VISCOSITY MEASUREMENT WITH DOUBLE-WIRE TORSION PENDULUM

A new method of measuring the viscosity of liquid, which is named the double-wire torsion pendulum method in contrast to the conventional torsion pendulum method, is described in this paper. It was found that the damping factor alpha(l) changes nearly linearly with the kinematical viscosity eta/rho of the standard oil in the range from 1.55 to 1.15X10(4) cp. An empirical formula is derived for the damping factor alpha(l) and the viscosity eta/rho, and which factors can influence this empirical formula are also presented. The apparatus as constructed is capable of measuring the viscosity and its activation energy over a wide range of temperatures, and is especially suitable for melts at high temperatures with a wide, accurate, dynamic viscosity range. Applying this method, we have observed that the viscous activation energy of a supercooled Li2BBO13 melt is obviously different from that of the normal melt. (C) 1995 American Institute of Physics.