Test Method for Aniline Point of Engine Oil
Engine oil, also known as engine lubricating oil, is a binary lubricant composed of base oil and additives, with a chemical formula of mixture. Its density is approximately 0.91×10³ kg/m³. Under normal temperature and pressure conditions, it is a clear amber or dark brown liquid, featuring low-temperature operability, excellent viscosity-temperature properties, oxidation resistance and foam resistance. It is commonly used in the maintenance of various types of engines, playing the roles of lubrication and anti-wear, auxiliary cooling and temperature reduction, sealing and leak prevention, rust and corrosion prevention, as well as shock absorption and buffering.
Purpose of the Experiment：
In the fields of chemistry and scientific research, the determination of the aniline point of engine oil helps to assess its environmental risks; reflect the composition and purity of the oil product, and assist in judging whether the oil product complies with relevant standards and specifications; guide the selection and application of the product; evaluate its compatibility with aromatic hydrocarbon substances and high-temperature stability, so as to prevent the oil product from precipitating sediments or reacting with rubber seals during actual use, which may affect operational safety.
The experiment is carried out in accordance with the GB/T 262 standard. The SD262B Automatic Aniline Point Tester manufactured by Shengtai Instruments complies with this standard and is selected for the experiment.
Experimental Instruments & Samples
①SD262B Automatic Aniline Point Tester
②Auxiliary items including test tubes, aniline, sodium sulfate for industrial use, n-heptane, cleaning solvents, etc.
Testing method：
①Inspect components such as the temperature sensor and photoelectric detector, and perform necessary adjustments and calibrations.
②Select the test mode according to the sample properties and set the expected temperature range.
③Inject the sample into the sample tube, avoiding bubble formation or overflow.
④Start the test; the instrument will automatically complete heating, stirring, cooling and endpoint determination with full-process intelligent control.
⑤After the test is completed, the instrument displays and stores the aniline point temperature value, and supports printing or data export.
Experimental Results：
Through multiple experimental tests and analyses, the aniline point of this engine oil is greater than 85°C, which complies with the standard.