The density of hydrogen fluoride at high pressures to 973 K and 200 MPa

High pressure-high temperature equipment and procedure is described to dete rmine the density of hydrogen fluoride as a function of pressure and temper ature. An autoclave constisting of a nickel-based superalloy and a suitable pressure sensitive separator between hydrogen fluoride and the pressure tr ansmitting fluid is used. Eleven isochors between 0.210 and 0.824 g cm(-3) at temperatures between 473 and 973 K and at pressures between 20 and 200 M Pa have been determined. Previous literature data extend to 30 MPa and 573 K. Polynomials with six terms are used to represent nine isotherms from 573 to 973 K with a maximum average deviation of 0.1%, A table with smoothed d ensity values is presented for the whole range of conditions. Isothermal sp ecific volume data are reasonably well presented by Tait equations. Paramet ers are given. (C) 1999 Elsevier Science B.V. All rights reserved.