DIN 51562-2-1988 Viscosimetry; Determination of kinematic viscosity with a U-Viscosity meter; Trace U-Viscosity meter is a standard developed by the German Institute for Standardization, which specifies the method of measuring the kinematic viscosity of liquids using a miniature Ubbelohde Viscosity meter. The standard applies to the measurement of kinematic viscosity in the range of 0.35800 mm ²/s for liquids with a Measuring temperature range of 10 ° C to 100 ° C. It includes the structural design of the Viscosity meter, measurement procedures, Sample Handling, equipment calibrating and evaluation of results. Measurement accuracy is achieved by calibrating capillary tubing of different diameters to cover a wider viscosity range. The standard provides a scientific basis for viscosity measurement in laboratories and industrial production, and is widely used in petroleum, chemical and materials science.