Current Status of Thermodynamic Properties of Hydrogen

This article presents a survey of the thermodynamic properties of normal hydrogen and parahydrogen and gives comparisons of properties calculated from the standardmodels to available experimental data. Motivated by the fact that the currently accepted standards for the thermodynamic properties of hydrogen were based on experimental and correlation work completed before the mid-1980s, an assessment of the accuracy of property values for analysis and design of new systems at high and low temperatures and pressures is provided. Property values measured and published after the completion of the current standards for both normal hydrogen and parahydrogen are included in the comparisons. Recommendations for newexperimental data needed and for newthermodynamic property formulations for normal hydrogen and parahydrogen are included.