加速式液体引上げ粘度計

抄録

A theory based on Stokes's law together with the assumption of a quasi-steady state of liquid flow is presented for the determination of the coefficient of viscosity η in a lifting liquid type viscometer. The theoretical work shows that the coefficient of viscosity η^* calculated by Stokes's law depends on the lifting velocity and that its limitting value when the velocity becomes zero is the true value η of the coefficient of viscosity.
The apparatus used in the experiments is composed of a spherical plastic ball hung on one arm of an automatic balance and a vessel which can be lifted with approximately constant acceleration by cylindrical cam mechanism. The liquid to be examined is put in the vessel and the ball is immersed in the liquid. The apparent mass of the plastic 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 agreement between the theoretical and experimental results is generally good and it is recognized that the above mentioned theory provides a basis for the theoretical work in this field.