Abstract: The apparatus and method of the present invention facilitate surveys of buried structures, such as pipelines or the like, in particular by substantially automatically measuring and indicating distance information. Preferably that information is obtained by a transducer that produces serial data representing the length of wire bailed out from a portable reel and a cyclical counter responsive to such data for counting the serial data. A signalling device, such as a horn, strobe light, etc., is activated each time the counter completes a cycle as an indication that a predetermined distance has been covered since the last measurement was made and that the next potential measurement should be made. The number of pulses of such serial data counted in each cycle of the counter can be manually adjusted to obtain small or large distance intervals between test locations at which potential or other measurements are to be made to obtain a substantially continuous survey of the pipeline.

Abstract: An apparatus for making electrical surveys of structures contained in an electrolyte by measuring potential difference therebetween includes an electrode to contact the electrolyte proximate the structure, a wire electrically and mechanically connecting the apparatus with the structure, and an electronic system for automatically electrically sensing and storing the potential difference values taken at a plurality of locations along such structure. In the method for making structure-to-electrolyte potential difference surveys a supply of elongate electrical conductor is electrically and mechanically connected to the structure; the conductor is played out along the structure, and the electrolyte is contacted at plural test locations proximate the structure; and the potential difference at such test location is automatically sensed and stored.

Abstract: A cathodic protection system and method for steel reinforcement in concrete structures such as bridge decks, parking garage decks and highways utilizes platinized niobium or like metal wire anodes strategically positioned adjacent the concrete in a matrix of conductive carbonaceous material. The anode and matrix are preferably positioned in slots saw cut in the concrete surface avoiding the disposition of a conductive and wear resistant surface overlay which is not only expensive but which may exceed the design limitations of the structure. An impressed protective cathodic protection current is provided between the anodes and the steel of the structure. At places where the anode crosses in close proximity to reinforcing steel which may be exposed by the slot, or at places where cathodic protection current is not desired, a plastic sleeve may be placed over the anode.