Pawn broking, bank, jewelry shop, precious-metals recovery, jewelry factory, Gemstone Testing Center,precious metals researching.etc. In accordance with archimedes principle water buoyancy method, GB/T1423 of precious metals testing standard,and so on. Combine archimedes principle with micro electronic technique;adopt sensor imported from Germany,the purity can be calculated through measuring density of precious metals.features of no damage on sample;simple operation,fast and accurate. K value of gold,PT value of platinum,density value,purity percentage can be measured.