What is the optimum temperature for detecting the viscosity of the lubricant? Should it be 40 ° C or 100 ° C?
Viscosity is the most important indicator of lubricating oil. Whether lubricating oil is suitable for use, first of all, it depends on whether the viscosity is within the required range. If the viscosity is not suitable, then the lubricating oil should not be used, so viscosity is a common testing item for lubricating oil. Viscosity, generally have two tests of kinematic viscosity or absolute viscosity, especially the kinematic viscosity.
Why do you want to determine the temperature for viscosity detection?
To check the viscosity of the lubricant, we select a temperature at which to measure, because the viscosity will change with temperature. The same lubricant, the viscosity measured at different temperatures is not the same. When the temperature rises, the lubricating oil will become thinner and the viscosity will decrease. When the temperature is lowered, the viscosity of the lubricating oil will increase and the oil will become thicker.
Is the viscosity measured, 40 degrees or 100 degrees?
At present, the lubricating oil is generally measured at 40 ° C or 100 ° C, specifically at 40 ° C or 100 ° C, depending on the specific circumstances, is not arbitrarily measured.
The temperature at which the viscosity is measured is preferably close to the temperature at which the equipment is operated. Generally, industrial lubricants detect viscosity at 40 ° C because the operating temperature of industrial equipment is close to this range.
In addition, the change in viscosity of the lubricating oil is relatively more pronounced at low temperatures. Therefore, if you want to detect viscosity changes caused by some abnormal factors, such as water in the lubricating oil, mixing with fuel, viscosity change caused by oxidation, etc., at a low temperature of 40 °C Relatively easier to detect.
However, some devices operate at relatively high temperatures. In order to make the detection temperature close to the operating temperature, we should measure the viscosity at high temperatures, such as automotive engines, which typically measure viscosity at 100 °C.
Calculate the viscosity index of the lubricant:
Some equipment may experience large temperature changes during operation. For this case, we need to measure a high temperature viscosity and a low temperature viscosity. For example, multi-stage oil is used for lubrication where the temperature changes greatly, and multi-stage oil is in two. The temperature is measured separately for viscosity, a high temperature viscosity, and a low temperature viscosity. Through these two viscosities, we can calculate the viscosity index of the lubricating oil. For the case of large temperature changes during operation, the viscosity index of the lubricating oil is an important factor. Index. High viscosity index, indicating that the lubricant is relatively stable in temperature change.
to sum up
When testing the viscosity of a lubricant, you need to figure out these issues:
The temperature at which the device is operating normally.
Is there a large temperature fluctuation (greater than 20-30 °C) during the operation of the equipment?
If the viscosity is to be compared with other oil samples, the measurement conditions (including temperature) should be consistent.
