Relativní viskozita a absolutní viskozita jsou dva pojmy, které popisují viskozitu tekutiny, a jsou mezi nimi určité rozdíly.

Relativní viskozita:

Relative viscosity refers to the viscosity of a fluid at a certain temperature compared to some reference fluid, obvykle rozpouštědlo. It is determined by measuring the flow properties of the fluid with respect to the reference fluid. Relative viscosity is a dimensionless value that indicates the degree to which the viscosity of the fluid increases with respect to the reference fluid. Relative viscosity can be calculated by measuring the movement time or flow velocity of the fluid.

Relativní viskozita se liší od absolutní viskozity

Absolutní viskozita:

Absolutní viskozita se týká skutečné viskozity kapaliny, také známá jako dynamická viskozita nebo dynamická viskozita. Určuje se měřením objemu (průtok) through which the fluid passes per unit time per unit area. Absolutní viskozita je fyzikální veličina s jednotkami, obvykle se používá v PASCAL sekundách (Pa·s) or millipa ·s (mPa·s).

The absolute viscosity is an intrinsic property of fluid and can be directly used in the calculation and analysis of fluid mechanics. The relative viscosity is the relative value of the reference fluid, which is often used for the measurement of liquid mixtures and the comparison of liquid properties.

North-south tides remind you that the relationship between relative and absolute viscosity can be expressed by a constant, called the constant of proportionality or the conversion factor of relative viscosity to absolute viscosity. Tento konverzní faktor závisí na použité referenční kapalině a teplotních podmínkách. To summarize, the relative viscosity is the fluid viscosity comparison value with respect to the reference fluid, while the absolute viscosity is the actual viscous physical quantity of the fluid.