AMOUNT-OF-SUBSTANCE DENSITY OF CO2 AT TEMPERATURES FROM 329 K TO 698 K AND PRESSURES UP TO 34 MPA

New measurements of the amount-of-substance density of pure gaseous CO 2 in the temperature range 329 K to 698 K at pressures from 3 MPa to 3 4 MPa are reported. The results have been obtained by using a fully au tomated isochoric instrument and their average uncertainty is estimate d to be about +/-0.05 per cent at the lowest temperatures, rising to /-0.1 per cent at the highest temperatures. Comparisons with the predi ctions of the recent empirical equation of state of Span and Wagner, a s well as with earlier experimental results, which the present work co mplements, are included. It is shown that the equation of Span and Wag ner is probably more accurate than was originally estimated at high te mperatures and pressures.