The purpose of the GOR apparatus is to flash pressurized liquids and measure the gas oil ratio at equilibrium conditions. The liberated gas is measured with the gasometer at ambient conditions while the dead oil flashed is determined by gravity technique. The GOR apparatus features the capability of recirculating the evolved gas back through the on board high pressure oil pycnometer and gas pycnometer. This recirculation ensures vapor liquid equilibrium and allows the operator easy access to representative homogeneous samples of atmospheric pressure vapor and liquids. The establishment of equilibrium is essential for high pressure volatile liquids such as those encountered in reservoir fluid studies.