A magnetic flux measurement apparatus and method for nondestructive thickness imaging of metallic objects. The apparatus can primarily be used for thickness imaging of concentric metallic pipes, such as inner tubing and outer casing pipes in downhole applications. The magnetic flux measurement apparatus includes a transducer that includes a magnetic field source, magnetic flux sensor rings and a magnetic flux guide lens both positioned in alignment with a lateral axis of the magnetic field source. The magnetic flux guide lens is made of ferromagnetic material with high magnetic permeability that can direct flux lines into a predetermined sensor area for higher sensitivity and signal to noise ratio.

An exemplary inventive optimization model delineates a three-dimensional geometric environment for situation therein of electromagnetic sources and an electromagnetic sensor array used for measuring electric and magnetic fields emanating from the electromagnetic sources. Based on measurements and computations relating to electrical, magnetic, and structural physical properties, the geometric environment is stratified into air, sea, and seafloor regions as well as into electromagnetically distinct zones. The design of the electromagnetic sensor array is optimized through an iterative process involving successive determinations as to how well the electric and magnetic fields emanating from the electromagnetic sources may be calculated based on measurements taken in the geometric environment by the electromagnetic sensor array. Every instance of the electromagnetic sensor array in the iterative process is uniquely located and/or uniquely configured vis-à-vis every other instance. Design optimization can be performed with respect to various frequencies or frequency ranges.

Various embodiments of the teachings herein include an apparatus for measuring a magnetic field of a conductor of an electric current. The apparatus may include three magnetic field sensors arranged on a circumference of a non-circular ellipse. The three magnetic field sensors are arranged equidistantly along the circumference of the ellipse. The magnetic field is measured without using a flux concentrator.

A magnetometer system for medical use comprises one or more induction coils for detecting a time varying magnetic field. Each coil has a maximum outer diameter of 10 cm or less, and a configuration such that the ratio of the coil's length to its outer diameter is 0.9 or more, and the ratio of the coil's inner diameter to its outer diameter is 0.6 or more. Each induction coil comprises a magnetic core. The magnetometer system further comprises a detection circuit coupled to each coil and configured to convert a current or voltage generated in the coil by a time varying magnetic field to an output signal for use to analyse the time varying magnetic field.

A magnetic sensor includes a base material, a plurality of magnets provided at predetermined spacing on the base material, and a plurality of magnetic detection parts respectively provided close to the plurality of magnets. Each of the plurality of magnetic detection parts outputs a signal in accordance with change in the magnetic field accompanying deformation of the base material.

A magnetic sensor array device is comprised of an array of magnetic sensors arranged on a common semiconductor substrate to measure the multi-axis magnetic field of an arbitrary sized region at high speed with high spatial resolution and high magnetic resolution. This invention further improves a multi-axis magnetic sensor array device fabricated on a common semiconductor substrate with additional optimizations to provide for variable spatial resolution, variable magnetic resolution, and a novel secret key derivation.

A semiconductor device includes a vertical Hall element provided in a first region of a semiconductor substrate, and having the first to the third electrodes arranged side by side in order along a first straight line; a circuit provided in a second region of the semiconductor substrate different from the first region, and having a heat source; and a second straight line intersecting orthogonally a current path for a Hall element drive current which flows between the first electrode and the third electrode. The second line passes a center of the vertical Hall element, and a center point of a region which reaches the highest temperature in the circuit during an operation of the vertical Hall element lies on the second straight line.

A method of determining an orientation α,β of a magnet which is pivotable about a reference position having a predefined position relative to a semiconductor substrate, comprising: a) determining at least two of the following magnetic field gradients: i) a first magnetic field gradient dBx/dx; ii) a second magnetic field gradient dBy/dy; iii) a third magnetic field gradient dBz/dx; iv) a fourth magnetic field gradient dBz/dy; b) determining a first angle α based on at least one of the magnetic field gradients; c) determining a second angle β based on at least one of the magnetic field gradients. A sensor device is configured for performing this method. A sensor system includes such sensor device and a magnet, optionally connected to a joystick.

A method of magnetic sensing uses at least two magnetic sensing elements including a first and a second magnetic sensor element. The method includes: a) measuring in a first configuration a combination of the first and second signal obtained from both sensors; b) measuring in a second configuration an individual signal obtained from the first sensor only; c) testing a consistency of the combined signal and the individual signal, or testing a consistency of signals derived therefrom, in order to detect an error. A sensor device is configured for performing this method. A sensor system includes the sensor device and optionally a second processor connected thereto.

A magnetic field detection device of an embodiment of the disclosure includes: a first magnetic field detection element having a first resistance value increasing upon application of a first magnetic field in a first direction and decreasing upon application of a second magnetic field in a second direction; and a second magnetic field detection element having a second resistance value decreasing upon application of the first magnetic field and increasing upon application of the second magnetic field. The first and second magnetic field detection elements each include first and second magneto-resistive effect films coupled in series. The first magneto-resistive effect film has a first major-axis direction inclined at a first inclination angle relative to the first direction. The second magneto-resistive effect film has a second major-axis direction inclined at a second inclination angle relative to the first direction. The magnetic field detection device satisfies conditional expressions (1) and (2).