Reference Electrode for Permanent Installation in Soil
To ensure that satisfactory levels of Cathodic Protection (CP) are being achieved on buried structures and above ground storage tank bottoms, reference electrodes are permanently installed to measure steel potentials. They can also be used as a sensing electrode to control the DC output power supply to the CP systems.
The WE200 permanent reference electrodes have been specifically designed for direct burial in moist soil and can be installed along pipeline routes at key monitoring points e.g. test stations, drain points, cased crossings, isolation joints, HVAC parallelisms etc. and are also suitable for installation below tank bottoms to measure CP potential levels.
The WE200 reference electrode consists of a highly stable silver/silver chloride element enclosed in an acetal housing and surrounded by a solid electrolyte (with 0.5M chloride ion concentration), an enlarged micro porous ceramic plug allows contact with the electrolyte and ionic conduction. These electrodes can be directly installed into moist soil but in dry soils the electrode impedance can be very high in relation to the impedance of the measuring circuit. Thus, it would be essential that the reference electrode is bagged in a conductive backfill i.e. bentonite, gypsum and sodium sulphate and the measuring circuit has a high impedance, preferably 30MegOhm or greater.
Typical applications: underground pipelines, underground in-plant pipework, underground tanks, mounded tanks, above ground storage tank bottoms.
Reference Electrode for Portable Installation in Soil
The WE200-P reference electrode consists of a highly stable silver/silver chloride element enclosed in an acetal housing with a removable ceramic cone and protective end cap. Removing the ceramic cone allows an internal liquid electrolyte with 0.5M chloride ion concentration to be added and periodically refreshed around the Ag/AgCl element and the enlarged micro porous ceramic cone is then replaced to seal the unit. The ceramic cone allows an intimate interface with the electrolyte and ionic conduction. These electrodes are portable and are fitted with a 4mm socket into which the test lead from the meter can be connected via a 4mm banana plug.