Vapor-liquid equilibrium measurements using the PTx method have been made on three binary mixtures: difluoromethane/hydrogen chloride, cis-1,3-dichloropropene/trans-1,3-dichloropropene, and pyrrole/water. Each binary mixture was studied at two temperatures. Equilibrium vapor and liquid-phase compositions were derived from the PTx data using the Soave-Redlich-Xwong equation of state to represent the vapor phase and the NRTL activity coefficient model to represent the liquid phase. The pyrrole/water system exhibited a region of immiscibility at the lower temperature at which it was studied. Karl Fischer titration was used to determine the compositions of the equilibrium liquid phases.