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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.
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Dilatant Fluids
Shear Thickening Fluids or Dilatant Fluids increase their viscosity with agitation. Some of these liquids can become almost solid within a pump or pipe line. With agitation, cream becomes butter and Candy compounds, clay slurries and similar and similar heavily filled liquids do the same thing.
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Thixotropic Fluids
Shear Thinning Fluids or Thixotropic Fluids reduce their viscosity as agitation or pressure is increased at a constant temperature. ketchup and mayonnaise are examples of thixotropic materials. They appear thick or viscous but are possible to pump quite easily.
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Newtonian Fluids
Fluids for which the shearing stress is linearly related to the rate of shearing strain are designated as Newtonian Fluids.Newtonian materials are referred to as true liquids since their viscosity or consistency is not affected by shear such as agitation or pumping at a constant temperature. Fortunately ...