1. Lubrication performance: The lubricating performance of air compressor oil is related to the viscosity of air compressor oil. Generally, there is no viscosity or viscosity reduction, which means that the lubricating properties of the air compressor oil are poor. After the lubricating performance of the air compressor oil is reduced, the adhesion or adhesion also deteriorates accordingly, and an oil film with sufficient strength cannot be formed, and it cannot play a good lubricating effect.
Rub thumb and index finger with air compressor oil, if it feels sticky. It can be concluded that the air compressor oil has good lubricating properties. If it feels astringent, it can be concluded that the air compressor oil has lost its proper lubricating properties.
2. Moisture: Put the air compressor oil into the test tube and observe its transparency. If it is not clear and transparent, but cloudy, it can be preliminarily determined that the air compressor oil contains water.
There are two reliable ways to determine whether an oil contains moisture:
1. Put anhydrous steel sulfate (white powder) into a test tube equipped with air compressor oil. For example, copper sulfate changes from white to blue, proving that there is water in the oil. This method cannot give how much water, and can only be estimated based on the amount of air bubbles and copper sulfate in the heating process of the air compressor oil.
2. Pour the oil to be tested into the test tube, and the amount of oil is two-thirds of the volume of the test tube. After sealing the mouth of the test tube with cork and wax, place it on an alcohol lamp to heat. If there are bubbles and a popping sound, and water droplets are condensed on the wall of the test tube above the oil surface, it means that there is water in the oil.
3. Viscosity: The air compressor oil that meets the quality standard is installed in the test tube, and it is sealed with cork and wax. Do not fill up. Leave about 5mm of space. Install the air compressor oil to be checked in another test tube. The tube used should be of the same size and oil volume as the previous tube and sealed with cork and wax.
Observe the bubbles and test the viscosity:
Invert the two test tubes and observe how fast the bubbles rise. If the air bubbles rise faster than the air bubbles in standard air compressor oil, the oil is less viscous. Instead, the viscosity is high.
4. Impurities: Put the air compressor oil into the test tube and observe whether there are suspended particulate impurities.
