Precious Metal Karat Tester Model GK-2000  

Quickly, easily and accurately determine purity of precious metals and gold karat by two weighings ( By measuring the Specific Gravity) : one with the piece in a water tank, the other normally. An internal computer does all the calculations for you. Works only for solid metal pieces without set stones.
No acid, needles, or test stones needed
Leaves no scratches or stains on your gold after measurements
Wide karat range—from 9 to 24K
Tests other precious metals such as platinum and silver
Also functions as a normal gram scale
Advanced Model GK-2000 can measure up to 2,100g, which makes it possible to measure ingots and statues. Gold and Platinum measurement modes are available on GK-2000.