milliPascalseconds

Millipascalseconds, abbreviated as millipascal-seconds and written as mPa·s, are a unit of dynamic viscosity equal to one thousandth of a pascal-second (0.001 Pa·s). They are a subunit of the SI-derived unit pascal-second (Pa·s) and are convenient for describing the flow resistance of liquids with relatively low viscosities. The millipascal-second is widely used in practical measurements, even though it is not an independent SI base unit.

In relation to other viscosity units, 1 mPa·s equals 1 centipoise (cP). Since 1 Pa·s equals 1000 mPa·s, the millipascal-second forms a direct bridge between the SI unit Pa·s and the more traditional cP, facilitating comparisons across systems. The dimension of mPa·s is that of pressure multiplied by time, reflecting its origin as a measure of resistance to shear flow rather than a simple unit of time.

Common usage and examples: the viscosity of water at room temperature is about 1.0 mPa·s. Many liquids span from a few mPa·s to thousands of mPa·s; for instance, glycerol at room temperature is around 1500 mPa·s (1.5 Pa·s). This scale allows easy reporting of viscosity values in contexts such as chemistry, materials science, and engineering.

Measurement typically employs viscometers, including capillary and rotational types, with temperature control being essential for meaningful comparisons. See also Pa·s, centipoise, Poise, viscosity, and rheology for related concepts.