What role does the multimeter play in the range of use of the reference electrode
Use a DC voltmeter with appropriate input impedance, test leads, and a stable reference electrode such as a saturated copper/copper sulfate reference electrode (CSE), a silver/silver chloride electrode (Ag/AgCl), or a saturated potassium chloride electrode (KCl) calomel electrode, you can measure the potential of the pipeline to the electrolyte. CSE is generally used when the electrolyte is soil or fresh water, but it is not suitable for sea water. When using a CSE in a high chloride environment, the stability of the CSE must be checked before confirming the validity of the readings. Silver/silver chloride electrodes are usually used in seawater environments, and saturated potassium chloride calomel electrodes are more used in laboratories. However, multifaceted polymer colloid-saturated KCl calomel electrodes can also be used, but require a modest increase in the contact area to the environment.
How to use the reference electrode
1. Before use, unscrew the back cover first, add distilled water to make the reference electrode solution in a saturated state, and the solution is saturated if copper sulfate crystals precipitate, and then soak in clean water for about 20 minutes.
2. Put the reference electrode vertically into the soil near the object to be measured. If the soil is dry, add some water to ensure good contact between the reference electrode and the soil.
3. Connect the measurement wire of the reference electrode to the black terminal of the multimeter;
4. Connect the measured object (cathode wire) to the red terminal of the multimeter;
5. The multimeter is placed in the DC voltage position, and the range of the position is 2V.
6. The value displayed in this position is the potential to be measured.
7. When the surface of the electrode rod inside the reference electrode turns black, polish the electrode rod with fine emery cloth to the original color of copper.
8. In order to ensure that the contact area between the copper electrode and the copper sulfate solution is large enough, distilled water should be added when the solution is not enough; and after distilling water, there will be excess copper sulfate crystals in the solution.
9. When not in use for a long time, the bottom of the reference electrode should face up to avoid copper sulfate precipitation.
10. Do not use too much force during normal use, which may damage the reference electrode.
