Vacuum environments created for engineering applications

Vacuum today plays an increasing part in the engineering and scientific fields. It is used for many purposes in industry and scientific research, from single vacuum forming of domestic utensils and assisting in applying brakes in cars and trains, to the complex requirements of the semiconductor industry and the reduced molecular density required for nuclear particle accelerators. The pressure range encompasses 15 orders of magnitude at the present time. This paper endeavours to describe the basic behaviour of gases in this field, the production and measurement of vacuum, and some of the applications and systems used