EASY TO USERemove the protective cap and turn on the pH meter by pressing the "ON/OFF" key, immerse the electrode in the test solution to be tested, stir gently, and wait until the reading stabilizes. After finished, clean the electrode with distilled water, turn off the pH meter, and replace the protective cap HIGH PRECISION PH METER This pH meter provides fast and accurate reading of pH, you can get the digital reading after immersing the pH meter electrode in the solution, no need to work with colour charts or test strips, convenient and practical. Note: This product does not contain proofing materials EASY CALIBRATION pH meter is already calibrated by our professional staff and you can use it directly as soon as you receive it. Recalibration is required for long periods of inactivity and very frequent use. You can do recalibration easily with the help of the manual AUTOMATIC TEMPERATURE COMPENASTION The product provides full PH 0-14 measurements with temperature compensation which will make the result more accurate. The temperature of the testing liquid can vary from 0C - 60C (32F - 140F) WILDLY APPLICATIONThis digital pH meter is mini-size, weighing only 1.7 Oz, which allows you to take it in a pocket or bag. It is wildly used in testing pH for drinking water, swimming pools, aquariums, hydroponics, laboratory pH testing applications, and more