Viscometers: Measurement of critical physical property
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Posted On :
Dec-07-2011
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Article Word Count :
782
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Viscometers measure viscosity fluid flow or stress resistance. General terms, viscous fluid "thickness
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Viscometers measure viscosity fluid flow or stress resistance. General terms, viscous fluid "thickness" a strong interest in physical property liquids, slurries and pastes manufacturers. Viscosity is an important feature of the food (eg, milk, honey, syrup, soft drinks), paints, cleaners, adhesives, polymers, oil, and pharmacy. Many industry-viscosity liquid products to produce an end.
Dozens of types of viscometer is in academia, industry and basic research, and use this cost from about $ 100 a simple mechanical viscometers $ 15,000 range of automated tools. Rheometers, which measure the viscosity and related properties, can cost as much as $ 200,000.
At the lower price range is the U-tube and cannon-tube viscometers Fenski find schools, colleges, and some industries. Another simple design, with the area covered by the piston, rolling the ball, and the oscillating piston viscometers. This is not the truest sense of the demands pourable liquids.
Complex used in the processing industry, the vibrational and rotational viscometers viscometers. The latter works on the principle that energy must be applied to the blade spindle rotates through the fluid to overcome the fluid resistance. That energy is proportional to the fluid viscosity. Rotational viscometers require that the test sample pourable. For example, the toothpaste can not be tested in a tube viscometer, because he does not "run", but the significant results can be obtained using a paddle or cylinder-type viscometers.
Upper class viscometers can be connected and controlled via computer, or readings can be taken directly to the front panel display. Some industries benefit type viscometer. Dyes and pigments industry chooses Stormer viscometer, which uses the paddles on the rotor is immersed in the product. In addition, the laboratory uses a resin bubble viscometers, which is the length of the bubble out of the lakes, the oil companies prefer Stabinger viscometer, which employs a rotating cylindrical tube.
Viscometry is an old method, as shown by the mechanical durability of viscometers. But while manufacturers continue to finetune more complex electromechanical rotational viscometers, the basic technology has not changed much.
What is different, "says Steven ATS RheoSystems Colo (Bordentown, NJ), president of user experience. "Twenty years ago, most consumers academic specialization or viscometry rheology. Today the Dingo professionals and consumers are likely to be cooperating.
P. Colo Review changes in consumer demographics as an opportunity to provide support and expertise to the operation, sample testing and data interpretation.
What to tell the viscosity
Biotechnology and pharmaceuticals, proteins, and buffer viscosity is one of a number of quality checks, drinks, sugar content and viscosity of the overall performance index. Polymer scientists have used the plastic viscosity of acid concentration.
Viscosity measurements are usually carried out in dilute solutions of various concentrations. Different strengths of polymer solutions viscosity measurements, for example, provides estimates of secondary properties such as intrinsic viscosity-molecular weight and chain length.
Viscosity is related to solute concentration, which is what makes one of the most useful physical measurements, research and product development. Liquid viscosity generally increased levels of particulate Solutes in water with sugar. But completely miscible and nonreacting liquid mixture viscosity is usually somewhere between the components of the viscosity.
Rheometers
Rheometers are closely associated with viscometers, that they measure the viscosity and yield stress. Viscometers when the fluid "thickness" according to native conditions, rheometers to assess the application of shear stress or function. In addition to viscosity, rheometers measures modulus, shear modulus, tan delta, the gel point and curing profiles.
Rheology of complex fluids tend to learn mechanics, that can not be entirely specific to the viscosity. Darren Wilson, Product Specialist, Anton Paar (Ashland, VA) associated with these materials as "non-Newtonian, ie, the viscosity changes in different shear rates.
"Most of the examples of Newton, which means it does not matter if you are using a viscometer or Rheometer. But the viscosity is not to tell the full story at the Newtonian fluids, such as ketchup, mayonnaise, shampoos, and many types of paints and coatings."
Purchasing decisions
Useful viscometer / Rheometer features that buyers should be aware of the temperature control of spindle rotation speed control, sample holders, and ease of use. Temperature is very important - notes Mr. Colo., as the viscosity of the liquid flow is usually cool. Shaft can also affect the viscosity.
Mr. Wilson notes that the sample size may be a problem when the very expensive materials, such as drug or protein analysis, as highvolume programs, cost of ownership. Another factor is a measure of measurement range. "If you analyze, from crude oil, petroleum naphtha, or want to change each measurement, the capillary or use something that works all the way?
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Article Source :
http://www.articleseen.com/Article_Viscometers: Measurement of critical physical property_115489.aspx
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Author Resource :
Visit viscometer.co for all types of viscometer according to your need.
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Keywords :
viscometer, digital viscometer,
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