the measurements of the vapor-liquid coexistence curve in the critical region for R 114 (C
2CL
2F
4) were made by visual observation of the disappearance of the meniscus at the vapor-liquid interface within an optical cell. Twenty-three saturated densities between 410 K and critical temperature were obtained in the range of densities 290 to 894 kg/m
3. The experimental errors of temperature and density were estimated within ±0.5%, respectively. On the basis of there results, the critical temperature T
c and the critical density ρ
c for R114 were determined to be 418.78 K and 576 kg/m
3, respectively, in consideration of the disappearing meniscus level as well as the intensity of the critical opalescence. The critical pressure p
c for R114 was calculated to be 3.252 Mpa by the available vapor-pressure correlation with the present value of T
c. In addition, the critical exponent β and the low of rectilinear diameter near the critical point were also discussed.
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