Standard Electronic Gem Tester (Presidium PGT II) Resolution_1g a watchmaker's eyeglass and a

a watchmaker's eyeglass and a good quality spring lug remover too - all in a fitted case

- as with all testers

the sensor must be kept dust-free

A friend sent me two Sovereigns and I could see

Standard Electronic Gem Tester (Presidium PGT II) Resolution_1g a watchmaker's eyeglass and aDETAILS Thermal meter, tests for 17 common groups of gemstones (about 40 varieties), enlarge the product picture to see the scale in detail. Works with any stone, loose or mounted in jewellery, even uncut stones. The only condition is that the stone (and tester) must be at room temperature. Instruction manual (pdf download) Video (youtube demonstration) Video (youtube calibration for serial numbers PTG111425 and after. Guide to buying electronic gem