A method for monitoring the operating state of a set of circuit breakers includes the steps of arranging on the wall of each circuit breaker a synchronous triaxial digital magnetometer on a semiconductor chip, cyclically and synchronously reading temperatures measured by the magnetometers and from the temperatures measured by the magnetometers and a value of the ambient temperature, determining, for each circuit breaker, whether an internal heating temperature of the circuit breaker reaches a first temperature threshold which may be representative of an anomaly of the operating state of the circuit breaker.

A sensing system, and method of operating same, can act as a highly sensitive gradiometer. A first non-magnetic element, such as a sphere, is driven at a first resonance frequency along an axis. A magnet is attached to a second non-magnetic element, such as a plate, and driven at a second resonance frequency along the axis. The first non-magnetic element and the second non-magnetic element are coupled by a force along the axis, in resonance. The gradiometer is configured to determine a gradient magnetic field acting on one or more of the first non-magnetic element and magnet based on change in at least one resonance characteristic.

A magnetic field measuring device having a cantilevered, mechanically vibratable, rectangular substrate strip, at least one flat side of the substrate strip being coated with a magnetostrictive material system, further having drive means designed for the temporally periodic exertion of a force component directed perpendicular to the flat sides of the substrate strip on at least one part of a flat side of the substrate strip with a predetermined excitation frequency and having a detection device for detecting an electrical signal generated by the vibration of the substrate strip, wherein a. the substrate strip is formed from a material with a modulus of elasticity greater than 5 GPa and b. the excitation frequency is set up as a function of the dimensions of the substrate strip in such a way that the substrate strip oscillates in mechanical resonance and forms a U-mode, and c. the detection device has an induction coil which surrounds the substrate strip in a contactless manner and has a coil axis aligned along the substrate strip.

A device for sensing a magnetic field, comprising a closed superconducting loop configured to collect a magnetic field to be sensed, hereinafter external magnetic field, the closed superconducting loop having a path width (w.sub.p) and being provided with a constriction having a width (w.sub.c) narrower than the path width, the constriction generating a non-uniform magnetic field, hereinafter internal magnetic field, in response to the external magnetic field, a vibrating mechanical oscillator coupled to, or formed by the constriction and responsive to the internal magnetic field, and a detector configured to detect deflection or vibration of the mechanical oscillator and providing a signal indicative of the deflection or vibration.

A sensing system, and method of operating same, can act as a highly sensitive gradiometer. A first non-magnetic element, such as a sphere, is driven at a first resonance frequency along an axis. A magnet is attached to a second non-magnetic element, such as a plate, and driven at a second resonance frequency along the axis. The first non-magnetic element and the second non-magnetic element are coupled by a force along the axis, in resonance. The gradiometer is configured to determine a gradient magnetic field acting on one or more of the first non-magnetic element and magnet based on change in at least one resonance characteristic.

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 gradiometer includes a at least one magnet attached to a beam. The magnet moves in response to a magnetic force. A sensing element is configured to measure movement or deflection of the beam or magnet. The gradiometer is configured to determine a gradient of a magnetic field acting on the first magnet based on movement of the magnet. The gradiometer can further measure higher order gradients.

A micro-electro-mechanical system (MEMS) magnetometer is provided for measuring magnetic field components along three orthogonal axes. The MEMS magnetometer includes a top cap wafer, a bottom cap wafer and a MEMS wafer having opposed top and bottom sides bonded respectively to the top and bottom cap wafers. The MEMS wafer includes a frame structure and current-carrying first, second and third magnetic field transducers. The top cap, bottom cap and MEMS wafer are electrically conductive and stacked along the third axis. The top cap wafer, bottom cap wafer and frame structure together form one or more cavities enclosing the magnetic field transducers. The MEMS magnetometer further includes first, second and third electrode assemblies, the first and second electrode assemblies being formed in the top and/or bottom cap wafers. Each electrode assembly is configured to sense an output of a respective magnetic field transducer induced by a respective magnetic field component.

A device for sensing a magnetic field, comprising a closed superconducting loop configured to collect a magnetic field to be sensed, hereinafter external magnetic field, the closed superconducting loop having a path width (w.sub.p) and being provided with a constriction having a width (w.sub.c) narrower than the path width, the constriction generating a non-uniform magnetic field, hereinafter internal magnetic field, in response to the external magnetic field, a vibrating mechanical oscillator coupled to, or formed by the constriction and responsive to the internal magnetic field, and a detector configured to detect deflection or vibration of the mechanical oscillator and providing a signal indicative of the deflection or vibration.

A microwave resonator magnetic field measuring device (1) for measuring alternating magnetic fields, with a base plate (11) having at least one supporting/bearing/clamping point (111), at least one mechanical oscillator (12+13) formed as a microwave resonator in the form of a cantilever (13) having at least one magnetostrictive layer (12), the latter being connected and mounted at at least one point to the base plate (11) in the at least one supporting/bearing/clamping point (111), at least one input coupling means (161) for microwaves and at least one output coupling means (162) for microwaves, wherein the base plate (11) and the mechanical oscillator (12+13) formed as a microwave resonator are at least partly electrically conductive and electrically conductively connected to one another. Also, a magnetic field measuring method having a magnetic field measuring device according to the invention.