"CNS 3390-2010 Viscosity Test Method for Transparent and Opaque Liquids (Dynamic Viscosity and Absolute Viscosity) " is a standard method for determining the viscosity of liquids. The standard specifies that at a specific temperature, the kinematic viscosity of transparent and opaque liquids is measured by a capillary viscometer, and its dynamic viscosity is calculated. It is suitable for Newtonian fluids, such as petroleum products, lubricating oils, etc. Its core is to use the flow time of liquids in capillaries to determine the viscosity. It is easy to operate and the results are accurate. It provides an important reference for industrial production, quality control and scientific research.