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Viscosity Index (VI)
An arbitrary scale used to show the magnitude of viscosity changes in lubricating oils with changes in temperature. Oils with low viscosity index(VI) number such as VI=0(zero) have high dependence of viscosity change on temperature. They thicken quickly with decreasing temperature, and thin out quickly ...
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Kinematic Viscosity
Absolute viscosity of a fluid divided by its density at the same temperature of measurement. It is the measure of a fluid's resistance to flow under gravity, as determined by test method ASTM D445. To determine kinematic viscosity, a fixed volume of the test fluid is allowed to flow through a calibrated ...
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Apparent Viscosity
The ratio of shear stress to rate of shear of a non-Newtonian fluid such as lubricating grease, or a multi-grade oil, calculated from Poiseuille's equation and measured in poises. The apparent viscosity changes with changing rates of shear and temperature and must, therefore, be reported as the value ...
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Absolute viscosity
The ratio of shear stress to shear rate.It is a fluid's internal resistance to flow. The common unit of absolute viscosity is Poise and CentiPoise(cP). Absolute viscosity divided by the fluid's density equals kinematic viscosity. Absolute viscosity is typically measured by a rotary viscometers to determine ...
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Viscosity - General Introduction
The measure of the internal friction or the resistance to flow a liquid.Low viscosity fluids flow easily, for example, water;High viscosity fluids pour slowly, for instance, molasses.Measurement of a fluid's resistance to flow. The common metric unit of absolute viscosity is the poise, which is defined ...
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Cold Cranking Simulator (CCS)
The cold-cranking simulator (CCS) was designed as a method of determining the low temperature performance of lubricants, in the specific condition of "cold cranking" - i.e. starting a cold engine. In this condition, the only energy available to turn the engine comes from the starter motor and the battery, ...
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Introduction of Acid Number Test of Insulating Oil
To maintain the acid number within specified level is the key of quality control of the insulating oil. Acid number is expressed by potassium hydroxide in mg required to neutralize free fatty acid in 1g of oil.Measurement of acid number of insulating oil is specified in some test standards, such as GB7599 ...
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References of Acid number of insulating oil
1) GB7599 and GB/T 264 Test Methods for Acid Number in Operational Transformer Oil and Turbine Oil2) JIS-C2101-1999 Test Method for Electrical Insulating Oil3) JPI-5S-57-99 Japan Petroleum Institute - Neutralization Test Method for Electrical Insulating Oil - Total Acid Number Indicator Photometric Titration4) ...
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Cautions in measurement of acid number of insulating oil
1) The indicator of alkali blue 6B is hard to dissolve in ethanol, and needs to be stirred more than 2 hours before titration;2) The indicator is liable to change, and recommended to use withiin 2 days after prepared;3) Be aware the accuracy of measurement depends on the correct amount of indicator when ...
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Bingham Plastic Fluids
Bingham Plastic Fluids have a yield value which must be exceeded before it will start to flow like a fluid. From that point the viscosity will decrease with increase of agitation. Toothpaste, mayonnaise and tomato catsup are examples of such products.
