GMW GMW14711 PDF

If light metals (such as aluminum, magnesium) come into contact with precious metals or solid bodies conducting electrons (e.g. graphite), this may lead, in the presence of electrolytes, to the preferential corrosion of the light metals.

To avoid this contact corrosion, elastomers, plastics and adhesives shall have a sufficiently high insulation resistance. The same applies if such materials are in contact with painted light metal surfaces as the insulating paint layer may not offer sufficient protection against contact corrosion, because of faults or damages in the part.

The insulation resistance depends both on the specific volume resistance and on the specific surface resistance of the test piece.

The determination of the specific volume resistance is performed to check the uniformity of the insulating material. The specific volume resistance is considerably affected by temperature and moisture.

Note: Nothing in the standard supersedes applicable laws and regulations unless specific exemption has been obtained.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.