Evaluation of the fineness of precious alloys by means of non destructive analysis

摘要

Several different methods can be used to define the fineness of a precious alloy: from the merely comparative touchstone method to the extreme precision of ICP-M5. However; the majority of tests, and in particular those guaranteeing the level of precision requested by law, are destructive. According to new market requirements, demanding a fineness test for every single piece, it is clear that a destructive method is no longer applicable. Aim of this work is to review the underlying physics of the X-Ray Fluorescence (XRF) test method applied on silver alloys and define the correlation between sample characteristics (shape, roughness, dimension, composition) and analysis output.