Determination Method for Evaporation Loss of Engine Oil

Determination Method for Evaporation Loss of Engine Oil

Engine oil, also known as engine lubricating oil, is a binary lubricant composed of base oil and additives. It is a mixture with a chemical formula, a density of approximately 0.91×10³ (kg/m³), and appears as a clear amber or dark brown liquid under normal temperature and pressure conditions. It features low-temperature operability, viscosity-temperature performance, oxidation resistance, and anti-foaming properties. It is commonly used for the maintenance of various types of engines, serving functions such as lubrication and wear reduction, auxiliary cooling and temperature reduction, sealing and leak prevention, rust and corrosion prevention, and shock absorption and buffering.

Experimental Purpose

In the field of chemical scientific research, the evaporation loss test is of great significance for lubricating oils. This test can evaluate the high-temperature stability and heat resistance of oil products by simulating actual high-temperature working conditions to determine their volatility tendency, and judge their ability to maintain physical and chemical properties under long-term high temperatures; predict service life and maintenance cycles, optimize oil change intervals, and reduce the risk of equipment shutdown due to insufficient lubrication; optimize product formulas, provide data support, and assist researchers in adjusting the ratio of additives to base oil to improve the overall performance of lubricating oils.

Experimental Instruments

① SH0059B LCD Color Screen Lubricating Oil Evaporation Loss Tester

② Auxiliary components such as an analytical balance with a sensitivity of 0.01g, a thermometer, a Y-shaped glass tube, and cleaning agents

Experimental Procedures

① Inspect the instruments required for the experiment to ensure they are clean, dry, and free of contamination.

② Extract 65±0.1g of a representative sample into an empty crucible, weigh the crucible without a lid, and record the weight accurately to 0.01g.

③ Check the temperature of the heating element, place the crucible into the hole seat, and ensure that the flanges under the two screws on the heating element can overcome the buoyancy of the Wood's metal.

④ Turn on the power, start the stopwatch and vacuum pump, and adjust the evacuation valve to a reading of 20mm±0.2mm.

⑤ After the experiment runs for 60min±5s, turn off the vacuum pump, remove the crucible, quickly remove all attached alloy, and immerse the crucible in warm water at least 30mm deep for 30min.

⑥ Take out the crucible, wipe the outer wall dry, remove the crucible lid, and reweigh the crucible without the lid, accurate to 0.01g.

⑦ Calculate the results and repeat the experiment 1 to 3 times.

Experimental Results

Through experiment and analysis, the evaporation loss of the engine oil at 250℃ for 1 hour is 8.77%, which is lower than the value specified in the standard and meets the requirements.