Product Description How to use The first step: Remove the protective sleeve, first clean the electrode of the PH meter with distilled water, and use filter paper to drain the water attached to and around the electrode. The second step: Tap "ON/OFF to turn on the power, insert the instrument into the solution under test, submerge the electrode under test in the solution, gently shake the instrument to drive away the bubbles, and read the displayed number after the value is stable. After use, press ON/OFF" to turn off the POWER, wash the electrode with water, and put on a protective sleeve. Calibration method 1.Pour the 6.86, 4.01, 9.18 standard buffer solution and distilled water into different clean cups. 2.In order to calibrate accurately, each buffer solution is divided into two cups, one cup is filled with water to rinse the electrode, and the other solution is used for calibration. 3.Tap the "switch button to turn on the power. 4.Put the electrode in a PH6.86 standard solution and shake gently until the value is stable. 5.Press the "CAL" button for about 5 seconds to let go, and the instrument enters the automatic correction state until the displayed value is consistent with the pH value of the standard buffer solution at this temperature, that is, the PH6.86 point correction is completed. 6.Clean the electrode, dry it, put the electrode in a PH4.01 standard buffer solution, and shake gently until the value is stable. 7. The measurement methods of PH4.01 and PH9.18 are the same as the measurement of PH6.86 standard buffer solvent. Warm reminder 1.The button does not operate for 5 minutes, and the meter automatically shuts down to extend the battery life. 2.The height of the pen end immersed in the solution should be less than 4CM, so as not to affect the accurate reading. Specifications : Measuring Range: 0.00-14.00 Accuracy: 0.01 Error:0.05PH Operating Temperature: 0~50C Probe Type: Glass bulb electrode Package Included: 1 x PH Meter 3 x correction powder 1 x manual Note: 1. Due to the different monitor and lighting effect, the actual color of the item may be slightly different from the color shown on the pictures. 2. Please allow 1-3cm error due to manual measurement. (1 inch = 2.54 cm) Thanks for your support :)