A method for estimating the vapor-liquid equilibria of binary liquid solutions using an Accelerating Rate Calorimeter (ARC) is described. ARC provided data in the ranges: (0–14) kPa and (300–450) K. The experimental PTx data were reduced to partial pressures and vapor phase compositions using Barker's method. The well-known system, benzene/cyclopentane, was selected to evaluate the ARC method. GC-headspace analysis confirmed the vapor phase compositions. Both GC and ARC data on the vapor phase agree with literature data to within ±0.0085 mol fraction units. Experimental pressure data agree with literature data to within ±2 kPa. Model pressure data agree with literature data to within ±1.5 kPa. Also described is the high-pressure VLE of the phosgene-chlorobenzene binary at 448 K.