Calibrate pH meter with buffer solution
Adjust the pH meter with a buffer solution until the indicator correctly reads the pH value of the solution. You can calibrate it according to the following method.
(1) Prepare two 200mL clean beakers for cleaning the sensor with distilled water, pH 4 and pH 7 buffer solutions, and a thermometer for measuring the temperature of the buffer solution.
(2) Pour 50-100mL of buffer solutions with pH 4 and pH 7 into beakers, respectively.
(3) Remove the sensor from the bracket. If the sensor is installed in an immersion bracket, remove the sensor bracket and protective component together from the immersion bracket.
(4) Clean the sensor electrode, wipe off water droplets with degreasing cotton, and immerse the electrode in a buffer solution with pH=7.
(5) The pH value of the buffer solution varies with temperature. Measure the temperature of the pH=7 buffer solution and compare the measured values.
(6) Rotate the STD (calibration function key) clockwise or counterclockwise until the pH transmitter displays the same value as measured in step (5).
(7) Completely wash off the pH 7 solution from the electrode and immerse the electrode in a pH 4 buffer solution.
(8) Measure the temperature of a pH 4 solution and compare the measured values.
(9) Adjust SLOPE (electrode response slope) until the pH transmitter displays the same value as measured in step (5).
(10) Repeat steps (4) to (6) until the pH transmitter displays the correct value. If the accurate pH value is read, the calibration of the buffer solution is completed.
