The use and maintenance of the electrodes of the Ph meter
1. When the composite electrode is not in use, it can be fully soaked in 3M potassium chloride solution. Do not soak with washing liquid or other water-absorbing agents.
2. Before use, check the bulb at the front end of the glass electrode. Under normal circumstances, the electrode should be transparent without cracks; the bulb should be filled with solution without air bubbles.
3. When measuring a solution with a high concentration, shorten the measurement time as much as possible, and wash it carefully after use to prevent the measured liquid from adhering to the electrode and polluting the electrode.
4. After cleaning the electrodes, do not wipe the glass membrane with filter paper, but dry it with filter paper to avoid damage to the glass membrane, prevent cross-contamination, and affect measurement accuracy.
5. During the measurement, pay attention to the silver-silver chloride internal reference electrode of the electrode should be immersed in the chloride buffer solution in the bulb to avoid the digital jumping phenomenon in the display part of the electric meter. When using, pay attention to gently shake the electrode a few times.
6. The electrode cannot be used in strong acid, strong alkali or other corrosive solutions.
7. It is strictly forbidden to use in dehydrating medium such as absolute ethanol, potassium dichromate, etc.
First, the preparation and storage of PH standard buffer solution
1. The pH standard substance should be stored in a dry place. For example, the mixed phosphate pH standard substance will deliquesce when the air humidity is high. Once deliquescence occurs, the pH standard substance 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.
⒊The prepared pH standard solution should be diluted with a smaller beaker to reduce the pH standard solution sticking to the beaker wall. In addition to emptying the plastic bags or other containers that store pH standard substances, they should also be rinsed with distilled water several times, and then poured into the prepared pH standard solution to ensure that the prepared pH standard solution is accurate.
4. The prepared standard buffer solution can generally be stored for 2-3 months. If turbidity, mold or precipitation are found, it cannot be used any longer.
5. Alkaline standard solution should be sealed and stored in polyethylene bottles. Prevent carbon dioxide from forming carbonic acid after entering the standard solution and lower its pH value.
