All About Leaks

Evaporation (outgassing) is the release of adsorbed molecules at room temperature and pressure, while desorption (degassing) is the forced evaporation of molecules by either applying greater heat or decreasing the ambient pressure. 

Diffusion is the movement of atoms or molecules through solids, liquids, or gases. The rate of transport is always governed both by concentration variations in the material and by the size ratio of the diffusing material and the material it s passing through. Once the material has diffused to the surface, it can be desorbed into the system. 

Permeation (and absorption) are both conditions that only apply when the penetrating molecule is much smaller than the molecules of the wall material. A molecule of any size can be involved in adsorption. 

Internal External leakage leakage (virtual (real 

Permeation is a three part process. The material is first absorbed into the material it is about to pass through. Then, the contaminant diffuses through the material. Finally, the contaminant desorbs into the system. 

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