This test method details the standard procedure for plotting viscosity-temperature charts that ascertain the kinematic viscosity of a petroleum oil or liquid hydrocarbon at any temperature within a limited range, provided that the kinematic viscosities at two temperatures are known.

1.1 This practice covers kinematic viscosity-temperature charts (see Figs. 1 and 2), which are a convenient means to ascertain the kinematic viscosity of a petroleum oil or liquid hydrocarbon at any temperature within a limited range, provided that the kinematic viscosities at two temperatures are known.

1.2 The charts are designed to permit petroleum oil kinematic viscosity-temperature data to plot as a straight line. The charts here presented provide a significant improvement in linearity over the charts previously available under Method D341–43. This increases the reliability of extrapolation to higher temperatures.

1.3 The values provided in SI units are to be regarded as standard. The values given in parentheses are provided for information only.