Three properties of carbon dioxide, namely, pressure, temperature, and entropy, are combined to produce three graphical plots: (1) Pressure vs. Temperature, (2) Entropy vs. Temperature, and (3) Entropy vs. Pressure. These three plots are, in actuality, the three projections of a three-dimensional surface depicting all the phases of carbon dioxide. The fluid must exist on the surface at all times, and any thermodynamic process will occur along the surface. The general configuration of the three dimensional surface for carbon dioxide is shown, and the areas depicting structures are labeled.
Proceedings of the Iowa Academy of Science
©1960 Iowa Academy of Science, Inc.
Boatman, Paul M.
"Three Dimensional Pressure Temperature Entropy Diagram,"
Proceedings of the Iowa Academy of Science, 67(1), 431-436.
Available at: https://scholarworks.uni.edu/pias/vol67/iss1/53