The indicators detected in the lubricating oil testing instrument include viscosity, kinematic viscosity, flash point, acid value, moisture, mechanical impurities, oxidation stability, etc.
(1) Viscosity: Reflects the internal friction of the oil, and is an indicator of the oiliness and fluidity of the oil. Without adding any functional additives, the higher the viscosity, the higher the oil film strength and the worse the fluidity.
(2) Kinematic viscosity: the ratio of the dynamic viscosity of the fluid to the density ρ of the fluid at the same temperature. The unit is (m^2)/s. It is represented by a lowercase letter v. Note: The unit used in the past is St (s) cSt (Ris) and the rate relationship of (m^2)/s is: 1(m^2)/s=10^4St(s)=10^6cSt( Cents).
(3) Flash point: Under specified conditions, heating the lubricating oil, when the oil temperature reaches a certain temperature, the mixture of the lubricating oil's steam and the surrounding air has been in contact with the flame, that is, flashing occurs. This is the lowest The flash temperature is called the flash point of the lubricating oil.
(4) Acid value: the quality index to determine the total content of organic acids in lubricating oil, and the number of milligrams of potassium hydroxide needed to neutralize the acid in 1 gram of lubricating oil.
(5) Moisture: refers to the percentage of water content in the lubricating oil, usually a percentage by weight. The presence of moisture in the lubricating oil will destroy the oil film formed by the lubricating oil, make the lubricating effect worse, accelerate the corrosive effect of organic acids on metals, rust the equipment, and make the oil prone to sedimentation.
(6) Mechanical impurities: refer to the precipitates or colloidal suspensions in the lubricating oil that are insoluble in solvents such as gasoline, ethanol and benzene. Most of these impurities are sand, gravel and iron filings, as well as some organic metal salts that are difficult to dissolve in solvents brought by additives. Generally, the mechanical impurities of lubricating base oil are controlled below 0.005%.
(7) Oxidation stability: It shows the anti-aging performance of lubricating oil. There are many methods to determine the oxidation stability of oil. Basically, a certain amount of oil is in the presence of air (or oxygen) and a metal catalyst. Oxidize at a certain temperature for a certain period of time, and then measure the acid value, viscosity change and the formation of precipitates of the oil. Oxidation stability is the ability to inhibit the formation of substances that are not conducive to the use of oil.
