How to use the calibration solution: Wash the pH meter electrode with pure water (2-3 times) 1. Immerse the pH electrode in the mixed phosphate standard buffer solution with a pH value of 6.86 (at 25°C), and shake it gently. 2. Use a small screwdriver to adjust the calibration potentiometer until the displayed value matches the pH value of the standard buffer solution at ambient temperature. Water is of life. PH meter for water, identify high-quality water sources, and bring you a . With a pH meter, bid farewell to acid/alkaline water that is harmful to the skin and body. Say goodbye to guesswork and instability, the pH meter for water bring you accurate and stable pH test results. With resolution of 0.01pH, pH tester could fast to get the testing result and can test the PH value for any 0-16PH liquid. Digital pH meter, small and light, just like a pen. Portable water pH meter could be carried with you, camping and swimming. 3. Clean the electrode with pure water first, and then insert the electrode into the pH4.01 potassium hydrogen phosphate standard buffer solution for calibration. 4. After about two minutes. The displayed value should be within the error tolerance range compared with the pH value of the buffer solution., Weight: 0.20723452628 Pounds, Manufacturer: Tuidzljd