PTDiagrammen
PTDiagrammen, short for pressure–temperature diagrams, are graphical representations of the phase behavior of a substance in pressure–temperature (P–T) space. In a PT diagram, pressure is plotted against temperature, and phase boundaries separate regions where the substance exists as a solid, liquid, or gas. Points on a boundary indicate a two-phase equilibrium; the triple point is where solid, liquid, and gas coexist, while the critical point marks the end of the liquid–gas boundary.
PT diagrams are constructed from thermodynamic data and phase-transition models, often using the Clapeyron equation to
Beyond simple two-dimensional diagrams, PT diagrams can be extended to multicomponent systems (PT–x diagrams) that include