EFFECT OF REFLECTED WAVE FROM THE WALL OF A VESSEL AND END EFFECT OF THE PLATE IN THE OSCILLATING-PLATE METHOD

The effect of reflected wave and the end effect of a new oscillating-plate viscometer, constructed by Sasahara et al., have been investigated experimentally over a wide range of viscosity. The results obtained are as follows: (1) The resonant frequencies of the plate oscillations in liquid samples decrease with increasing rhomu values. However, the viscosity dependence of the resonant frequency is negligibly small when an adequate leaf-spring is used for chinning the plate attached to stem. (2) The effect of reflected wave from the wall of a vessel is negligible when the distance between the plate and the wall is kept over one wavelength of the wave produced by the plate oscillations. (3) The end effect of the oscillating-plate increases with increasing not only the thickness of the plates but also the viscosity of liquids. (4) The working formula for viscosity determination by the oscillating-plate method should be corrected by considering the above two effects.