A system and method of effectively measuring a change in a gradient of a magnetic field. The systems include a first magnet and a second magnet mechanically coupled together and aligned along a polarization axis. The first magnet and the second magnet are positioned such that a pair of like magnetic poles of the first magnet and the second magnet face in opposite directions. Further, the first magnet and the second magnet are configured to move along the polarization axis in response to a magnetic field. A sensing system is configured to measure a change in a gradient of the magnetic field based on the movement of the first magnet and second magnet along the polarization axis in response to the magnetic field.

A magnetic sensor (1) includes: a nonmagnetic substrate (10); and a sensitive element (31) including a plurality of soft magnetic layers (105) (lower soft magnetic layer (105a) and upper soft magnetic layer (105b)) laminated on or above the substrate (10) and a conductor layer (106) laminated between the plurality of soft magnetic layers (105) and having higher conductivity than the plurality of soft magnetic layers (105). The sensitive element (31) has a longitudinal direction and a transverse direction and has uniaxial magnetic anisotropy in a direction intersecting the longitudinal direction. The sensitive element (31) is configured to sense a magnetic field by a magnetic impedance effect.

A magnetic sensor includes a sensor chip mounted on a substrate such that an element formation surface thereof is perpendicular to the substrate and a magnetism collecting member mounted on the substrate such that a surface thereof faces the substrate and a surface thereof faces the element formation surface. The arithmetic mean waviness Wa of the surface of the magnetism collecting member is 0.1 μm or less. When the arithmetic mean waviness Wa of the surface of the magnetism collecting member that faces the element formation surface is set to 0.1 μm or less, it is possible to significantly suppress a deterioration in detection sensitivity due to the presence of a gap between the element formation surface and the magnetism collecting member and to significantly reduce variations in detection sensitivity among products.

A wafer probe test system having a probe card with a probe head, a rotary magnet, a magnetic sensor positioned to sense the magnetic field of the rotary magnet and a controller coupled to the probe card, where the probe head has probe needles to engage features of test sites of a wafer in a wafer plane of orthogonal first and second directions, and the rotary magnet is rotatable around an axis of a third direction to provide a magnetic field to the wafer, in which the controller includes a model of magnetic flux density in the first, second and third directions at the respective test sites of the wafer as a function of a rotational angle of the rotary magnet, a probe needle height along the third direction and a measured magnetic flux density of the magnetic sensor.

A magnetic field detection device includes a magnetic field detection element, a modulator, and a demodulator. The magnetic field detection element has a sensitivity axis in a first direction. The modulator is configured to apply, to the magnetic field detection element, a stress oscillating at a first frequency and including a component in a second direction, the second direction being orthogonal to the first direction. The demodulator is configured to demodulate an output signal having the first frequency and outputted from the magnetic field detection element, and detect, on a basis of an amplitude of the output signal, an intensity of a measurement magnetic field to be received by the magnetic field detection element.

In the present disclosure, there is provided a permeability measurement jig including a first waveguide, wherein a signal line of the first waveguide comprises an excited magnetic part at one end side, and a magnetic field is generated at the excited magnetic part by an excitation signal, and a second waveguide, wherein a signal line of the second waveguide comprises a detection part at one end side, a detection signal is induced at the detection part due to an action of the magnetic field generated at the excited magnetic part to a measurement sample, and the detection part is placed on the excited magnetic part to face the excited magnetic part at a predetermined distance. A permeability measurement device having the permeability measurement jig and a permeability measurement method are disclosed.

A frac dart including a pressure housing, a mechanically actuated magnetic sensor including a first magnet outside of the pressure housing, a signal generator inside the pressure housing and in operable communication with the first magnet, and an electrical counter disposed in the frac dart responsive in increments to the signal generator.

The present disclosure relates to a magnetic-sensor device comprising a circuit board made of an electrically insulating material and having conductor tracks, and comprising a permanent magnet surface-mounted on the circuit board, and a magnetic-field sensor connected to the conductor tracks of the circuit board. An SMD component for populating a circuit board is also proposed, which SMD component comprises a permanent magnet and a magnetic-field sensor.

The present disclosure relates to a magnetic-sensor device comprising a circuit board made of an electrically insulating material and having conductor tracks, and comprising a permanent magnet surface-mounted on the circuit board, and a magnetic-field sensor connected to the conductor tracks of the circuit board. An SMD component for populating a circuit board is also proposed, which SMD component comprises a permanent magnet and a magnetic-field sensor.

A system for determining a stuck point of a pipe positioned within a wellbore includes a tubular housing and a sensor array positioned within the tubular housing. The system also includes ferromagnetic flux collectors and flux concentrators on either side of the sensor array. The flux collectors collect a magnetic flux that has been written to a portion of pipe. The flux concentrators intensify the flux to improve measurements of the flux that are acquired by the sensor array.