Abstract: A method for assessing a structure arranged in an electrolyte may include connecting an electric source between the structure and an earth, and imposing, on the structure, a primary current with at least three frequencies including a first frequency of a duration and an amplitude, a second frequency of a duration and an amplitude, and a third frequency of a duration and an amplitude, a series of currents with the first and second frequency being separated by a time gap. Fields of electric fields may be measured with an instrument having first, second, and third sensors and a positioning system. Each sensor May be configured to measure a field of an electromagnetic field along the structure for each of the frequencies. A primary field resulting from an electric current within the structure based on the measured field may be computed.

Abstract: A method for assessing a structure arranged in an electrolyte includes connecting an electric source between the structure and a low resistive connection to the electrolyte via an earth, providing a direct and/or alternating current via the source, measuring a direct and an alternating voltage between a first and second electrode, the electrodes being in contact with the electrolyte at a measurement location and being arranged at a distance to each other. The first and second electrodes are connected to a voltage measurement device. A direct potential and an alternating potential is determined between the structure and the electrolyte at the measurement location, which may include measuring the DC potential and the AC potential between the structure and at least one additional electrode in contact with the electrolyte. A property of the structure may be assessed based on the measured DC and AC voltages, and the DC and AC potentials.

Abstract: A method for assessing a structure arranged in an electrolyte includes connecting an electric source between the structure and a low resistive connection to the electrolyte via an earth, providing a direct and/or alternating current via the source, measuring a direct and an alternating voltage between a first and second electrode, the electrodes being in contact with the electrolyte at a measurement location and being arranged at a distance to each other. The first and second electrodes are connected to a voltage measurement device. A direct potential and an alternating potential is determined between the structure and the electrolyte at the measurement location, which may include measuring the DC potential and the AC potential between the structure and at least one additional electrode in contact with the electrolyte. A property of the structure may be assessed based on the measured DC and AC voltages, and the DC and AC potentials.

Abstract: A method for assessing a structure arranged in an electrolyte may include connecting an electric source between the structure and an earth, and imposing, on the structure, a primary current with at least three frequencies including a first frequency of a duration and an amplitude, a second frequency of a duration and an amplitude, and a third frequency of a duration and an amplitude, a series of currents with the first and second frequency being separated by a time gap. Fields of electric fields may be measured with an instrument having first, second, and third sensors and a positioning system. Each sensor May be configured to measure a field of an electromagnetic field along the structure for each of the frequencies. A primary field resulting from an electric current within the structure based on the measured field may be computed.