The purpose of this article is to update the common knowledge on characteri
stic features of empirical multiparameter equations of state, to increase t
he confidence of potential users, and possibly to attract other scientists
to theoretical and experimental work that is relevant for the future develo
pment of these kinds of thermodynamic property models. To do so, the most i
mportant features of current multiparameter equations of state and of the a
lgorithms which are used to develop such formulations are briefly explained
. Future challenges are outlined with regard both to the development of mul
tiparameter equations of state and to the underlying experimental basis. Re
levant references are. given for further studies. (C) 2001 Elsevier Science
B.V. All rights reserved.