1 Scope
This document specifies the method for non-destructive thickness measurement via the magnetic type of electrodeposited nickel coatings, also called “e-nickel”, on magnetic or non-magnetic substrates.
It is possible that the method is not applicable to autocatalytic (electroless) nickel coatings, since these coatings are often non-magnetic due to their chemical composition.
For the purposes of this document, two types of substrates are distinguished:
nickel coatings on magnetic substrates (type A coatings);
nickel coatings on non-magnetic substrates (type B coatings).
Not all instruments are applicable to both types of coating.
The effective measuring ranges of instruments using the principle of magnetic attraction are up to 50 µm for type A coatings and up to 25 µm for type B coatings.
For instruments using the principle of reluctance, the effective ranges are much greater, up to 1 mm or even more. This method is applicable to both types of coatings.