Be sure to know before using the pH meter

It must be known with any pH meter that the pH meter must be calibrated with a pH standard solution before measuring the pH of the sample.

For samples with a measurement accuracy below 0.1 pH, a one-point calibration method can be used to adjust the pH meter. A pH 6.86 or pH 7.00 standard buffer is generally used. Some acidometers have an accuracy of only 0.2 or 0.1 pH, and only one "positioning" adjustment knob is provided on the pH meter.

The procedure for operating a one-point calibration is as follows:

(1) First measure the standard buffer temperature, look up the table to determine the value of the pHs, and adjust the temperature compensation knob to this temperature.

(2) Rinse the electrode with pure water and spin dry.

(3) After immersing the electrode in the buffer solution, shake it and place it still. After the reading is stable, adjust the positioning knob to make the instrument display the pH value of the standard solution.

(4) Take out the electrode and dry it.

(5) Measure the sample temperature and adjust the pH meter temperature compensation knob to this temperature value.

(6) Immerse the electrode in the sample solution, shake it and place it still. Display a stable reading.