Viscosity measurements of liquid toluene at low temperatures using a dual vibrating-wire technique

A recently developed dual vibrating-wire technique has been used to perform viscosity measurements of liquid toluene in the temperature range 213 K less than or equal to T less than or equal to 298 K, and at pressures up to approximately 20 MPa. The results were obtained by operating the vibrating-wire sensor in both forced and free decay modes. The estimated precision of the viscosity measurements, in either mode of operation, is +/- 0.5%, for temperatures above or equal to 273 K, increasing with decreasing temperature up to +/- 1% at 213 K. The corresponding overall uncertainty is estimated to be within +/- 1% and +/- 1.5%, respectively.