Simple methods for testing lubricating oil

Visual inspection:

Visual inspection of the appearance of lubricating oil is the simplest detection method, which can help us find obvious contaminants or impurities, and can also initially detect whether the oil has been oxidized and deteriorated.

Testing method: Take a slender, dry, clean, transparent container (such as a clean oil sampling bottle) and pour a certain amount of lubricating oil into it. If it is new oil, the oil should be transparent, shiny and free of impurities. If it is opaque or even turbid, white, suspended or precipitated, it should be suspected that the oil is contaminated or has quality problems, and it should be further passed through the laboratory. detection.

Sediment detection:

If a visual inspection reveals sediment in the oil, you can identify the sediment through the following simple methods. Take some oil samples and put them in a clean, dry white container. The material of the container cannot be porous. You can use a plastic bottle or porcelain. Put the oil in it, cover it, and let it sit for two days. Pour out the oil after two days, but leave the few milliliters at the bottom because if there is sediment, it will settle to the bottom. Observe the remaining oil at the bottom. If sediment is found, it means there are contaminants in the oil, because impurities as large as 40 microns can be seen with the naked eye. Magnets are used to attract these impurities. If they can be attracted, it means they are usually fine abrasive particles such as iron filings. If it is not attracted by the magnet, but it feels grainy when you rub it with your fingers, it is probably sand. If you find that the oil is stratified or even whitened after standing, it is probably due to moisture.

Smell:

Take a portion of the new oil and the in-use oil respectively, and smell the smell of the lubricating oil. The smell of the in-use oil in normal condition should be the same as that of the new oil. If there is a burnt smell, sour smell, rancid smell or other pungent smell, , indicating that the oil has deteriorated. When conducting odor inspection, visual inspection should also be combined. Normal lubricating oil should not only have a normal smell, but also have a normal appearance and transparency.