Measurement verification procedure approved by the National Technical Supervision Bureau on March 4, 1991 and implemented on September 1, 1991, is applicable to the verification of newly manufactured, neutralized and repaired Eng's Viscosity meters. The Eng's Viscosity meter calculates kinematic viscosity by measuring the time it takes for a liquid to flow out of a specific volume. The specification specifies the technical requirements of the Viscosity meter, such as the standard water value should be (51 +/- 1) seconds, the inner wall of the cup body and the outflow pipe should be smooth and scratch-free, etc.; it clarifies the verification conditions, verification items and methods, including Appearance inspection, standard water value measurement, etc.; and specifies the verification result processing and verification period (half a year). This procedure provides a guarantee for the accuracy and Reliability of the Eng's Viscosity meter and is widely used in petroleum, chemical and other fields.