The Gas Dosing Unit (GDU) improve the efficiency of laboratory operation by integrating existing peripherical devices (e.g. autoclaves or high pressure vessels) to the standard or tailor-made dosing systems. The automated pressure controlling systems of GDU-STATIC-series are used to generate static atmospheres in connected volumes. Pressurization as well as depressurization occurs by means of two high-pressure dosing valves in pulsed-width controlled operation. The gas dosing system of GDU-DYNAMIC-series controls fluid flow conditions as well as system pressure.