Presidium Gem Tester II (PGT II): Home Improvement. Buy Presidium Gem Tester II (PGT II): Diamond Testers - ✓ FREE DELIVERY possible on eligible purchases. Includes: GemTester II, Probe Pen, AC Adapter, User Handbook, Warranty Registration Card, Case 。 Built-in Calibration (CAL) and Glass Test Discs 。 Probe Pen with a Retractable Thermoelectric Tip isthe industry's thinnest at 0.6mm for testing diamonds as small as 0.02 ct 。 Enclosed AC Adapter or you may use 2 AA Batteries for on the go 。 The Gem Tester II (PGT II) developed to distinguish between diamonds and its other simulants using the principles of thermal conductivity. The Probe Pen consists of two linked thermometers. One heated electronically while the other is cooled by the gemstone being tested. The difference in temperature creates an electrical output which is displayed on the Analog Dial on the front of the Gem Tester II. The Analog Dial shows a color stone estimator display to assist you to distinguish between popular colored gemstones. Note that this thermal tester is not able to differentiate between natural Diamonds and Moissanites. Your tester has been calibrated during the manufacturing process. Before testing, please clean and dry the gemstone to be tested. Test gemstones at room temperature (6-0 degrees fahrenheit). 。 。 。