On an Experiment of a Falling Ball Viscometer for Opaque Solution

A falling ball viscometer which can be used availably for viscous and particularly opaque solution as well has been tested. Two several turns coils independent on each other are set up instead of visible marks round the viscometer tube filled with solution of unknown viscosity. The coils form respectively electric oscilator circuits of different radio frequencies. Falling down a small metal ball in the solution, the inetant when it passes through the coil is to be detected by means of measuring or watching the voltage of heterodyne beat produced by two electric oscilations, of which frequencies deviate alternately by passing of the metal ball, and out-put voltage in question dips consequently owing to the band pass filter. Some considerations for suitable choice of every part and its dimension, namely diameters of ball and coils, frequencies applied etc., which effects to sensitivity and stability, are also given. Result obtained shows that the system is applicable effectively for measuring viscosity of various kinds of solution, for example, dull viscous solution (contains Titanium dioxide), pastes of pigment dyestuff, printing inks, paints, and so on.