An interactive program was written to simulate pressure-volume-temperature (PVT) experiments using a microcomputer. The simulator is a real time representation of an actual PVT laboratory. Operations that may be performed in the laboratory may also be performed on the simulator. The Peng-Robinson equation of state is used to calculate phase behavior and the results of the calculations are displayed on the microcomputer monitor in color. The monitor represents graphically the condition of all of the physical components of the PVT lab including pressures, fluid levels in vessels and the status of valves and pumps. A printed record of every action taken during a run is kept if desired. A simulated experimental error results in an appropriate termination of the run. Program structure and operation are described, and examples of simulated PVT experiments are given.