Diaphragm metering pump pH meter correction method: 1 instrument in continuous use, once a day to be calibrated. 2. Remove the Q9 short-circuit plug at the measurement electrode socket; insert the composite electrode at the measurement electrode socket; if no compound electrode, insert the electrode converter plug at the measurement electrode socket; insert the glass electrode plug at the converter socket The reference electrode is connected to the reference electrode interface. 3. After the power is turned on, press the "pH / mV" button, the instrument into the pH measurement state, preheated 30min. 4. Press "Temperature" button to show the solution humidity value (the temperature indicator light is on), then press "Confirm" key, the instrument returns to the pH measurement status after confirming the solution temperature. 5. Insert the electrode washed with purified water into standard buffer solution with pH = 6.86 (25 ℃). Press "Positioning" key after the reading is stable (the pH indicator blinks slowly to indicate the calibration of the instrument) The reading is the pH value of the solution at that time; then press the "Enter" key, the instrument enters the measurement state and the pH indicator stops flashing. 6. Insert the electrode washed with purified water into a standard buffer solution at pH = 4.01 (25 ° C) (or pH = 9.18 (25 ° C)). Press the Slope key until the reading has stabilized (the pH indicator flashes , Indicating that the instrument calibration in the slope state) so that the reading of the solution temperature at the current pH, and then press the "confirm" key, the instrument enters the pH measurement state, the pH indicator stops blinking, the calibration is complete. 7. Repeat 5 ~ 6 until no more adjustment Positioning or slope adjustment knob instrument display value and the standard buffer solution pH value ≤ ± 0.02 so far.