Positioning measurement method for pH value
Two point positioning method (high-precision measurement method)
(1) Connect the electrode circuit, move the reference electrode and the PH electrode that has been activated for more than 24 hours into the standard buffer pH1 (e.g. pH1=4.00), and after the instrument response is stable, adjust the positioning knob until the instrument displays "0.00";
(2) Take the electrical level system out of the first standard solution, rinse it with deionized water, dry the surface of the electrical level with filter paper, and transfer it to the second standard solution (e.g. pH2=9.18). After the instrument response is stable, adjust the slope knob so that the instrument displays (△ pH=pH1-pH2=9.18-4.00=5.18), and then the slope knob cannot be moved again unless the electrode system is replaced;
(3) After the slope adjustment is completed, readjust the positioning knob so that the instrument displays the actual pH value of the second standard solution (9.18), and the 2-point positioning is completed;
(4) Remove the electrode from the second standard solution, rinse and dry it, then transfer it into the test solution. The value displayed by the instrument after the response is stable is the pH value of the test solution.
One point positioning method (rough measurement method)
(1) Adjust the temperature compensation knob to the solution temperature value;
(2) Rotate the slope compensation knob to the left to the head;
(3) Move the electrical level system into the standard solution (only one standard solution is used for one point method, such as pH=4.00), adjust the positioning knob to make the instrument display "4.00";
(4) After removing the water from the electric stage and rinsing it, transfer it to the solution to be tested. The value displayed by the instrument after the response is stable is the pH value of the solution to be tested.
