Detecting forged gold bullion with eddy current NDT

摘要

With the global financial crisis, the price of gold has risen as investors escape risky equities and invest in less risky precious metals, and an endemic problem of gold bar/ingot forgery has arisen. Criminals are using the increase in the value of gold to their advantage by producing fake gold bars. The current method used by criminals is to plate tungsten with a thin layer of gold (about 0.1 mm). They do this because tungsten is a very similar density to gold but worth 1% of the value.