How to use precision acidity meter (PH meter)
Preparation before pH meter measurement
1) Install the composite electrode on the electrode rod, and insert the electrode plug into the measuring electrode socket at the rear of the instrument.
2) Connect the temperature sensor to the sensor socket (if manual setting is performed, there is no need to connect the sensor).
3) Clean the electrode with distilled water.
Determination of electrode potential (mV) value
Place the electrode in the solution to be measured, press the "mV" key, and the "mV" indicator light will light up. Stir the solution to make it uniform. After the reading is stable, the displayed value is the "mV" value of the electrode potential of the solution, and the ± polarity is automatically displayed.
pH calibration
Because the zero-potential conversion coefficient of each electrode is different from the theoretical value, and each of them is different. Therefore, to measure pH value, the electrode must be pH calibrated.
1) Temperature setting. Press the "Temperature Setting" key to put the temperature indicator light at the temperature setting position. At this time, the first digit on the display screen flashes. Use the "→" key to move the setting digit. At the same time, press the "↑" key to make the temperature display value the desired value. Measure the temperature value of the standard solution at this time, and then press the "Confirm" button to confirm.
2) After the electrode is washed with distilled water, blot it dry with filter paper, then put the electrode into the first standard solution, press the "pH/pH calibration" button to put the instrument in the pH measurement state, and then press "pH" after the reading is stable. /pH Calibration" key to put the instrument in the pH calibration state, and press the "→" or "↑" keys to make the displayed value the pH value of the standard solution at the current temperature. Press the "Confirm" button again to confirm.
3) After washing the electrode with distilled water, blot it dry with filter paper. Put the electrode into the second standard solution (select a standard solution with a similar pH value based on whether the pH value sample solution to be measured is acidic or alkaline, and its pH value does not differ from the first standard solution by more than 3 pH units), press " "pH/pH Calibration" key puts the instrument in the pH measurement state. After the reading is stable, press the "pH/pH Calibration" key to put the instrument in the pH calibration state. Press the "→" and "↑" keys to make the displayed value the current temperature. Set the pH value of the standard solution and press the "Confirm" key to confirm.
4) The instrument calibration is completed.
4. Determination of pH value
1) After cleaning the electrode with distilled water, wash it with the test solution more than twice, and place the electrode in the test solution.
2) Set the temperature according to the temperature setting method in pH calibration so that the temperature value is the temperature of the sample being measured at this time.
3) Press the "pH/pH Calibration" button to make the "pH" measurement indicator light on, and stir the solution with a glass rod to make it uniform. After the reading is stable, the displayed value is the pH value of the sample being measured.
