A cathodic protection unit (12) utilizes a signal generated by a conducting wire (14) inserted into a clamp body (16) after the clamp (16) is attached to a pipe (P). The wire (14) wraps a complete number of turns around the clamp structure. When the clamp is attached to the exterior of the pipe (P), the conducting wire (14) makes contact with the pipe (P) via a slight clamping pressure. Analyzing two signals generated by separate conducting wires (14) are used for cathodic protection.

A system comprises a cathodic protection system having an anode and configured to protect a protected structure from corrosion. The system comprises a monitoring circuit operatively coupled to the cathodic protection system. The monitoring circuit comprises an electrical-to-optical transducer. The electrical-to-optical transducer is configured to generate a light signal in response to electrical current flowing between the protected structure and the anode of the cathodic protection system, the protected structure and a reference electrode, or the reference electrode and the anode.

A monitored anode apparatus is provided. The apparatus includes a metal body having an exterior and a core, and a plurality of electrically conductive probes passing through the exterior and disposed at respective depths within the core. At least one of the plurality of conductive probes is disposed at a first depth, and at least one of the plurality of conductive probes is disposed at a second depth greater than the first depth. A bonding conductor is in electrical communication with the body and configured to create electrical continuity between the body and a protected structure. The metal body is configured as a galvanic anode, and at least one of the plurality of probes is configured to break electrical conductivity with the body upon galvanic consumption thereof.