(1) Visual measurement: Normal human vision is usually about 40um. Therefore, when the particle size of impurities in the oil is greater than 40um, the human eye can see it. When the visual inspection can directly observe the pollutant, it is clear that the oil at work is now very dirty and needs to be replaced.
(2) Test tube test: use the test tube to compare the new oil with the applied oil. If the color of the applied oil appears black, it needs to be replaced. If the color does not change and becomes cloudy, clarify that the oil is rich in water. After clearing away the water, the oil can be used continuously. Such as light color and no odor, can be mixed with heterogeneous oil, only the appropriate viscosity, can also continue to use.
(3) Filter paper detection: take a drop of oil heated and put it next to the experimental filter paper, and make it drop down. If there are solid impurities, the filter paper will remain thin and black mottled, which illustrates that the oil contains more impurities and should not be used continuously.
(4) Heating test: To find out whether the oil is rich in water, heat an iron plate to about 250℃ and drop a drop of oil on the iron plate. If there is a cracking sound, clarify the water content. Oil without moisture is burned silently.
On 2018-08-08 11:45:46
