PRESIDIUM® Gem Indicator (PGI) is the industry's only multi-gemstone tester which utilizes the properties of electro-thermal conductivity conductivity and Presidium's signature, retractable probe tips, which maintain consistent pressure against the gemstone during testing, to accurately verify the authenticity of 31 different types of gemstones. The PGI is a handheld version of the revolutionary Presidium Gem Tester/Colored Stone Estimator. Color input function for enhanced accuracy ◆ Metal-contact audio alert ◆ Three hours continuous use ◆ Results in under six seconds ◆ No waiting time between tests ◆ Easy-to-read display with LED indicator ◆ Low-battery indicator ◆ AC and battery power ◆ One-year manufacturer's warranty The Presidium Gem Indicator probe consists of two linked thermometers; one which is heated electronically, while the other is cooled by the gemstone being tested. The difference in temperature creates an electrical output, which is then amplified and displayed on the crisp backlit LED display. The PGI is powered by a 120 - 230 V adapter (sold separately) or three (3) AAA batteries (sold separately)..
