For measuring kinematic viscosity of transparent Newtonian liquids, particularly petroleum products or lubricants, according to ASTM D 445 and ISO 3104. These tubes are factory calibrated. Specifications conform to ASTM D 446 and ISO 3105. Approximately 7 mL of sample is needed. If you are measuring liquids whose meniscus cannot be seen at the timing marks, use the Cannon-Fenske Opaque type viscometer.