The model VLE 110 is designed for operation under atmospheric, vacuum or at overpressure up to 3 bars absolute with a charge volume of approx. 35 mL and temperatures of up to 250°C. A special electrical immersion heater, made of quartz-sand material is located in the central bottom part of the glass apparatus effecting evaporation. The reflux circulation streams are intensely stirred in a mixing chamber which ensures a quick adjustment of the equilibrium. Sample take-off of both phases (liquid and vapour) can be realized either by an automatically controlled valve plungers via solenoid valves or can alternatively be taken from the circulation streams via a gas-tight syringe which is also part of the delivery. An additional sampling port offers the possibility to take gaseous samples of the vapour phase which is a special advantage for mixtures with miscibility gaps. The system is delivered with a micro processor based control device for precise and reliable work.