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scaled equation of state parameters for gases in the critical regionIn the light of recent theoretical developments, the paper presents an accurate characterization of anomalous thermodynamic behavior of xenon, helium 4, helium 3, carbon dioxide, steam and oxygen in the critical region. This behavior is associated with long range fluctuations in the system and the physical properties depend primarily on a single variable, namely, the correlation length. A description of the thermodynamic behavior of fluids in terms of scaling laws is formulated, and the two successfully used scaled equations of state (NBS equation and Linear Model parametric equation) are compared. Methods for fitting both equations to experimental equation of state data are developed and formulated, and the optimum fit for each of the two scaled equations of the above gases are presented and the results are compared. By extending the experimental data for the above one-component fluids to partially miscible binary liquids, superfluid liquid helium, ferromagnets and solids exhibiting order-disorder transitions, the principle of universality is concluded. Finally by using this principle, the critical regions for nine additional fluids are described.
Document ID
Document Type
Reprint (Version printed in journal)
Sengers, J. M. H. L.
(National Bureau of Standards, Institute for Basic Standards, Washington D.C., United States)
Greer, W. L.
(Maryland, University College Park, Md., United States)
Sengers, J. V.
(Maryland, University College Park, Md.; National Bureau of Standards, Institute for Basic Standards, Washington, D.C., United States)
Date Acquired
August 8, 2013
Publication Date
January 1, 1976
Publication Information
Publication: Journal of Physical and Chemical Reference Data
Volume: 5
Issue: 1, 19
Subject Category
Funding Number(s)
Distribution Limits