Determination of the Real Critical Pressure and Critical Density of Substances

The phase diagram of the pure substance ( is visually plotted on the P-T phase diagram based on pressure and temperature dependent experimental results. In the phase diagram, all three phases are present and the triple point where these phases are in equilibrium. In addition, a point on a liquid-gas equilibrium curve, commonly known as a critical point is also available on the phase diagram . In the classical P-T phase diagram used today, only shows the three phase and boundary curves that separate these phases from each other, the triple point where the three phases are at one point and the critical parameters where the liquid gas equilibrium curve ends (Tcr, Pcr, ρcr).