1. When the composite electrode is not used, it can be fully immersed in 3M potassium chloride solution. Never use washing liquid or other absorbent reagents to soak and wash.

13. When measuring a solution with a large concentration, shorten the measuring time as far as possible, and carefully clean it after use to prevent the measured solution from adhering to the electrode and polluting the electrode.

4. After cleaning the electrode, don't wipe the glass film with filter paper, but use filter paper to absorb it, so as to avoid damaging the glass film, preventing cross-contamination and affecting the measurement accuracy.

5. Pay attention to the fact that the silver-silver chloride internal reference electrode of the electrode should be immersed in the chloride buffer solution in the bulb to avoid digital jumping in the display part of the ammeter. When using, pay attention to gently swing the electrode a few times.

1. The pH reference material should be stored in a dry place. For example, the mixed phosphate pH reference material will deliquesce when the air humidity is high. Once deliquescence occurs, the pH reference material cannot be used.

2. Secondary distilled water or deionized water should be used to prepare pH standard solution. If it is used for 0.1 grade pH meter measurement, ordinary distilled water can be used.

3. The pH standard solution should be diluted with a smaller beaker to reduce the pH standard solution on the beaker wall. Plastic bags or other containers for storing pH standard materials should be cleaned, and distilled water should be used for washing for many times, and then poured into the prepared pH standard solution to ensure the accuracy of the prepared pH standard solution.

4. The prepared standard buffer solution can generally be stored for 2-3 months. If it is found to be turbid, moldy or precipitated, it cannot be used any more.

5. Alkaline standard solution should be sealed in polyethylene bottles. Prevent carbon dioxide from forming carbonic acid after entering the standard solution and reduce its pH value.