Copper-Copper Sulfate Reference Electrode (Cu/CuSo4)
Copper sulfate reference electrodes (CSE) are the most commonly used reference electrode for measuring potentials of underground structures and also for those exposed to fresh water.
CSE are not suitable for use off-shore environments or in a chloride electrolyte as the chloride ions migrate through
the porous plug and contaminate the CSE.
The portable type CSE are composed of a copper rod, saturated solution of copper sulfate and a non-conducting cylinder with a porous plug at the bottom as shown in above picture.
AFIC can supply a wide range of CSE those are intended to use in soil applications and are made for portable use or for permanent installations i.e., suitable to use along the pipeline route or under the above grade storage tanks etc.

Silver chloride electrode
Silver-silver chloride (Ag-AgCl) reference electrodes are most
commonly used for testing cathodic protection corrosion control
system in sea water environments.
The Ag-AgCl electrode is also used in concrete structures.
There are two types of Ag-AgCl reference electrodes; in one type
the silver electrode is exposed to seawater and in the other the electrode
is immersed in a potassium chloride (KCl) solution contained in a cylinder
with a porous plug.

 

Zinc Reference Electrode
Zinc is commonly used for onshore and offshore corrosion potential measurement. Zinc reference electrodes are not stable in
carbonates or at high temperatures. For underground use, the zinc electrode is packaged in a cotton bag containing the same
back fill as used around zinc anodes. In off-shore zinc electrodes used bare.