Copper/ copper sulphate reference electrodes are produced in two portable and permanent. Portable type with probe is suitable for many applications, while permanent type is used on the tank bottoms, next to pipelines and in some cases as an important part of smart transformer rectifiers, etc.
The silver/ silver chloride reference electrodes consist of a silver electrode whose surface is coated with silver chloride by thermal or electrolytic methods. These electrodes show a high degree of stability. The silver/ silver chloride reference electrode is used directly in seawater or saline river water. In other applications such as steel in concrete, is used silver/ silver chloride/ potassium chloride reference electrode.
The use of a metal reference electrode to measure potential difference in direct contact with the electrolyte around the structure may not make sense, but the reference zinc electrode in seawater is suitable for many applications. Successful samples have also been observed in the use of this electrode in the tanks bottom with the backfill, although many designs today use copper/ copper sulphate reference electrodes. Zinc reference electrode is cheaper than silver/ silver chloride reference electrode and is used instead unless a high degree of stability is required. In addition, the mechanical stability of this type of electrode is much higher than other reference electrodes which have different and fragile components.
