"What is the optimal testing temperature when testing the viscosity of a lubricant? Should it be 40 degrees or 100 degrees?" Viscosity is the most important indicator of a lubricant, and whether a lubricant is suitable for use depends first on whether the viscosity is in the required range. If the viscosity is not suitable, then the lubricant should not be used, so viscosity is a common test item for lubricants. When testing viscosity, there are generally two kinds of testing: kinematic viscosity or absolute viscosity, with kinematic viscosity being the most common.

  1. Why do viscosity tests need to determine temperature?

  To test the viscosity of a lubricant, we select a temperature and measure it at that temperature, because the viscosity changes with the temperature. The same lubricant, measured at different temperatures viscosity is not the same. As the temperature increases, the lubricant becomes thinner and the viscosity decreases. When the temperature decreases, the viscosity of the lubricant increases and the oil thickens.

  2, testing viscosity, 40 degrees or 100 degrees?

  At present, lubricating oil is generally measured viscosity at 40℃ or 100℃, specifically at 40℃ or 100℃, depending on the specific situation, and is not arbitrarily measured.

  Regarding the measurement temperature of viscosity, it is better to be close to the temperature of equipment operation. Generally speaking, industrial lubricants are tested for viscosity at 40°C because the operating temperature of industrial equipment is relatively close to this range.

  In addition, changes in the viscosity of lubricants are more significant at low temperatures, so if you want to detect changes in viscosity caused by abnormal factors, such as water in the lubricant, mixed fuel, oxidation, etc., it is relatively easy to detect them at 40°C.

  However, the operating temperature of some equipment is relatively high, so in order to make the testing temperature close to the use temperature, we should test the viscosity at high temperature, such as automobile engine, generally at 100℃ to test the viscosity.