The effect of temperature on viscosity The most widely-used expression is that due to Andrade log10 n =A+B/T where T is the temperature in degrees absolute (C+273.15),i.e.K.Note that this equation is also known by other names for instance the Arrhenius law where B is replaced by E/R where E is an activation energy for viscous flow and R is the universal gas constant.The activation energy E is said to be a measure of the height of a potential energy barrier associated with the force needed to produce elemental quantum steps in the movement of molecules. Arrhenius 4 exp FkThe effect of temperature on viscosity Arrhenius   A exp Ea RT      