Here is the link to the full article and video on Auto Motor und Sport.

Autozeitung publication from 2013

The Magneto Optical method largely replaces the Fry etching method and is based on a resonance process using magnetic energy and helps us to examine the embossed markings on a vehicle. Hidden numbers, double strokes, grinding marks and much more can be scrutinised, because the invisible is made visible. ...

There are essentially 3 measurement methods for non-destructive coating thickness measurements, for example of frame material or car body sheet metal or paint thickness measurements on car bodies: The magnetic-inductive measuring method for measurements on ferritic substrates such as sheet metal The eddy current method for measurements on non-ferrous substrates such as aluminium Ultrasound for substrate-independent measurements, or multi-layer measurements. The application of ...

Spectroscopy is used to determine the material composition, i.e. the percentage of elements that make up the material in question. The age of the material can then be determined to within a decade at best based on the alloy elements or the manufacturing process. Spectroscopy, as a forensic or scientific method of checking the authenticity of a vehicle, is used ...