Viscosity Measurements of n-Dodecane at Temperatures between 303 K and 693 K and Pressures up to 10 MPa

The dynamic viscosities of n-dodecane were measured at temperatures between 303.3 and 693.3 K and pressures up to 10.0 MPa using a dual-capillary viscometer. The accuracy of the dual-capillary viscometer was improved by considering centrifugal effects and the thermal expansion of the capillary. The combined relative standard uncertainty in the dynamic viscosity was calculated to be 0.58–2.92 %. This study provides new data to check the accuracy of Huber’s correlations at supercritical pressures, and a small proportion of the data points at supercritical conditions where few experimental data have been reported. The average absolute deviation between the experimental data and the calculated data from Huber’s correlations is 0.97%, and the maximum absolute deviation is 6.79%. In the near-critical and supercritical region, the accuracy of viscosities of n-dodecane needs more experimental data for verification and to extend the theories.