A Viscometer of the Lifting Liquid Type (III)

Abstract

This viscometer is composed of two balls of equal diameter and equal mass, which are hung on the two arms of a balance whose ratio of arms L_B and L_A is ν. The liquid to be measured is put in two vessels, in which the balls are immersed. Each vessel is drawn up with desired constant velocities of υ_A and υ_B, such that their ratio becomes υ_B/υ_A=n=_??_.
By adjusting a counter weight W, hung on the arm at the position of L from the fulcrum, the balance is brought into equilibrium.
Let the weight W at υ_A=υ_B=0 be W₀, the difference ΔW of the weights W₀ and W, gives the viscosity η by the equation η=n/1-n•1/6πr•L/L_A•ΔWg/υ_A, assuming Stokes' law of viscosity.
Moreover, the viscosity η can be obtained independently of the lifting velocity, provided that the lifting velocity is small.
The results of experiments show that the true value of the viscosity is obtainable by direct indication.