Millipascalisekunti

Millipascalisekunti, abbreviated mPa·s, is the SI-derived unit of dynamic viscosity. It expresses how much a liquid resists shearing under an applied force. By definition, 1 millipascalsekunti equals one thousandth of a pascal-second (1 mPa·s = 0.001 Pa·s). The dynamic viscosity of a liquid is typically low for water and higher for viscous liquids like syrups or oils.

Relation to other units is straightforward: 1 Pa·s = 1000 mPa·s, and 1 mPa·s equals 1 centipoise (cP) in common practice, since 1 cP = 0.001 Pa·s. In engineering and chemistry, mPa·s is the most convenient unit for measuring liquid viscosity at standard temperatures.

Measurement methods include capillary viscometers, such as Ubbelohde devices, and rotational viscometers, including cone-plate or parallel-plate configurations. Temperature strongly influences viscosity: as temperature rises, viscosity generally falls. This dependence is crucial in processes like lubrication, polymer processing, and fluid transport.

Typical values illustrate the range: water at room temperature is about 1 mPa·s, whereas light oils may range from tens to hundreds of mPa·s, and honey or glycerol can reach thousands of mPa·s. For highly viscous fluids, larger units such as Pa·s or even kPa·s are used.

See also: dynamic viscosity, kinematic viscosity, poise, centipoise, viscosity measurement methods.