μPa·s

micropascal second

Dynamic viscosityexact by definition

The micropascal second is 10⁻⁶ Pa·s, exact by prefix, and equal to 0.01 centipoise. It is the viscosity scale of gases: air at 20 °C is 18.2 μPa·s, hydrogen 8.8, and carbon dioxide 14.7.

Watch out: Gas viscosity rises with temperature while liquid viscosity falls, which surprises people the first time and is a consequence of gas viscosity being about molecular transit between layers rather than about intermolecular attraction.

1 μPa·s 0.000001 Pa·s