• Reference electrodes

The potential of underground pipelines and buried installations in soil or immersed in water is measured relative to reference electrodes (hallfcells). Reference electrodes are divided into three main categories depend on application such as: oil, gas and petrochemica and marine:

v Copper / Copper sulfate reference electrode (portable & permanent) for using in soils including Cl^-

v Zinc / Zinc sulfate reference electrode (portable & permanent) for using in soils including Cl^-

v Silver / Silver chloride reference electrode (portable & permanent) for using in marine environments

v Zinc Reference electrode for using in marine environment

The potential difference of different reference electrodes relation to hydrogen standard electrode at 25 ° C is as follows According to BS 7361:

• Ag/AgCl Reference electrode

BORNA Godaz silver / silver chloride reference electrode has been founded by a silver elctrode which its surface is coated with silver chloride by thermal or electrolytic processes. The most important feature of this electrode is high degree of stability. This electrode is directly used in seawater or brackish river waters. Also, this electrode is used In other applications, such as steel in concrete structures.
these electrodes are placed in a container for mechanical protection due to application of them in seawater environment. Therfore, the holes are created on these compartments in order to establish of contact with the electrolyte. These electrodes should be immersed in seawater for several hours before usage. Also, end of electrode cable are insulated to prevent short circuits. It should be noted that These electrodes must be kept in a potassium chloride saturated solution when they are not used.