Oil testing--the significance of viscosity
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Firstly, in oil testing, we generally measure the dynamic viscosity at 40°C and/or the dynamic viscosity at 100°C. This is because the grade of most oils is determined based on the viscosity value at 40°C; for example, gear oil with a grade of 320# means that its dynamic viscosity at 40°C is 320. The grades of engine oils, on the other hand, are usually determined at 100°C. The acceptable range of variation for dynamic viscosity is plus or minus 10%; by testing this parameter, we can determine whether the oil is of satisfactory quality and whether it can continue to provide lubrication for the equipment. If the measured value of dynamic viscosity deviates significantly from the specified value, we can conclude that it is possible that the wrong oil was used. Using the wrong type of oil can cause serious damage to equipment; for example, if a lower-grade oil is used, the oil film may not be able to withstand mechanical stresses, leading to dry friction within the equipment! If a higher-grade oil is used by mistake, the potential harm may be less severe than that caused by using a lower-grade oil; however, it will lead to increased lubrication resistance, higher power consumption, and device overheating. In devices that require high precision, this can affect the accuracy of their performance!
The correct term should be: dynamic viscosity. However, viscosity is difficult to write, and its meaning is quite similar to that of kinematic viscosity; therefore, for simplicity, it is often replaced by “kinematic viscosity”! When conducting tests, we often use the method number to identify the correct testing method, as the method number is unique!
Kinematic viscosity can also be used to determine whether water has entered the lubricant
No, science demands rigor! Let the data speak! To check for water intrusion, we can directly measure the moisture content