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 αl changes nearly linearly with the kinematical viscosity η/ρ of the standard oil in the range from 1.55 to 1.15×104 cp. An empirical formula is derived for the damping factor αl and the viscosity η/ρ, 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 Li2B8O13 melt is obviously different from that of the normal melt.