In the third century BC, Archimedes found that the water level will rise to match the volume of object that plunge into the water. Only by method of object immersion in solution, we can be certain that there will be a uniform passivation of each and every part of the object surface.

This is extremely important because if one part of the object is not protected well, or if on one part of object passive layer is not restored in a satisfactory manner, this place is a potential risk for corrosion development. If corrosion is compared with the appearance of smoke (and where there's smoke there's fire), we can easily understand how important it is to prevent the possibility of the occurrence and spread of fire, respectively corrosion in our case.

In practice, often even worse situation occurs when corrosion starts to appear in hard to reach places (places that are only available by method of immersion), as in these cases, corrosion is only observed when it is already too late (when the fire has already spread up), and thus corrosion causes significant costs.