(1) The electrode is small in size and easy to carry. The cavity is made of transparent plexiglass or ABS tube, which is convenient to observe the saturation of the copper sulfate solution inside.
(2) The electrode potential is stable, and the electrode is not easy to polarize.
(3) The electrode has a long service life, and the electrode cap is connected with the electrode cavity by a screw, which is convenient for filling the solution. One irrigation can be used for more than one year.
(4) The electrode structure is firm, the joint is corrosion-resistant, the leakage rate of the microporous membrane is suitable, and there is no visible liquid flow, which can be placed in a pocket.
A fully enclosed solid-state reference electrode based on a high molecular polymer, the liquid junction of which contains metal perchlorate, or metal sulfate, or metal fluoride, or silicate. The solvent part of the internal reference electrolyte consists of alcohols and water, or a polymer or copolymer of acrylamide and its derivatives and water. It can operate at temperatures up to 150 degree and pressures up to 100kg/cm.
A reference electrode is a reversible electrode system that has a stable and reproducible reversible electrode potential under specified conditions. Usually the main requirements for a reference electrode are:
(1) The reversibility of the electrode is relatively good, and it is not easy to polarize. This requires the reference electrode to be a reversible electrode with a high exchange current density (>10-5A/cm2). When the current flowing through the electrode is less than 10-7A/cm2, the electrode is not polarized. Even if a slightly larger current flows for a short time, the potential can quickly return to the original value after the power is turned off.
(2) The electrode potential is relatively stable and close to zero potential, so it is not easy to be polarized or passivated. After the reference electrode is made, its potential should be stable after standing for several days.
(3) The potential reproducibility is good. The potential of the same reference electrode made by different people or each time should be the same. The potential of each reference electrode produced each time should be the same after stabilization, and the difference should be less than 1 mV.
(4) The temperature coefficient is small, that is, the potential changes little with temperature. And when the temperature returns to the original temperature, the potential should quickly return to the original potential value.
(5) The preparation, actual use and maintenance are more convenient and durable. Reference electrodes that can meet the above requirements include hydrogen electrode, calomel electrode, mercurous sulfate electrode, mercuric oxide electrode, silver chloride electrode, etc. Most of these electrodes are type II electrodes.
