The pneumatic air leak test is used for integral leak testing with positive or negative pressure and for flow measurement with gaseous test media, usually with air, but not for leak detection. For this purpose, the test item is applied to positive or negative pressure to determine leakages by monitoring the pressure curve. The pneumatic leak test is the most frequently used automated test method, as it is in practice sufficient for most applications using the test medium air which is unlimited. The leak test with air is suitable for leak testing with medium leak rates. The pneumatic test is the most common automated test method and is suitable for large leak and fine leak tests. The process offers low cost and an easy handling. Restrictions exist when testing very large volumes, damp or elastic components, applying very high pressures or inspecting workpieces that are subject to process-related temperature fluctuations. A leak test consists of the four steps of filling, calming, measuring and venting. In filling, test items are pressurized with the test medium and separated from the pressure source after reaching the test pressure or a defined time. The calming phase compensates for temperature differences and turbulence created in filling, as well as the time required to penetrate narrow transfer-sections and to affix gaskets. During the leak test with flow measurement, the test item is filled with air and the pressure in the test volume kept constant by means of inflowing air, so that the leaked air quantity can be determined by measuring the inflowing air volume. The measuring method used is either the ram pressure measurement or the mass flow measurement. Typical areas of application include the inspection of casting parts or components in machining production, as well as mounted pumps, valves, fittings, filters, containers, cylinder heads, crank, gearbox and clutch housings. Common fields of applications include the automotive and automotive supply industry, foundries, plastic part manufacturers, manufacturers of medical technology, gas technology, sanitary fittings, process-related pumps and valves and pneumatic manufacturers.