A New Permanent Reference Electrode for Field Use with Cathodic Protection in Protection of Underground Pipelines and Storage Tanks

Abstract The Cu/CuSO4 electrode (CSE) is typically used as a reference electrode (RE) for monitoring the corrosion protection of pipelines and storage tanks. It requires periodic internal electrolyte replacement due to seasonal wet/dry cycles of soils. It also experiences problems including: (1) agglomeration of CuSO4 crystals at the electrode tip resulting in loss of electrochemical connection between the cell and soil and (2) leaking of the CuSO4 electrolyte into the surrounding soils. The leaking electrolyte may result in deposition of Cu on the steel surface which accelerates corrosion of the structure. To overcome those problems, a new RE is developed that is designed to (1) recover from dryout quickly when the soil rewets, (2) avoid salt agglomeration and (3) prevent accelerated corrosion of the monitored structure as a result of RE electrolyte leakage. In this paper, attempts toward this goal and experimental results are reported and discussed. This work proved the concept that metal/metal oxide rod as electrode and a hygroscopic salt as electrolyte salt would be viable for developing field REs.