Viscosity-Temperature Correlation for Liquids

A new viscosity-temperature equation and corresponding chart have been developed to extend the range of the current ASTM viscosity-temperature charts. This new chart and equation extends the temperature and viscosity range for hydrocarbons and, for the first time, has the ability to extend to the low viscosity regime of halocarbons and low temperature fluids. The new equation and chart can linearize liquid viscosity data from 0.04 cSt and covers the temperature range from −210°C to 500°C for halocarbons and hydrocarbons. With a modification to the temperature scaling, the new equation also has the ability to fit liquid metal viscosity data. The new chart and equation cannot accurately linearize the viscosity with respect to temperature of fluids exhibiting strong molecular bonding (water, ammonia), fluids whose molecular structure consists of long coils (some long chained silicones), or fluid mixtures in which one fluid precipitates out of solution (wax precipitation).