Review on 💎 Lotustech Diamond Tester: Highly Accurate Diamond Tester Pen for Novices and Experts - Black, Battery Included by Jennifer Roberts

You need to wait for it to warm up and then calibrate the diamond tester based on room temperature and diamond size. There is a table for this on the back of the device. In most cases, at least for me, the diamond being tested is over 0.5 carat and between 50 and 85 degrees Fahrenheit, so you should move the calibration wheel until 2 lights are on and then test. with the device. There is a review where a person says the tester is rubbish because it works with a crystal but if you read the product description a real crystal tests for an 8 but a real diamond for a 9, that's why. It's also probably miscalibrated. Depending on what you're testing, you'll get some false positives. I tested it at diamond level when I touched the doorknob with it once. This is because the tester is testing thermal conductivity. I don't know how it works 100%, but I understand that the tester heats the surface it is testing and at the same time measures the temperature, and the ratio between the heat generated and the heat measured at the surface of the gem affects the result. Readings, so I can understand that with a crystal the size of a baseball, for example, readings can be a little inaccurate. At the same time, they were very accurate when testing real stones. We've tested it on every clean "gem" in the house, including plastic rhinestones. Only diamond and moissanite are rated 9 or higher.