How to use PHS-3C PH meter:
It consists of a main unit and a composite electrode. There are four knobs on the main unit, they are: selection, temperature, slope and positioning knobs. Install the instrument and electrodes, turn on the power switch at the rear of the instrument, and preheat for half an hour. Before measuring, first calibrate the pH meter, we use the two-point positioning calibration method, the specific steps are as follows:
Adjust the selector knob to PH gear;
Use a thermometer to measure the temperature of the solution to be tested and read, for example, 25ºC. Adjust the temperature knob to the measured value of 25ºC.
Adjust the slope knob to the maximum value.
Open the electrode sleeve, wash the electrode head with distilled water, carefully dry the electrode head with absorbent paper, put the composite electrode into the standard buffer solution mixed with phosphate, make the solution submerge the glass ball of the electrode head, and shake gently , and after the reading is stable, adjust the knob to make the displayed value be 6.86 when the standard pH value of the solution is 25ºC.
Take out the electrode, wash it, blot dry, put it in the standard buffer solution of potassium hydrogen phthalate, shake well, and after the reading is stable, adjust the slope knob so that the displayed value is 4.00 when the standard pH value of the solution is 25ºC.
Take out the electrode, wash it, blot it dry, put it in the standard buffer solution mixed with phosphate again, shake it well, and after the reading is stable, adjust the positioning knob, so that the displayed value is the standard pH value of 6.86 at 25ºC.
Take out the electrode, wash it, blot dry, put it in the buffer solution of potassium hydrogen phthalate, shake well, and after the reading is stable, then adjust the slope knob so that the displayed value is the standard pH value of 4.00 at 25ºC.
Take out the electrode, wash and blot dry. Repeat the calibration until the measured values of the two standard solutions are basically consistent with the standard pH value.
After the calibration process is over, enter the measurement state. Put the composite electrode into the beaker containing the solution to be tested, shake it gently, and record the reading after the reading is stable.
