Detection of leaks is done by implementing a leak testing. It is also used to ascertain the penetration rate of different types of liquid or gas from the inner area of a compact component or assembly to the outside or from outside to the inside. This has effect on the permeation extension or the difference in the pressure level of the two regions. It has become essential to use the term “leak” for mentioning an actual passage or disruption through which a fluid flows or goes . “Leakage is the amount of fluid passed through the leak. “Leak rate” is calculated by measuring the amount of fluid flow per unit of time, under a defined set of conditions. It is properly expressed in units of mss/ per standard unit of time. The rate of flow of atmospheric air is defined as “Standard Leak”. Conditions under which it is determined are inlet pressure is 0.1 Mpa ±5%; temperature is 298K±5, dew point is less than -298K and outlet pressure is less than 1 Kpa.
Reference of the term “minimum detectable leak” is to the tight passage or tiny hole which can be identified. Considering this, “Minimum detectable leak rate” implies the smallest traceable rate of fluid. The minimal amount of leakage required for a testing instrument to generate signal can be efficiently determined. This tiniest detectable signal is basically utilized to denote the sensitivity of the instrument in tracing leakage. Not depending on the conditions of tests, but the sensitivity of the instrument under a test is to a greater extent depends on the set conditions of fluid, temperature, pressure and fluid.