Say goodbye to guesswork and instability; this pH meter delivers accurate and consistent pH test results. With a resolution of up to 0.01 pH, it provides quick results and can test any liquid with a pH between 0 and 16. This digital pH meter is small and lightweight, about the size of a pen. Portable water pH meters are easy to carry, whether camping or swimming. Water is the source of life. This pH meter identifies high-quality water sources, providing you with healthy water. With this pH meter, say goodbye to acidic/alkaline water that is harmful to your skin and body. How to use the calibration solution: Rinse the pH meter electrode with pure water (2-3 times). 1. Immerse the pH electrode in a mixed phosphate standard buffer solution with a pH of 6.86 (25°C) and gently agitate. 2. Use a small screwdriver to adjust the calibration potentiometer until the displayed value matches the pH of the standard buffer solution at room temperature. 3. Rinse the electrode with pure water first, then calibrate it by inserting it into a dipotassium hydrogen phosphate standard buffer solution with a pH of 4.01. 4. After approximately two minutes, the displayed value should be within the error tolerance range compared to the pH value of the buffer solution. Two-point calibration refers to calibration using two different specifications of calibration solution; three-point calibration refers to calibration using three different specifications of calibration solution. Calibration typically begins at pH 6.86, followed by pH 4.01, 9, and 18 sequentially. After use, clean the electrode and turn off the power. Cover with the protective cover. Measurement range: 0.00-14.00 pH Accuracy error: 0.01 pH Resolution: 0.01 pH Operating temperature: 0-80℃ Calibration: 2-point and 3-point automatic calibration Electrode: Glass bulb Temperature compensation: ATC automatic temperature compensation Battery: 2 x 1.5V (LR44 button cell batteries) Color: Blue Material: Plastic Package contents: 1 x pH meter This package only includes the above contents and does not include other products. Note: Light reflection and different monitors may cause the color of the item in the picture to differ slightly from the actual item. The allowable measurement error is +/- 1-3cm.