Abstract: A system for measuring a variation in a distance of an axis of rotation of an object relative to a point in a plane perpendicular to this axis comprises at least two sensors for measuring a value representing an angular position of said object about said axis, at least a first of said sensors, whose position is fixed relative to said point, comprising a magnetometer suitable for measuring the magnetic field generated by said object whose magnetization varies around its circumference; and means for determining said variation of distance on the basis of a variation in an angular deviation between said sensors relative to the axis, from one revolution of said object to the next.

Abstract: A graphite-based sensor includes an undoped graphite structure that adsorbs foreign atoms and molecules. A magnetization detection device includes a substrate on which the graphite structure is adhered, a current source by which a current is applied to the substrate and the graphite structure, and a voltage measuring device coupled to the substrate. When the graphite structure adsorbs the gas molecules, the graphite structure exhibits a ferromagnetic-type behavior, and a corresponding voltage generated in the magnetic detection device changes.

Abstract: A resolver includes: a resolver rotor attached to a rotational shaft; an annular resolver stator that is provided on a radially outer side of the resolver rotor and that has a plurality of teeth each opposed, across a clearance, to an outer peripheral face of the resolver rotor and circumferentially arranged at given intervals; and a case member having a cylindrical fit portion to which an outer peripheral face of the resolver stator is fitted. At least three protrusions, each protruding radially outward, are formed at given circumferential intervals on the outer peripheral face of the resolver stator, so that the outer peripheral face of the resolver stator is press-fitted to an inner peripheral face of the fit portion at positions at which the protrusions are formed.

Abstract: A sensor device for height measurement, air spring comprising a sensor device for height measuring and a corresponding method allowing determining the height also under rough conditions like noisy, dusty or vibrating environments.

Abstract: A polarization microscope optically detects the effect of the magnetic field from a sub-optical resolution magnetic structure on a magneto-optical transducer. The magneto-optical transducer includes a magnetic layer with a magnetization that is changed by the magnetic field produced by the magnetic structure. The saturation field of the magnetic layer is sufficiently lower than the magnetic field produced by the magnetic structure that the area of magnetization change in the magnetic layer is optically resolvable by the polarization microscope. A probe may be used to provide a current to the sample to produce the magnetic field. By analyzing the optically detected magnetization, one or more characteristics of the sample may be determined. A magnetic recording storage layer may be deposited over the magnetic layer, where a magnetic field produced by the sample is written to the magnetic recording storage layer to effect the magnetization of the magnetic layer.

Abstract: A steering tool is movable by a drill string to form an underground bore along an intended path. A sensing arrangement of the steering tool detects its pitch and yaw orientations at a series of spaced apart positions along the bore, each position is characterized by a measured extension of the drill string. The steering tool further includes a receiver. At least one marker is positioned proximate to the intended path, for transmitting a rotating dipole field to expose a portion of the intended path to the field for reception by the receiver. The detected pitch orientation, the detected yaw orientation and the measured extension of the drill string are used in conjunction with magnetic information from the receiver to locate the steering tool. The steering tool may automatically use the magnetic information when it is available. A customized overall position determination accuracy can be provided along the intended path.

Abstract: A magnetoresistive angular sensor and sensing method, in which an external magnetic field generator is used to provide a first mode in which a dc external magnetic field is provided in a predetermined direction and which dominates over the magnetic field generated by the input device being sensed. In a second mode, the external magnetic field is smaller. The angular sensor arrangement outputs from the two modes are combined, and this enables the input device angular orientation to be determined with offset voltage compensation.

Abstract: An apparatus and a method provide an output signal indicative of a speed of rotation and a direction of rotation of a ferromagnetic object capable of rotating. A variety of signal formats of the output signal are described.

Abstract: Systems and/or methods are provided for a dual-channel inductive proximity sensor. The sensor can include a sensing element which includes a core having a first cavity and a second cavity, a first coil accommodated within the first cavity of the core, and a second coil housed within the second cavity of the core. Each coil can be independently driven by oscillators to generate respective magnetic fields. The magnetic fields can be monitored to determine whether detection of a target object occurs.

Abstract: Embodiments related to the generation of magnetic bias fields for a magneto sensor are described and depicted.

Abstract: A magnetic field sensor device 1 includes a sensor section 100 that includes a magneto-impedance device 110 having a magnetic amorphous structure, and rod-shaped core sections 130 and 131 that guide a magnetic field to the magnetic amorphous structure in a longitudinal direction with respect to the magnetic amorphous structure. The core sections 130 and 131 may be provided on either side of the magnetic amorphous structure in the longitudinal direction. The core sections 130 and 131 may be disposed so that the longitudinal direction of the magnetic amorphous structure coincides with the longitudinal direction of the core sections 130 and 131. The magnetic field sensor device 1 may include environmental magnetic field cancellation means 140 and 141 that generate a correction magnetic field that cancels the environmental magnetic field input to the magnetic amorphous structure.

Abstract: A method of monitoring an extent of a hydrocarbon reservoir (2) below the earth's surface (4), includes the steps of applying a current between a bottom current electrode (6) and a top current electrode (8) that is part of a plurality of electrodes that are spaced apart from one another along a part of the earth's surface located above and optionally over the hydrocarbon reservoir. The bottom current electrode is positioned below the hydrocarbon reservoir. The method includes the step of measuring an electrical potential, which is caused by the current, by means of a measurement electrode (10A) that is also part of the plurality of electrodes. The method includes the step of inferring from the measured electrical potential the extent of the hydrocarbon reservoir, in a direction that is oriented substantially parallel with the earth's surface.

Abstract: The present invention relates to a measuring device (10) of the electric properties of solid or liquid geological samples, such as, for example, rocks, preferably from oil or gas reservoirs, and saturation fluids of the same, comprising a hollow body (11, 12) consisting of a first upper half-shell (11) and a second lower half-shell (12), the upper and lower half-shells (11, 12) coaxially sliding one inside the other, inside the body (11, 12) there being a housing seat (23) for a substantially cylindrical sample, two pairs of electrodes (13, 14) being envisaged facing the housing seat (23) for the injection of current into a sample and for the measurement of the voltage at the ends of the sample, characterized in that the pairs of electrodes (13, 14) are pairs of coplanar electrodes, each situated at one end of the housing seat (23).

Abstract: A bearing residual life prediction method, a bearing residual life diagnostic apparatus and a bearing diagnostic system can be provided. The bearing diagnostic system 20 includes: an eddy current tester 11 that measures the impedance X of a certain portion of a bearing 24 before and after the use of the bearing; a bearing information transmitter 30 that transmits bearing information s1 containing the impedance X; and a bearing information receiver 31 that receives the information; a diagnostic section 12 that obtains the residual life information s2 of the bearing 24 based on the received impedance X; and a life information transmitter 36 that transmits the residual life information s2; and a life information receiver 40 that receives the information. Hence, the bearing used by the user can be inspected nondestructively, and the residual life of the bearing can be predicted.

Abstract: A magnetic inspection station for tubular members and methods for operating the same have a longitudinal flaw detection assembly adapted to pass a circumferential magnetic field through a tubular member and a transverse flaw detection assembly adapted to pass a longitudinal magnetic field through the tubular member. The magnetic fields cause congregation of a ferromagnetic particles sprayed on the tubular member in a magnetic particle inspection fluid. The congregation of ferromagnetic particles indicates a flaw in the tubular member. The magnetic inspection station includes a clamping apparatus positioned closely adjacent to the magnetic inspection station and adapted to support the tubular member within the magnetic inspection station and exert a compensating force on the tubular member to resist the magnetic forces generated by the longitudinal flaw detection assembly and the transverse flaw detection assembly.

Abstract: The invention provides a method for detecting and imaging magnetic metalloproteins. A substrate is provided. A plurality of magnetic metalloproteins are formed on the substrate. The magnetic metalloproteins are detected and imaged by magnetic force microscopy (MFM) to obtain topographic images, phase images and MFM images of the magnetic metalloproteins.

Abstract: A method and apparatus of constructing a signal for a controlled source electromagnetic survey is described. In one embodiment, a method is described that includes determining a first waveform and a second waveform, the first waveform and second waveform related to a combined frequency spectrum and bandwidth associated with a geophysical survey line. Then, a signal is constructed by sequencing the first waveform with the second waveform. This signal may be utilized in a transmitter, which may be pulled by a vessel along the geophysical survey line.

Abstract: A vibration detection circuit. The circuit includes an accelerometer, a combining filter, an amplifier, and an analog to digital converter. The accelerometer generates one or more signals indicative of movement along an axis. The combining filter filters a component of the one or more signals not associated with movement and combines the components of the one or more signals indicative of movement to create a combined signal. The amplifier amplifies the combined signal and creates an amplified signal. The analog to digital converter converts the amplified signal into a digital value.

Abstract: An MR sensor arrangement is integrated with an IC. A metal layer of the IC structure (e.g. CMOS) is patterned to define at least first and second contact regions. Metal connecting plugs are provided below the first and second contact regions of the metal layer for making contact to terminals of the integrated circuit. A magnetoresistive material layer is above the metal layer and separated by a dielectric layer. Second metal connecting plugs extend up from the metal layer to an MR sensor layer. The sensor layer is thus formed over the top of the layers of the IC structure.

Abstract: Disclosed is a current sensor including magnetic sensors disposed on a conductor having at least two separated current-carrying areas with different current magnitudes and detecting a magnetic field generated according to currents flowing through the conductor and a controller controlling outputs of the magnetic sensors, wherein the magnetic sensors are disposed in at least two respective areas having different current magnitudes and the controller switches outputs of the magnetic sensors.