This is the preferred unit to test gold items that are less than 18 karats. In many cases it outperforms any other gold testing unit in the world. It reliably measures gold karattage to the nearest karat in the 6 to 18 karat range. For gold items above 18 karats unit reads 18 karats or more. Karat readings with corresponding European values appear directly on the LCD display. The unit also detects platinum and distinguishes between solid and gold plated items. Packaged in a Durable hard plastic case. Two years manufacturer's repair / replacement warranty. TB-289 Gel used with GXL-18 and GT-3000 Gold Testers (Yellow) Gel tubes have a shelf life of about one year when sealed. The Gel tubes are good for about: 340 tests. In hot climates with temperatures above 90 degrees Fahrenheit it is recommended to store the gel in the refrigerator but not freezer. 

The G-XL-18 Gold Tester detects 100% platinum and gold karatage in alloys commonly used in the jewelry industry. The base metals of the alloys are: Copper, Silver, Zinc, and Nickel. There are four types of gold (yellow, white, red (pink) and green) which consist of these metals in varying proportions. 

Owner's Manual

Manual (.pdf)

Manufacturer's Warranty

The manufacturer of the G-XL-18 Gold tester believes its instrument will provide fast and reliable method of determining the karat value of gold when used in accordance with the provided instructions. The manufacturer warrants that each instrument is free from defects in material and workmanship for a period of one (1) year from the date of purchase. This warranty applies to a G-XL-18 Gold tester that is not abused or improperly used and only if the device is used in accordance with the Owner's Manual. This warranty does not cover: any product where and attempt to disassemble the same is established; modification; alteration; unauthorized repair or service of the product or damages or defects resulting from accident or any events beyond the control of the manufacturer nor does this warranty cover batteries or accessories.