Falling capillary tube viscometer suitable for liquids at high pressure

A new high pressure viscometer based on a falling capillary tube was developed for the study of liquids and solutions. The viscometer was used to determine the viscosity of water containing 4.8 wt % CO₂ at pressures up to 40 MPa and over the temperature range from 273.15 to 323.15 K. Measurements of methanol at 0.1 MPa and water at pressures up to 40 MPa and over the temperature range from 273 to 333 K were used to confirm the accuracy of the new viscometer. For the methanol and water, agreement to within 1.8% of the literature values was found. The new viscometer should be applicable up to 200 MPa as judged by the current apparatus and materials of construction.