A probe for measuring a cathodic protection condition of a buried steel structure includes: a steel electrode; a reference electrode; and a coupon fabricated of a conductive material. The steel electrode, the reference electrode and the conductive coupon are positioned in an ionically conductive medium in proximity with each other and are isolated from direct electrical contact with each other.

A corrosion resistance tester for a coated metal material including a surface treatment film on a metal substrate includes: a container placed on the surface treatment film, and having a bottom surface in contact with the surface treatment film, the container including a plurality of water-containing electrolyte material holders that open through the bottom surface; the water-containing electrolyte material contained in each of the water-containing electrolyte material holders of the container, and being in contact with an associated one of a plurality of separate measurement target portions of the surface treatment film; a plurality of electrodes being each in contact with the water-containing electrolyte material contained in an associated one of the water-containing electrolyte material holders; an external circuit connecting the electrodes together; and a conduction means configured to conduct electricity to the metal substrate through the electrodes and the external circuit.

A surface corrosion monitoring system for a containment structure is disclosed. The surface corrosion monitoring system includes an electrode arrangement comprising an electrode electrically coupled with said structure, and a DC power supply arranged, in use, to deliver a predetermined voltage to the electrode which is sufficient to passivate and/or polarise or immunise an interior surface of said structure. The system also includes an electrode array comprising a plurality of spaced reference electrodes mounted on a framework, wherein each reference electrode is proximal to a localised interior surface of said structure and is arranged to measure a local potential indicative of current demand of the localised interior surface of the containment structure. A monitoring unit is also provided to monitor the local potentials measured by respective reference electrodes.

A sensor system is installed adjacent to the buried or submerged metallic pipelines using a plurality of sensors and transceivers. The sensor system monitors the pipeline for external corrosion control and recommends maintenance and repair at specific locations in the pipeline where external corrosion has occurred. The sensor system automatically receives periodic or continuous measurements through the plurality of sensors. The various sensors at various locations adjacent to the pipelines detect irregularities in the received sensor data at specific locations of the pipeline. The sensor data are stored in the system database and can analyzed to be used for monitoring and for transmitting repair alerts. The sensor system according to the present disclosure provides a reliable and an accurate assessment of the external corrosions of the pipelines. The sensor system further obviates the need of personnel walking along the pipelines to detect corrosion.

A sensor system is installed adjacent to the buried or submerged metallic pipelines using a plurality of sensors and transceivers. The sensor system monitors the pipeline for external corrosion control and recommends maintenance and repair at specific locations in the pipeline where external corrosion has occurred. The sensor system automatically receives periodic or continuous measurements through the plurality of sensors. The various sensors at various locations adjacent to the pipelines detect irregularities in the received sensor data at specific locations of the pipeline. The sensor data are stored in the system database and can analyzed to be used for monitoring and for transmitting repair alerts. The sensor system according to the present disclosure provides a reliable and an accurate assessment of the external corrosions of the pipelines. The sensor system further obviates the need of personnel walking along the pipelines to detect corrosion.

The metal tank portion of an electric water heater is protected against corrosion utilizing a corrosion protection system that detects a voltage potential between the sheath portion of a tank water-immersed electric heating element and the tank. In one embodiment of the corrosion protection system the sensed sheath/tank potential is utilized to enable a user of the water heater to accurately gauge the necessity of replacing a sacrificial anode extending into the tank. In another corrosion protection system, the sensed sheath/tank potential is utilized to provide impressed current cathodic protection of the tank and also to prevent dry firing of the electric water heater.

The metal tank portion of an electric water heater is protected against corrosion utilizing a corrosion protection system that detects a voltage potential between the sheath portion of a tank water-immersed electric heating element and the tank. In one embodiment of the corrosion protection system the sensed sheath/tank potential is utilized to enable a user of the water heater to accurately gauge the necessity of replacing a sacrificial anode extending into the tank. In another corrosion protection system, the sensed sheath/tank potential is utilized to provide impressed current cathodic protection of the tank and also to prevent dry firing of the electric water heater.

An electric field gradient sensor is presented, having a sensor body having an outer surface; and a plurality of electrodes distributed over the outer surface, each electrode having an electrode surface facing outward from the surface. The plurality of electrodes are arranged forming a plurality of electrode pairs, each electrode pair formed by a first electrode and a second electrode located on opposite sides of the sensor body. This sensor enables three-dimensional measurements of the electric field gradient along structures located in an electrically conductive medium, such as subsea structures, for example for monitoring the cathodic protection of such structure.

The invention relates to a propeller arrangement in a cathodic protection system for a marine vessel with a marine propulsion system, which cathodic protection system comprises a direct current power source with a positive terminal. The propulsion system comprises at least one driveline housing at least partially submerged in water; a torque transmitting drive shaft extending out of the driveline housing; and at least one propeller mounted on the drive shaft. According to the invention, the at least one propeller is electrically isolated from its drive shaft. Each electrically isolated propeller is electrically connected to a slip ring connector, which slip ring connector is in electrical connection with the positive terminal. The invention further relates to a vessel provided with such a propeller arrangement.

A system provides impressed current cathodic protection (ICCP) of a marine structure (50) and powers a load in a load arrangement (100) arranged on the marine structure (50) and in contact with the water (10). The power source provides a supply current to generate an electrical potential of the marine structure. The load arrangement (100) has an electrode arranged (130) to extend from the load arrangement into the water for transferring the supply current via the water. The load (20) is coupled between the electrode (130) and a power node (120). The power source is connected to the marine structure and to the power node. The load arrangement is arranged to use the supply current to provide power to the load. Thereto the supply voltage may have an AC component at a high frequency. The load may be an UV-C LED for emitting anti-fouling light.