Cathodic protection system and electrode holder

Claim 1

A REFERENCE ELECTRODE ASSEMBLY FOR USE WITH A CATHODE PROTECTION SYSTEM FOR A METAL STRUCTURE WHEREIN THE METAL STRUCTURE IS EXPOSED TO AN ELECTROYLTE AND FORMS THE CATHODE OF THE SYSTEM, SAID ASSEMBLY COMPRISING AN ELECTRODE ELEMENT FORMED OF ELECTROCHEMICALLY STABLE MATERIAL, AN INERT, DIELECTRIC CHEMICALLY RESISTANT HOLDER FOR THE ELECTRODE ELEMENT, AND MEANS FOR ATTACHING THE HOLDER TO THE METAL STRUCTURE, SAID HOLDER COMPRISING A RELATIVELY FLAT, DISK-LIKE STRUCTURE HAVING A STREAMLINED EXTERIOR SURFACE AND INTERIOR WALLS FORMING A CAVITY IN THE INTERIOR THEREOF FOR RECEIVING THE ELECTRODE ELEMENT, A POROUS, DIELECTRC, CHEMICALLY INERT MATTING ENCASING THE ELECTRODE ELEMENT WITHIN THE CAVITY OF THE HOLDER AND SPACING THE ELECTRODE ELEMENT FROM ALL OF THE SAID INTERIOR WALLS FORMING SUCH CAVITY SAID HOLDER BEING FORMED WITH FLUID PASSAGES THEREIN LEADING TO AND FROM THE CAVITY FOR FLOW OF THE ELECTROLYTE TO THE ELECTRODE ELEMENT SAID ELECTRODE ELEMENT, SAID MATTING, SAID INTERIOR WALLS BOUNDING THE CAVITY AND THE FLUID PASSAGES LEADING TO AND FROM THE CAVITY BEING SO CONSTRUCTED AND ARRANGED AS TO CAUSE THE ELECTRODE ELEMENT TO BE SURROUNDED ON ALL SURFACES THEREOF BY A RELATIVELY STAGNANT BATH OF ELECTROLYTE, AND SAID ELECTRODE ELEMENT HAVING AN ELECTRICAL CONDUCTOR CONNECTED THERETO AND LEADING THEREFROM TO THE EXTERIOR OF THE HOLDER FOR CONNECTION TO AN ELECTRICAL CIRCUIT.