Abstract: A system for monitoring and alternatively adjusting the electrical energy input and output of remotely located corrosion protection rectifiers on a section of a longer pipeline includes three elements. The first element is a monitoring unit which monitors electrical input, output voltage, output amperage and level of applied cathodic protection of the electrical energy provided to the pipeline by a rectifier. This data on electrical energy is then transmitted to the second element, a low-level communication satellite. The low-level communication satellite then retransmits the data to the third element, a management data center. The information received at the management data center may be monitored, recorded or transformed into adjustment signals which are then retransmitted via the low-level communication satellite back to the rectifier on the pipeline.

Abstract: An apparatus for measuring cathodic protection voltage levels on a concealed conductive structure, includes a probe having a standard half cell reference electrode, a working electrode and an auxiliary electrode mounted in a fixed spacial relationship to each other, wherein the reference electrode, working electrode and auxiliary electrode are each in contact with an electrolytic solution. A voltage measuring device is provided for receiving a voltage from said reference electrode. The voltage measuring device provides an indication of the voltage difference between the reference electrode and a common reference point. A switch is included for connecting and disconnecting the working electrode with the common reference point. A voltage detecting circuit detects voltage between the concealed conductive structure, which is subject to a cathodic protection voltage, and the common reference point.

Abstract: When explosive fuels such as hydrocarbons are pumped into or out of a barge or tanker, a metallic conduit having an insulated flange therein is typically connected to the barge. The method of this invention involves connecting the barge to the earth through a barge-grounding cable, connecting the metallic conduit to the earth through a conduit-grounding cable, whereby a grounding test circuit is established with a current source connected between the earth and the grounding cables. A flange resistor is connected across the insulated flane to form a flange circuit. The currents flowing through the grounding cables are being continuously monitored in the grounding circuit to determine the presence of a broken connection or of an ineffective electric contact. A continuity test is also continuously being made of the flange insulation in the flange.

Abstract: The sensor system senses a drop in the flow of impressed cathodic protection current to a minimum threshold level. A potential difference is developed which is a sample of the cathodic protection current. A comparator receives the sample potential difference and normally produces an output control signal which drops to substantially zero when the cathodic protection current drops to a predetermined threshold level. A relay responsive to the control signal then switches a signaling device to its signaling condition. A standby battery is also coupled to the signaling device through the relay. In the event of any failure in the sensor system or in the primary source of power energizing the sensor system, the standby battery becomes connected to the signaling device to cause it to change to its signaling condition.