscometer is that the viscosity measurement can be carried out at any desired velocity.
This viscometer is composed of a spherical steel ball hung on an arm of a balance and a vessel which can be drawn-up with a desired constant velocity. The liquid to be examined is put in the vessel and the steel ball is immersed in the liquid.
The apparent mass of the steel ball in the liquid depends on the lifting velocity of the vessel with the liquid in it. By measuring the decrease of the apparent mass of the ball, the viscous drag ƒ acting on the ball is determined. The coefficient of viscosity η can then be obtained from Stokes' law.
The results of experiments show that the coefficient of viscosity thus calculated by Stokes' law depends on the lifting velocity, and its limiting value when the velocity becomes zero is the true value of the coefficient of viscosity.
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