Use viscometers to measure the viscosity of various fluids including adhesives, paints, lubricating oils, varnishes, pastes, gels, syrups, and candy coatings. Technically, viscosity is a measure of a fluid’s resistance to flow, or more precisely, it is the ratio of the force required to overcome internal friction between layers of fluid (shearing stress) to the change in speed between layers of fluid (velocity gradient).
Many quality control measures in food applications, paints, inks, and various other fluids, are based on viscosity as determined by viscometers. Test your knowledge of the definitions below:
What is Absolute Viscosity?
What is Apparent Viscosity?
What is Kinematic Viscosity?
Look for the answers to these definitions and other related terms below.
Newtonian Fluid: Viscosity remains constant with a change in shear rate. Examples: water, paint solvents
Non-Newtonian Fluid: Viscosity varies with a change in temperature, or shear rate. Examples: catsup, batters, inks
Absolute Viscosity: Viscosity of a Newtonian fluid under given conditions. Absolute viscosity = kinematic viscosity x density
Density: Units of specific gravity or g/mL (e.g. poise = stokes x g/mL)
Apparent Viscosity: Viscosity of a non-Newtonian fluid under given conditions
Kinematic Viscosity: Absolute viscosity/density
Poise: Unit of absolute viscosity; abbreviated “p.” Equivalent to stokes x specific gravity. A centipoise is 0.01 p. Poise = g/s x cm
Stoke: Unit of kinematic viscosity; abbreviated “St.” A centistoke is 0.01 St. Stoke = g/s x cm x density (temperature in °F)
See our selection of viscometers.
Be the first to comment on "Viscosity and Viscometers: Test Your Knowledge"