One point calibration procedure for the pH meter

Any kind of pH meter must be calibrated after the pH standard solution can measure the pH value of the sample. For the measurement accuracy of the sample below 0.lpH, the instrument can be adjusted by a little extreme standard method, generally choose pH6.86 or pH7. 00 standard buffer. Some instruments have an accuracy of only 0.2pH or 0.lpH, so the instrument only has a "positioning" adjustment knob. Here's a step-by-step guide to the calibration of the pH meter.

1. Measure the standard buffer temperature, check the table to determine the pHs at this temperature, and adjust the temperature compensation knob to this temperature.

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

3. After the electrode is immersed 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.