A fundamental property of a fluid that characterizes its resistance to flow and shear. Expressed in pascal-seconds (Pa.s) or mPa.s. A highly viscous fluid (honey: ~10 Pa.s) flows slowly, while a low-viscosity fluid (water: 0.001 Pa.s) flows quickly. Viscosity varies with temperature, shear rate, and time, hence the need to use a rheometer rather than a simple viscometer for a complete characterization.
« Back to Glossary Index