To answer the question, how good or bad is the protection against corrosion with drying cabinets compared with nitrogen cabinets, the following facts have to be considered:
The drying cabinet removes the H2O molecule from the internal atmosphere by drying the air, but doesn’t change the O2 concentration from the 21% amount of fair. Different from the N2-cabinet, which exchanges the complete internal atmosphere and removes all oxygen, regardless how it is binded. Considering the interaction between oxigen and metal, semi-conductors- and other surfaces, O2 is the supplier of oxygen for the corrosion. This molecule can only react with the metalic surface by means of an electrolyte. The electrolyte exists in the form of a very thin invisible layer of water on the surface of the metal, which will be formed wenn the humidity level is higher than 10% rH.
To reach an effective protection against corrosion, a nitrogen cabinet is in comparison with a drying cabinet just as effective. Both remove again and again a component of the corrosion reaction and stop it. As the drying cabinet eliminates the moisture much quicker, the corrosion will stop as soon as the storage takes place. Wenn a door is opened the moisture level can’t rise enough to build a layer of water.
A nitrogen cabinet needs a high volume of N2, until it has eliminated the amount of oxygen of the internal atmophere. During this time the corrosion will continu with decreasing velocity.
The all ready absorbed moisture in the stored components can’t be removed by nitrogen, in opposite to the drying cabinet, which not only protects the stored materials but also dries them.
The very low energy consumption of drying cabinet offers low energy costs and therefore it is in the long run much more efficient and inexpensive than the nitrogen cabinet
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