Invention, relates to the field of supersensitive biomagnetometry under presence of external electromagnetic interferences. In order to perform passive compensation of said interferences, design of device at the magnetometer input is proposed, comprising compensation elements and means for their moving including shifting, holding, and fixation units. In the basic embodiment, three short-closed wire contours are used which are orthogonally placed in space and independently moved up-down relative to the magnetometer or its input antenna. Contours are fixed in positions where minimum of external interference amplitude is achieved according to given field projection. Variants are proposed with cooling of meter and/or contours, location of contours inside the cryostat and their manufacturing from superconductors.

A sensor for sensing an external magnetic field along a sensing direction comprises a sensor bridge. The sensor bridge has a first sensor leg that includes a first magnetoresistive sense element and a second sensor leg that includes a second magnetoresistive sense element. The first and second sense elements have respective first and second pinned layers having the same reference magnetization. The first and second sense elements have respective first and second sense layers, each self-biased to have a first sense magnetization. A permanent magnet layer is proximate the second sense element. In the absence of an external magnetic field, the permanent magnet layer magnetically biases the first sense magnetization of the second sense layer produce a second sense magnetization of the second sense layer that differs from the first sense magnetization, and the first sense layer of the first sense element retains the first sense magnetization.

A sensor for sensing an external magnetic field along a sensing direction comprises a sensor bridge. The sensor bridge has a first sensor leg that includes a first magnetoresistive sense element and a second sensor leg that includes a second magnetoresistive sense element. The first and second sense elements have respective first and second pinned layers having the same reference magnetization. The first and second sense elements have respective first and second sense layers, each self-biased to have a first sense magnetization. A permanent magnet layer is proximate the second sense element. In the absence of an external magnetic field, the permanent magnet layer magnetically biases the first sense magnetization of the second sense layer produce a second sense magnetization of the second sense layer that differs from the first sense magnetization, and the first sense layer of the first sense element retains the first sense magnetization.

A current sensor includes a busbar carrying an electric current to be measured, a magnetic sensing element for detecting intensity of a magnetic field generated by the current flowing through the busbar, and a pair of shield plates that include magnetic materials and are arranged to sandwich the busbar in a thickness direction of the busbar. The shield plates include a conductive shield plate including a conductive magnetic material and a non-conductive shield plate including a non-conductive magnetic material. The conductive shield plate includes a slit penetrating therethrough. The magnetic sensing element is arranged at a position where the magnetic sensing element overlaps the slits in the thickness direction and does not overlap the conductive shield plate in the thickness direction.

A current sensor includes a busbar carrying an electric current to be measured, a magnetic sensing element for detecting intensity of a magnetic field generated by the current flowing through the busbar, and a pair of shield plates that include a magnetic material and are arranged to sandwich the busbar in a thickness direction of the busbar. The busbar includes a through-hole penetrating therethrough and current paths formed on both sides of the through-hole, the magnetic sensing element is arranged at a position overlapping the through-hole in the thickness direction of the busbar. The busbar is arranged in a space between the pair of shield plates such that the center in the thickness direction is located at a position offset from the center of the space in the thickness direction.

An automated circuit test system includes a magnetic sensor array configured to measure, at a plurality of locations, a magnetic field induced by a circuit under test. A circuit drive module can energize the circuit under test to induce the magnetic field. Optionally, the circuit drive module detects an electrical response from the circuit under test. Optionally, magnetic field data is combined with electrical response data prior to outputting the test result.

An automated circuit test system includes a magnetic sensor array configured to measure, at a plurality of locations, a magnetic field induced by a circuit under test. A circuit drive module can energize the circuit under test to induce the magnetic field. Optionally, the circuit drive module detects an electrical response from the circuit under test. Optionally, magnetic field data is combined with electrical response data prior to outputting the test result.

A magnetism detecting element detects a leakage magnetism from a scale, on which a magnetic signal with a constant period is recorded, and a relative position between the scale and the magnetism detecting element is detected. The magnetism detecting elements are arranged, along a detection direction of the magnetic signal relative to the scale, in a pattern with a pitch of 1/2n (n is a prime number of 3 or more) of a wavelength λ′ of a signal output by the element. Furthermore, as the pattern for cancelling m odd-order harmonics, the m-th power of 2 magnetism detecting elements are arranged within a range in which a pitch distance L of the magnetism detecting element farthest in the detection direction is expressed by L=(λ′/2)×(1/3+1/5+1/7+ . . . 1/(2m+1)).

A magnetic field recording system includes a headgear for a user; optically pumped magnetometers (OPMs) disposed in or on the headgear to detect magnetic fields and, in response to the detection, produce magnetic field data; at least one sensing modality including an optical sensing modality having at least one light source and at least one camera or light detector to receive light reflected or directed from the user and to produce an optical data stream; a tracking unit to receive the optical data stream and track a position or orientation of the headgear or user; a system controller to control operation of the OPMs and receive, from the tracking unit, the position or orientation of the headgear or user; and a processor to receive the optical data stream and the magnetic field data from the OPMs and analyze the magnetic field data using the optical data stream for validation.

In one example a magnetometer unit comprises logic, to receive first magnetic response data from a first magnetic sensor and second magnetic response data from a second magnetic sensor displaced from the first magnetic sensor, generate a composite response surface representation from the first magnetic response data and the second magnetic response data, and store the composite response surface representation in a non-transitory memory. Other examples may be described.