Two-point calibration method to calibrate the pH meter (acidity meter)
1, preparation work
Prepare three beakers each containing 250ml of pure water (to ensure calibration accuracy), and pour pH7 mixed phosphate reagent into the first cup, and pour pH4 potassium hydrogen phthalate reagent into the first cup ( Or pH9 sodium tetraborate reagent depends on the user's monitoring needs, generally use pH4 reagent.), and fully stir with a stirring bar to make it completely dissolved. The third cup of pure water is used for electrode cleaning.
2, Calibration steps
pH7 point calibration: put the electrode into the pH7 mixed phosphate solution, and wait for the pH meter to display a stable value. Press and hold the CAL/ENT key for three seconds, and the display (4) will display 'Calibrating, please wait', and at the same time display The display (5) starts flashing. After 14 seconds, the display (5) stops flashing and displays '6.86'. At the same time, the display (4) displays 'pH7-calibration complete'. At this time, the pH7 calibration is completed. The electrodes were taken out and placed in a beaker filled with pure water for cleaning.
PH4 point or PH9 point correction:
Put the cleaned electrode into the pH4 potassium hydrogen phthalate solution (or pH9 sodium tetraborate solution, depending on the user's choice) and wait for the pH meter to display a stable value. Press and hold the CAL/ENT key for three seconds, the display ( 4) Display 'Calibrating, please wait', and the display screen (5) starts flashing. After 14 seconds, the display screen (5) stops flashing and displays '4.01', and the display screen (4) displays ' Calibration completed', the normal display will resume after three seconds (if the user chooses pH9 sodium tetraborate, the display (5) will display '9.18'). After the calibration is completed, connect the pt100 temperature electrode to the PT100 terminal on the rear board, and the temperature will be automatically compensated. If the display screen (4) displays 'Sensor Aging' when the user calibrates, it means that the electrode has aged.
