Viscosity of CHF3 in the Critical Region

The gaseous visosity of trifluoromethane (CHF3) was measured in the critical region. The experimental temperature range was between 299.150 and 303.150 K and the pressure range was up to 5.66 MPa. The measurements were obtained with an oscillating-disk viscometer, combined with local determination of the density at the position of the oscillating disk, and they have an estimated accuracy of 0.6% for the viscosity and 0.5% for the gas density. The viscosity of CHF3 exhibits an anomalous increase near the critical point. The anomalous increase in viscosity was analyzed with the viscosity equation proposed by Basu and Sengers.