A transducer includes a planar coil coupled to a magnetic flux guide. The magnetic flux guide includes an array of nanowires. The transducer could include a plurality of magnetic flux guides and a plurality of planar coils stacked together. The flux guides and planar coils could alternative in the stacked configuration.

Closed loop current transducer includes a fluxgate sensing unit, a compensation coil wound around the fluxgate sensing unit, and a transducer housing mounted around the compensation coil, the fluxgate sensing unit comprising a fluxgate housing, a ring-shaped fluxgate magnetic field detector mounted in the fluxgate housing, and a magnetic shield mounted in the fluxgate housing, the magnetic shield surrounding the fluxgate magnetic field detector. The fluxgate housing includes first and second central parts, each central part comprising a radially inner side wall, a radially outer side wall and a base wall joining the inner side wall to the outer side wall, a sensor housing portion being formed on one side of the base wall and receiving the fluxgate magnetic field detector therein.

Closed loop current transducer includes a fluxgate sensing unit, a compensation coil wound around the fluxgate sensing unit, and a transducer housing mounted around the compensation coil, the fluxgate sensing unit comprising a fluxgate housing, a ring-shaped fluxgate magnetic field detector mounted in the fluxgate housing, and a magnetic shield mounted in the fluxgate housing, the magnetic shield surrounding the fluxgate magnetic field detector. The fluxgate housing includes first and second central parts, each central part comprising a radially inner side wall, a radially outer side wall and a base wall joining the inner side wall to the outer side wall, a sensor housing portion being formed on one side of the base wall and receiving the fluxgate magnetic field detector therein.

An apparatus for measuring an electric current through a bus bar comprises a compensation coil and a magnetic field sensor. The bus bar has a through-hole dividing the electric current flowing through the bus bar into at least two partial currents flowing around the through-hole. The compensation coil is disposed in the through-hole and generates a compensation field. The compensation field compensates a plurality of magnetic fields generated by the partial currents and/or an external magnetic field such that a magnetic flux density of a resulting magnetic field at a predetermined position of the through-hole does not exceed a predetermined threshold. The magnetic field sensor is disposed in the through-hole and detects the magnetic flux density of the resulting magnetic field at the predetermined position. The magnetic field sensor emits an output signal corresponding to the detected magnetic field.

An apparatus for measuring an electric current through a bus bar comprises a compensation coil and a magnetic field sensor. The bus bar has a through-hole dividing the electric current flowing through the bus bar into at least two partial currents flowing around the through-hole. The compensation coil is disposed in the through-hole and generates a compensation field. The compensation field compensates a plurality of magnetic fields generated by the partial currents and/or an external magnetic field such that a magnetic flux density of a resulting magnetic field at a predetermined position of the through-hole does not exceed a predetermined threshold. The magnetic field sensor is disposed in the through-hole and detects the magnetic flux density of the resulting magnetic field at the predetermined position. The magnetic field sensor emits an output signal corresponding to the detected magnetic field.

A handheld pipeline inspection tool for inspecting a section of pipe. The tool includes two wings mounted to opposing sides of a central body using hinges. Each wing includes an excitation coil and is rotatable about the hinges so that the wings may be positioned around pipes of different sizes. Each excitation coil is energized by alternating current (AC) produced by an AC generator within the body. The energized excitation coils generate magnetic fields that interact with the section of pipe. An array of magnetometers within the body detects variations in the magnetic field due to the presence of defects within the adjacent section of pipe. In this fashion, the handheld pipeline inspection tool facilitates the inspection of pipelines in unusual configurations and hard to access conditions.

According to one embodiment, a magnetic sensor includes a first element, a first wire, and a first magnetic part. The first element includes a first magnetic layer, a first counter magnetic layer, and a first nonmagnetic layer provided between the first magnetic layer and the first counter magnetic layer. A direction from the first counter magnetic layer toward the first magnetic layer is along a first direction. The first wire extends in a second direction crossing the first direction. The first magnetic part includes a first region and a first counter region. At least a portion of the first wire is between the first region and the first counter region in the first direction.

According to one embodiment, a magnetic sensor includes a first element, a first wire, and a first magnetic part. The first element includes a first magnetic layer, a first counter magnetic layer, and a first nonmagnetic layer provided between the first magnetic layer and the first counter magnetic layer. A direction from the first counter magnetic layer toward the first magnetic layer is along a first direction. The first wire extends in a second direction crossing the first direction. The first magnetic part includes a first region and a first counter region. At least a portion of the first wire is between the first region and the first counter region in the first direction.

A magnetic detection apparatus includes a core to which magnetism to be detected is applied, an exciter configured to excite the core with an excitation signal, a detector configured to detect induced voltage according to a time change of magnetic flux generated by the core, a wave detector configured to detect a wave from a signal corresponding to the induced voltage by using a detection signal corresponding to the excitation signal and to generate a signal according to the magnetism to be detected, and a signal converter configured to generate and output to the exciter an excitation signal that has a spread spectrum of a signal having an excitation frequency and to generate and output to the wave detector a detection signal that has a spread spectrum of a signal having a detection frequency of twice the excitation frequency.

A magnetic detection apparatus includes a core to which magnetism to be detected is applied, an exciter configured to excite the core with an excitation signal, a detector configured to detect induced voltage according to a time change of magnetic flux generated by the core, a wave detector configured to detect a wave from a signal corresponding to the induced voltage by using a detection signal corresponding to the excitation signal and to generate a signal according to the magnetism to be detected, and a signal converter configured to generate and output to the exciter an excitation signal that has a spread spectrum of a signal having an excitation frequency and to generate and output to the wave detector a detection signal that has a spread spectrum of a signal having a detection frequency of twice the excitation frequency.