PERMANENT REFERENCE ELETRODE FOR THE POTENTIAL MEASUREMENT OF BURIED METALLIC STRUCTURES

摘要

A permanent reference electrode (10, 10-1) for the potential measurement of buried metallic structures (ST) in order to verify their state of corrosion or cathodic protection including:- a zinc element or electrode (11) of elongated shape;- a special filling material (12) or backfill, based on gypsum, bentonite, cellulose fibre, sodium chloride and water, surrounding the zinc electrode (11);- a containment body (13) created around the backfill (12) and made of cementitious mortar (13') enriched with chloride ions; and- an external element or case (14), made of plastic material, that covers the cementitious containment body (13) and serve as the electrode case (10);where the cementitious mortar (13') of the containment body (13), in a respective area left uncovered by the outer casing (14), constitute the electrolyte contact with the ground (T) where the zinc reference electrode (10, 10-1) is buried, in a permanent way in proximity of the buried metallic structures (ST), of which the electrochemical potential is measured compared to the same reference electrode (10, 10-1).;In a further form of realization (10, 10-2) the zinc reference electrode does not include the cementitious containment body, but only the backfill (12) and a porous separator (19) adjacent to the last one, having a porosity likely to realize the electrolyte contact with the ground (T) where the reference electrode (10-2) is buried.;The zinc permanent reference electrode (10, 101-1; 10-2) of the invention is usefully likely to remain active for a long period of time in soil (T) where is buried and not to be subjected to the passivation phenomenon.