Abstract: A method for detecting a change in permeability of a magnetostrictive object due to a change in strain. At least one first coil and at least one second coil are obtained and positioned such that magnetic flux lines induced by an electric current in the first coil(s) pass through at least one portion of the object in a direction substantially parallel to the strain direction, such that magnetic flux lines induced by an electric current in the second coil(s) pass through at least one portion of the object in a direction substantially parallel to the strain direction, and such that any electromagnetic interference sensed by the first coil(s) is sensed oppositely by the second coil(s). The total inductance of the positioned first and second coil(s) is measured over time. A change in permeability of the object is detected from a change in the measured total inductance over time.

Abstract: An eddy current inspection apparatus includes a holder for a specimen, a holder for an eddy current probe, and an eddy current instrument operatively joined thereto. The probe holder includes carriages for translating the probe along first and second axes. The probe holder is selectively moved to align the probe with an internal channel of the specimen for sliding movement therealong to conduct eddy current inspection thereof.

Abstract: A detection system determines the position of an object moving along a first direction. The system includes a magnetic field source generating a magnetic field signal and a magnetic field detection system coupled to the object. The detection system includes a source interface module with magnetic field sensors positioned a known distance apart along a second direction different from the first direction. Each sensor detects the magnetic field generated by the magnetic field source and generates a magnetic field signal. A processing module processes the magnetic field intensity signal produced by the source interface module. The processing module generates data for each sensor in the source interface module, which is made up of points representing peak magnetic field and sensor location along the second direction. The points are compared to determine the distance of the object from the magnetic field source along the second direction.

Abstract: A magnetic sensor assembly measures changes in the position of a lever arm. The magnetic sensor assembly has a support. A lever arm can pivot about an axis of rotation or a pivot point and is attached to the support at a first end of the lever arm. A magnet produces a magnetic field adjacent the first end of the lever arm and is fixed to rotate in a predetermined arc about the pivot point or axis of rotation in response to a pivotal movement of the lever arm. A magnetic sensor is positioned in proximity to the magnet to detect changes in the magnetic field due to rotation of the magnet along a predetermined arc. Preferably the predetermined arc has a constant radius of curvature forming at least a portion of a circular arc. The magnetic sensor assembly preferably employs a magnet that is at least arcuate in shape more preferably the magnet is annular or penannular forming a ring.

Abstract: A device and method for mapping magnetic fields of a sample at a resolution less than the wavelength of light without altering the magnetic field of the sample is disclosed. A device having a tapered end portion with a magneto-optically active particle positioned at the distal end thereof in communication with a fiber optic for transferring incoming linearly polarized light from a source thereof to the particle and for transferring reflected light from the particle is provided. The fiber optic has a reflective material trapping light within the fiber optic and in communication with a light detector for determining the polarization of light reflected from the particle as a function of the strength and direction of the magnetic field of the sample.

Abstract: A single-axis, fluxgate magnetometer apparatus comprises: an excitation subassembly comprising a toroidal core wound with a predetermined number of turns of an excitation coil; and a pick up subassembly comprising a coil form including a hollow chamber, and a predetermined number of turns of a pick up coil wound on the coil form about the hollow chamber, the excitation subassembly disposed in the hollow chamber of the coil form and secured in the hollow chamber at a desired position. A method of adjusting the single-axis, fluxgate magnetometer apparatus comprises the steps of: applying an excitation signal to the excitation coil while disposed in the hollow chamber; monitoring a signal waveform of the pick up coil responsive to the excited excitation coil; adjusting the position of the excitation subassembly in the hollow chamber to effect a desired signal waveform of the pick up coil; and securing the excitation subassembly in the hollow chamber at the position that provides the desired signal waveform.

Abstract: A method characterizes a generally-trapezoidally-shaped portion of a writing pole of a perpendicular magnetic write head in proximity to a magnetic medium. The method includes providing measured track width data corresponding to magnetic track widths of a plurality of tracks written by the writing pole on a rotating magnetic medium underlying the writing pole. The magnetic track widths vary as a function of skew angle of the writing pole during writing. The method further includes determining a magnetic width of the wider of a leading edge and a trailing edge of the writing pole from a first portion of the measured track width data corresponding to a first range of skew angles. The method further includes determining at least one magnetic taper angle of the writing pole from the measured track width data.

Abstract: A hybrid speed and or proximity sensor may include a variable reluctance sensor with an added excitation circuit. Similarly, a hybrid speed and or proximity sensor may include a variable inductance proximity sensor having a magnet and a magnetically permeable pole piece added in the sensor. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: An angle detection apparatus for detecting an angle of a rotatable magnetic field source comprises first and second magnetic sensor units for detecting first and second magnetic components of the magnetic field of the magnetic field source, driving means for driving the first and second magnetic sensor unit and control means. The control means control an output signal of the first magnetic sensor unit so as to have a fixed value and the driving means drive the second magnetic sensor unit according to the same drive conditions as those applied to the first magnetic sensor unit at the time when the first magnetic sensor unit is controlled by said control means so that an output signal of the second magnetic sensor unit is proportional to the tangent of said angle.

Abstract: A method is described for determining a rotation speed and a rotation direction of a component (2), in particular a transmission output shaft, with a sensor device (1). In the sensor device (1), as a function of a rotation speed and direction of the component (2), a first sensor signal and a second sensor signal are generated, which are phase shifted relative to one another and each of which, on reaching an upper switching threshold or a lower switching threshold in the sensor device (1), triggers a switching signal. When there are alternating, consecutive switching signals of the two sensor signals, the sensor device (1) emits a pulse signal as a function of which a variation of a sensor signal is generated, which is used to determine a rotation speed of the component (2).

Abstract: Methods and systems for detecting a rotating target are disclosed herein, wherein a biasing magnet is associated with a rotating target in association with a dual peak detector. The rotating target generally comprises a plurality of teeth and at least one slot formed between at least one tooth of the rotating target. In general, the biasing magnet and the rotating target generate a magnetic signal having positive and negative peaks thereof. The dual peak detector includes a tooth detector and a slot detector, such that the dual peak detector detects a minimum and maximum peak of the magnetic signal generated by the biasing magnet and the rotating target. Additionally, a clamping circuit can be associated with the dual peak detector, wherein the clamping circuit can provide a true power on (TPO) functionality.

Abstract: A method for detecting the motion of an element relative to a sensor arrangement is proposed, wherein switching signals (1) are evaluated as a function of a pulse transmitter passing in front of the sensor, and a switching hysteresis (H) is adapted in the evaluation as a function of the values of the switching signal (1). When the element moves below a predetermined limiting value (fGrenz), a relatively great switching hysteresis (Hyst0) is set, and when the limiting value (fGrenz) is exceeded, a reduced switching hysteresis (H1) is set.

Abstract: Apparatus and method for positioning a power makeup/breakout device, commonly referred to as a “power tong unit,” along the longitudinal axis of a tubular, with respect to the end of a connection. A probe having an electric coil is mounted on the power tong. An alternating electric current is flowed through the coil, creating an electro-magnetic field emanating from the coil. Positioning the coil such that the tubular connection is within the magnetic field, then moving the coil such that the connection end moves within the magnetic field, permits the connection end to be seen as a discontinuity, by the principles of eddy current testing. The location of the connection end is used to manually position the tong, or is input to a processor and then to a power positioner, which properly positions the power tong with respect to the connection end.

Abstract: A method is provided for testing a magnetoresistive sensor for polarity reversal. In one embodiment, the method includes: writing a test pattern on a magnetic disk; providing a mechanical or thermal stress to the magnetoresistive sensor for a period of time; and, comparing the polarity of the test pattern before and after the application of stress.

Abstract: A method is disclosed for extracting information about a system of nuclear spins from a region of an earth formation. Specifically, a set of NMR data is acquired for a fluid sample located either in a borehole or in a laboratory environment. From the set of NMR data, a multi-dimensional distribution is calculated using a mathematical inversion that is independent of prior knowledge of fluid sample properties.

Abstract: A measuring assembly and machining assembly allowing for easy access and maintenance of the measuring assembly. The measuring assembly is disposed within a bushing to allow for easy removal of the measuring assembly. Furthermore, the machining assembly allows for access and maintenance of the measuring assembly with little or no disassembly of the machining assembly. Therefore, increased longevity and reduced maintenance of the measuring assembly is required during operation of the machining assembly.

Abstract: In a magnetic sensor device, a positioning element is provided with receptacles for receiving one magnetic field sensor element each. The positioning element and the magnetic field sensor elements are manufactured in a way that they fit exactly together so that the positioning element exactly positions the sensor elements with respect to each other. The magnetic field sensor elements may be manufactured separately before they are put together to build the magnetic field sensor device.

Abstract: The invention finds application in the field of electric valve actuators. Particularly, the invention relates to a magnetic absolute angular position sensor for valves controlled by electric part-turn actuators, wherein the rotation ? of the valve shaft (10) induces a change in the direction along which the lines of the magnetic field generated by a magnet (8) integral therewith, pass through a stationary circuit board (7), containing two Wheatstone bridges arranged at 45° to each other, and made of a magneto-resistive material. Hence, two 90° electric signals X and Y are generated, having the same amplitude, which allow to uniquely determine the angle of rotation ? of the shaft (10).

Abstract: An objective is to perform malfunction diagnosis such as a wire breakage of resolver windings using a simple circuit configuration, realize the cost down and reliability improvement for resolver malfunction diagnostic circuits, and reduce electric-power consumption in the resolver malfunction diagnostic circuits. A resolver malfunction diagnostic circuit includes a resolver-signal inputting circuit for, in response to rotation of a rotor, receiving signals from a resolver that outputs from its output winding rotational-angle signals corresponding to the rotor rotational angle, and the output winding is determined to be out of order when the amplitude of the output from the output winding is equal to or lower than a predetermined value, and a deviation between the center voltage of its output voltage and the center voltage in the normal operating state exceeds an allowable level.

Abstract: A motorcycle mileage counter inductor is constructed to include a magnetic device holder mounted in the outer end of the tubular color of the wheel set of a motorcycle's front wheel, an annular magnetic device mounted on the magnetic device holder, the annular magnetic device having a plurality of magnets alternatively abutted against one another in reversed directions, and a sensor formed of a Hall chip and mounted in a cover shell being affixed to the front fork of the motorcycle around the outer end of the tubular collar and electrically connected to the mileage counter and ABS (anti-locking brake system) of the motorcycle through a signal line for detecting the amount of rotation of the motorcycle's front wheel and providing a signal indicative of the amount of rotation of the motorcycle's front wheel to the mileage counter and ABS of the motorcycle.