For assayers and refiners of precious metals, material analysis instruments must fulfill exacting requirements. Just determining the precise gold content is not enough: It is important to ascertain the complete composition of the alloy, including elements like platinum or silver. In addition to reliably generating comprehensive, accurate, and reproducible results, the ideal analysis procedure should also be fast, easy to use, and – of course! – non-destructive.
Fire assaying (cupellation) is the traditional method for determining gold content, whether for gold bars, coins or valuable jewellery. However, serious handling issues outweigh this method’s good precision, as it is time consuming, requires the use of acids and, worst of all, damages the item in the process.
Fortunately, the well-established X-ray fluorescence method (XRF) provides an excellent alternative for analysing the content of precious metals – without damaging the object. Fischer's XRF instrument, the GOLDSCOPE SD® 550, is designed especially to determine precious metal content. Providing precision rates of 0.3‰ or better, the the GOLDSCOPE SD® 550 can help assayers and refiners significantly reduce the number of cupellation tests required, saving them valuable time and resources
The the GOLDSCOPE SD® 550 both determines the material content and assesses coatings all in one analysis cycle, with extra-ordinary repeatability: Table 1 shows the results from ten measurements of a 14-carat gold object coated with 400 nm of rhodium, taken specifically to verify the instrument’s repeatability precision.