Vacuum pumps are used in many industrial and scientific processes including composite plastic moulding processes, production of most types of electric lamps, vacuum tubes, and CRTs where the device is either left evacuated or re-filled with a specific gas or gas mixture, semiconductor processing, notably ion implantation, dry etch and PVD, ALD, PECVD and CVD deposition and so on in photolithography, electron microscopy, medical processes that require suction, uranium enrichment, medical applications such as radiotherapy, radiosurgery and radiopharmacy, analytical instrumentation to analyse gas, liquid, solid, surface and bio materials, mass spectrometers to create a high vacuum between the ion source and the detector, vacuum coating on glass, metal and plastics for decoration, for durability and for energy saving, such as low-emissivity glass, hard coating for engine components (as in Formula One), ophthalmic coating, milking machines and other equipment in dairy sheds, vacuum impregnation of porous products such as wood or electric motor windings, air conditioning service (removing all contaminants from the system before charging with refrigerant), trash compactor, vacuum engineering, sewage systems (see EN1091:1997 standards), freeze drying, and fusion research. In the field of oil regeneration and re-refining, vacuum pumps create a low vacuum for oil dehydration and a high vacuum for oil purification. Especially in the field of transformer maintenance, vacuum pumps play an essential role in transformer oil purification plants which are used to extend the lifetime of transformers in the field.