Absolute Temperature Scale between 4.2° and 5.2°K

Abstract
The vapor pressure of helium has been determined between 4.25° and 5.1°K, using a constant volume gas thermometer. An equation is proposed which fits the experimental data closely, and gives temperatures which differ by a maximum of 0.02° from the currently accepted values. The reliability of the value of the boiling point of helium and the thermodynamic consistency of the properties of liquid helium near the boiling point are discussed.