QUICK TEST - Just turn on the coffee tester, drip a few drops of coffee into the metal sample channel, press the READ button and wait 5 seconds to get the result. There are no complicated command keys and the operation is very simple LARGE BACKLIT COLOR DISPLAY - The unit with a large backlit display allows you to easily see the readings clearly in low light conditions. All results are displayed instantly and intuitively, allowing you to quickly understand the test results MULTI-PURPOSE TESTER - A tester for coffee lovers to understand the coffee extraction rate, allowing you to quickly know how to adjust brewing for reference. Additionally, coffee distributors and coffee chains can use the device for business evaluation TEMPERATURE COMPENSATION FUNCTION - The refractive index is affected by temperature, so we set up the automatic temperature compensation (ATC) function, which can provide accurate readings at various temperatures to ensure accuracy and consistency ENERGY SAVING - When you complete the test but forget to turn off the power, the device will automatically shut down within 60 seconds if no operation is performed. Therefore, this feature will save energy