Reverse-flow type, for measurement of kinematic viscosity of dark Newtonian liquids according to ASTM D 445 and ISO 3104. Permit measurements of liquids whose meniscus cannot be seen at the timing marks when using a Cannon-Fenske Routine type viscometer. These tubes are not calibrated. Requires minimum sample volume of 12mL. Used to measure kinematic viscosity of liquid (cutback) asphalts and road oils at 60°C (140°F) in range of 30 to 6000 centistokes according to ASTM D 2170. Also used to study lubricating oils at low temperatures when investigating the effect of various additives on lubricating and hydraulic oils. External pressure can be applied to vary shear stress and shear rate. Specifications conform to ASTM D 446 and ISO 3105.