Abstract: A structure and method are provided for self-test of a Z axis sensor. Two self-test current lines are symmetrically positioned adjacent, but equidistant from, each sense element. The vertical component of the magnetic field created from a current in the self-test lines is additive in a flux guide positioned adjacent, and orthogonal to, the sense element; however, the components of the magnetic fields in the plane of the sense element created by each of the two self-test current line pairs cancel one another at the sense element center, resulting in only the Z axis magnetic field being sensed during the self-test.

Abstract: The computer implemented method, system or computer program product comprises collecting magnetometer data from the device; and calculating a center of a shape of the magnetometer data as a result of minimization. The minimization of calculating the center of the shape further comprises calculating a plurality of running sums of the magnetometer data; storing the plurality of running sums; storing a count of the number of terms in each of the running sums; and calculating the center of the shape and setting the estimated magnetometer bias to the center of the shape. The radius of the sphere is calculated to ensure accuracy in the estimator of the magnetometer bias.

Abstract: An energy converter includes a magnetism generation mechanism unit that generates a magnetic field when connected to an AC electrical power source, and a rotating mechanism unit having a single turn coil array member in which a plurality of single turn coils is disposed at a predetermined interval and a soft magnetic metal plate disposed on a side of the single turn coil array member opposite to the magnetism generation mechanism unit. The rotating mechanism unit is structured such that the single turn coil array member faces the magnetism generation mechanism unit across a predetermined magnetic gap and rotary driven by the magnetic field. Here, a drive signal period of the electrical power source is a period that maximizes an eddy current generated in the soft magnetic metal plate.

Abstract: In a process for testing the measurement accuracy of at least one magnetic field sensor, in particular during manufacturing, a semiconductor wafer that has at least two semiconductor chips is provided. A measurement coil is integrated into at least one first semiconductor chip, and a magnetic field-sensitive electric circuit is integrated into at least one second semiconductor chip that forms the magnetic field sensor. The first semiconductor chip, of which at least one is present, is positioned at an exciter coil that is supplied with current in order to generate a reference magnetic field. With the aid of the measurement coil a first measured value that is dependent on the magnetic flux density is acquired and the current in the exciter coil is adjusted depending on the first measured value. The second semiconductor chip, of which at least one is present, is positioned at the exciter coil.

Abstract: A dynamically self-adjusting magnetometer is disclosed. In one embodiment, a first sample module periodically generates an electronic signal related to at least one magnetic field characteristic of a monitored environment. A second sample module periodically generates an electronic signal related to at least one magnetic field characteristic of a monitored environment. A summing module sums the absolute value of the electronic signal from the first sample module and the electronic signal from the second sample module. A delta comparator module receives the electronic signals from each of the first sample module, the second sample module and the summing module and compares each of the electronic signals with a previously received set of electronic signals to establish a change, wherein an output is generated if the change is greater than or equal to a threshold.

Abstract: A method for calibration of a thickness gauge is provided in which the thickness gauge measures the thickness of a measured object in a stipulated measurement direction with at least one displacement sensor, operating contactless or by scanning, a reference object with known thickness and shape being brought into at least one partial area of the measurement field of the at least one displacement sensor.

Abstract: Disclosed is an eddy current non-destructive inspection device which includes an eddy current probe with a probe conductor resistance dynamically changing due to operation conditions, such as temperature. The device further includes a signal generating circuit generating an inspection frequency signal and a low frequency signal. Sensed inspection frequency signals are processed to produce resulting signals with possible drift. A low frequency processing circuit includes a resistance calculator producing a substantially true value of the dynamic probe resistance, based on which compensation operations are configured to correct the drifted resulting signals and produce corrected resulting signals.

Abstract: A magnetic field sensor includes a diagnostic circuit that allows a self-test of most of or all of, the circuitry of the magnetic field sensor, including a self-test of a magnetic field sensing element used within the magnetic field sensor. The magnetic field sensor can generate a diagnostic magnetic field to which the magnetic field sensor is responsive.

Abstract: Methods and apparatuses are provided for creation of discrete corrosion defects with a wide range of diameter to depth aspect ratios for painted test standards. Also provided are methods for use of those test standards to characterize the corrosion under paint detection threshold, statistical reliability, and accuracy of NDI and/or NDT techniques including but not limited to flash thermography, ultrasonic testing, eddy current testing, microwave testing, shearography, and infrared testing.

Abstract: A method for measuring current in an electric network comprising at least one first electric line. The method includes fitting the first line with a circuit breaker having a protection coil and having a wall traversed by a magnetic field emitted by the protection coil; arranging on the wall of the circuit breaker a synchronous three-axis digital magnetometer on a semiconductor chip; by way of the digital magnetometer, measuring at least one component of a magnetic field emitted by the coil; and determining the value of a current traversing the electric line from the measured component.

Abstract: A method and apparatus eliminate magnetic domain walls in a flux guide by applying, either simultaneously or sequentially, a current pulse along serially positioned reset lines to create a magnetic field along the flux guide, thereby removing the magnetic domain walls. By applying the current pulses in parallel and stepping through pairs of shorter reset lines segments via switches, less voltage is required.

Abstract: A magnetic sensor apparatus includes a substrate, a plurality of magnetoresistance sensor units, a reset coil and a compensation coil. The magnetoresistance sensor units are disposed on the substrate. The reset coil is disposed over the magnetoresistance sensor units. The reset coil is used for introducing a resetting current. The compensation coil is disposed over the magnetoresistance sensor units. The compensation coil is used for introducing a compensating current. A wiring pattern of the compensation coil includes a first spiral portion and a second spiral portion in opposite spiral directions.

Abstract: A magnetic sensor apparatus includes a substrate, a plurality of magnetoresistance sensor units, a reset coil and a compensation coil. The magnetoresistance sensor units are disposed on the substrate. The reset coil is disposed over the magnetoresistance sensor units for introducing a resetting current, and a magnetic field generated from this resetting current can be used to reset magnetization directions of the magnetoresistance sensor units. The reset coil includes a plurality of first main segments. The compensation coil is disposed over the magnetoresistance sensor units for introducing a compensating current, and another magnetic field generated from the compensating current is used as a compensation magnetic field onto the magnetoresistance sensor units. The compensation coil includes a plurality of second main segments. The first main segments of the reset coil are perpendicular to the second main segments of the compensation coil.

Abstract: A magnetic sensor apparatus includes a substrate, a plurality of magnetoresistance sensor units, a compensation coil and a reset coil. The magnetoresistance sensor units are disposed on the substrate. The compensation coil is disposed over the magnetoresistance sensor units. The compensation coil is used for introducing a compensating current. The reset coil is disposed over the magnetoresistance sensor units. The reset coil is used for introducing a resetting current. The resetting current is used for resetting the magnetoresistance sensor units. The reset coil has a plurality of notch structures located at turning portions of the reset coil.

Abstract: Methods and apparatus employing non-magnetometer navigational sensor data to assist in determining whether a change in a magnetic field detected by a magnetometer is likely due to a source of internal or external magnetic interference, and more generally, whether such interference is likely to be persistent or transient. If the magnetic field data detected by the magnetometer indicates a large change in magnetic field, but the non-magnetometer navigational sensor (e.g., gyroscope) data does not indicate a corresponding change in orientation of the mobile device contemporaneous with the change in magnetic field, then the cause of the magnetic field change may be determined as likely originating from a localized external interference source and the device may prompt the user to move away from the interference source, rather than initiating a recalibration of the magnetometer.

Abstract: Provided are apparatus and methods for compensation of mechanical imbalance in a measurement apparatus, that provides options for increased accuracy and/or less expensive manufacture of a torsion balance. Orientation measurements are taken and an imbalance torque about the torsion spring's axis of rotation is determined, and used to calculate a compensation. The measurement apparatus of one embodiment includes a test body and a set of magnets for generating a first disturbing force on the test body in response to a paramagnetic gas. A conductor element in the magnetic field receives an electrical current that generates a second opposing force to the test body, under feedback control that varies the current until the test body achieves a balanced null position. The control signal required to achieve the fixed null position is measured.

Abstract: A method for determining the position and/or change of position of a measured object relative to a sensor, where the sensor preferably has a sensor coil to which an alternating current is applied, is characterized in that a magnet associated with the measured object, in a soft magnetic foil, whose permeability changes under the influence of a magnetic field on the basis of the magnetic field's field strength and which is arranged in the area of influence of the sensor, brings about a change in the permeability of the foil and in that the change in the permeability of the foil is determined from the latter's reaction to the sensor, and this is used to determine the position and/or change of position of the measured object relative to the sensor. A sensor arrangement is designed accordingly.

Abstract: A system and method for estimating the state-of-charge (SOC) of a battery cell in a vehicle using a magnetic sensor that measures changes in magnetism of the battery cell. The method provides an offset correction to a current output signal from the magnetic sensor that calibrates the current output signal to a known magnetic field strength, provides a temperature correction to the current output signal that corrects the current output signal based on a temperature of the magnetic sensor, and provides a current correction to the current output signal that removes portions of the magnetic field caused by other battery cells, where the corrected current output signal is converted to the battery cell SOC.

Abstract: The gauss meter devices of the present invention are small, low power 3 axis field monitor board which detects DC to slow varying magnetic fields. The unit is designed to be embedded into a system which may be sensitive to magnetic fields and needs to continuously measure the magnitude of the field around it. The unit continuously monitors and logs magnetic fields on X, Y and Z axes and it also logs the vector summation of the X, Y and Z axes. The unit may be controlled and queried by wired serial communication means or by means of an integrated radio frequency (RF) transceiver. The RF transceiver may utilize a proprietary communication protocol or a standard wireless communication protocol such as ZigBee, Bluetooth or any of the IEEE communications standards. The many configuration settings of the device may be changed by the user by issuing commands to the device from an established command set.

Abstract: A magnetic field sensor includes built in self-test circuits that allow a self-test of most of, or all of, the circuitry of the magnetic field sensor, including self-test of a magnetic field sensing element used within the magnetic field sensor, while the magnetic field sensor is functioning in normal operation.

Abstract: Methods and apparatuses are provided for creation of discrete corrosion defects with a wide range of diameter to depth aspect ratios for painted test standards. Also provided are methods for use of those test standards to characterize the corrosion under paint detection threshold, statistical reliability, and accuracy of NDI and/or NDT techniques including but not limited to flash thermography, ultrasonic testing, eddy current testing, microwave testing, shearography, and infrared testing.

Abstract: A system and method of obtaining magnetometer readings for performing a magnetometer calibration are provided. The method comprises detecting initiation of a magnetometer calibration; displaying a plurality of visual elements representing at least a pair of movements, each of the movements orienting a device comprising the magnetometer in substantially opposite positions along a respective axis; and obtaining at least one magnetometer reading during movement of the device. The visual elements may include one in an upright position, one in an upside down position, one facing a first direction and one illustrating the device facing in a second direction. A path may also be defined between the plurality of visual elements using one or more arrows.

Abstract: Magnetic field sensor including a magnetic field sensing circuit (2) comprising a reference magnetic field generator (8) and a magnetic field sensing cell (6), and a signal processing circuit (4) connected to the output of the magnetic field sensing cell and comprising a demodulator circuit and a gain correction feedback circuit (30, 28, 47) for correcting error fluctuations in the transfer characteristic of the magnetic field sensor. The sensor further comprises a reference current generator (3) configured to generate a reference current I ref, the reference current generator connected to the magnetic field sensing circuit (2) configured for generating the reference magnetic field B ref and to the gain correction feedback circuit configured for providing a reference signal (yref) to which an output signal of the demodulator circuit may be compared.

Abstract: An apparatus for detecting a decrease in air pressure of a tire attached to a vehicle includes a rotation speed detection means for periodically detecting rotation speeds of tires of respective wheels of the vehicle; a rotation wheel speed ratio calculation means for calculating a rotation wheel speed ratio between front wheels and rear wheels of the vehicle; a wheel torque calculation means for calculating a wheel torque of the vehicle; an initialization means for obtaining a relation at a normal internal pressure between the wheel torque and the rotation wheel speed ratio; a comparison means for comparing the rotation wheel speed ratio with the rotation wheel speed ratio at a normal internal pressure obtained from the wheel torque and the relation; and a determination means for correcting the comparison result by a front-to-rear direction acceleration and determining whether there is a tire having a decreased air pressure or not.

Abstract: A system includes an object in a space to generate an induced field; coils that generate a driving field; a detecting coil that detects a synthetic field of the driving field and the induced field; a unit that detects a driving current through the coil in synchronization with field detection by the detecting coil; a calculating unit that calculates a position and a direction of the object based on a detection value of the synthetic field and a detection value of the driving current; and a unit that calculates a phase of a driving field component which corresponds to the driving field at the detection value of the synthetic field, based on the detection value. The calculating unit obtains a component having a phase difference approximately orthogonal to the phase of the driving field component and calculates the position and direction of the object based on the obtained component.

Abstract: An apparatus for the nondestructive measurement of materials that includes at least two layers of electrical conductors. Within each layer, a meandering primary winding is used to create a magnetic field for interrogating a test material while sense elements or conducting loops within each meander provide a directional measurement of the test material condition. In successive layers extended portions of the meanders are rotated so that the sense elements provide material condition in different orientations without requiring movement of the test circuit or apparatus. Multidirectional permeability measurements are used to assess the stress or torque on a component. These measurements are combined in a manner that removes temperature effects and hysteresis on the property measurements. This can be accomplished through a correction factor that accounts for the temperature dependence.

Abstract: A clamping current and voltage sensor provides an isolated and convenient technique for measuring current passing through a conductor such as an AC branch circuit wire, as well as providing an indication of an electrostatic potential on the wire, which can be used to indicate the phase of the voltage on the wire, and optionally a magnitude of the voltage. The device includes a body formed from two handle portions that contain the current and voltage sensors within an aperture at the distal end, which may be a ferrite cylinder with a hall effect sensor disposed in a gap along the circumference to measure current, or alternatively a winding provided through the cylinder along its axis and a capacitive plate or wire disposed adjacent to, or within, the ferrite cylinder to provide the indication of the voltage. When the handles are compressed the aperture is opened to permit insertion of a wire for measurement.

Abstract: Double modulation of a magnetoresistive sensor entails modulating both an excitation (e.g., voltage or current) applied to the sensor and a tickling magnetic field applied to the sensor. The excitation and magnetic field are modulated at different frequencies fc and ff, respectively. As a result of the double modulation, the sensor output spectrum includes a carrier tone (CT) at frequency fc and side tones (STs) at frequencies fc±ff. A baseline relation between CT amplitude and ST amplitude is determined (e.g., by measuring CT and ST amplitude while drift occurs in the absence of a sample). During sensor operation, raw ST measurements are corrected using corresponding raw CT measurements to provide corrected ST measurements as the sensor output.

Abstract: In general, the disclosure is directed to techniques for determining the position of a piston within a linear actuator, such as a hydraulic cylinder, in a more cost effective and less labor-intensive fashion compared to current techniques for determining the position of a piston within a linear actuator. One or more magnets may be operably coupled to the piston, and a linear array of sensors may be disposed along an exterior length of the linear actuator. The sensors may measure the magnetic field generated by the magnet and, based on the measured magnetic field, may determine the location of the piston within the linear actuator.

Abstract: In determining an exciter conductor spacing of an exciter conductor of an exciter conductor structure from a sensor element of a calibratable magnetic field sensor, first and second electric currents are impressed into the first and second exciter conductors of the exciter conductor structure to generate first and second magnetic field components in the sensor element of the magnetic field sensor, and a quantity is determined depending on the first and second magnetic field components by means of the sensor element. Further, the exciter conductor spacing of the exciter conductor from the sensor element of the magnetic field sensor is established in dependence on an exciter conductor intermediate spacing between the first exciter conductor and the spaced-apart second exciter conductor and the quantities depending on the first and second magnetic field components.

Abstract: In a sensor of a sensor unit in which working voltage or calibration voltage is supplied through a single input end, working voltage can be stably supplied to the sensor after initial calibration. The sensor unit includes a voltage stabilizing circuit for stabilizing a voltage value of a supply power source to said working voltage, and a wiring for supplying said calibration voltage to the sensor, which are provided parallel to each other between the input end of the sensor and a power source connecting end for the sensor on the circuit board, and a switching portion which can disconnect the wiring, wherein an access hole is formed in the housing through which the switching portion is accessible to disconnect the wiring.

Abstract: An integrated circuit (IC) current sensor that self-calibrates to adjust its signal gain when employed in a current divider configuration is presented. The current sensor includes an integrated current conductor, a magnetic field transducer, a controllable gain stage and a calibration controller. The integrated current conductor is adapted to receive a portion of a calibration current. The calibration current corresponds to a full scale current. The magnetic field transducer, responsive to the calibration current portion, provides a magnetic field signal having a magnitude proportional to a magnetic field generated by the calibration current portion. The controllable gain stage is configured to amplify the magnetic field signal with an adjustable gain to provide an amplified magnetic field signal.

Abstract: A magnetic field sensor and a method associated with the magnetic field sensor provide gain correction coefficients and/or offset correction coefficients stored in the magnetic field sensor in digital form. The gain correction coefficients and/or offset correction coefficients can be used to generate analog control signals to control a sensitivity and/or an offset of an analog signal path through the magnetic field sensor.

Abstract: A Superconducting Quantum Interference Device (SQUID) magnetic sensor system and method can image organic transplant condition, such as status, acceptance, or rejection, in-vivo. This represents a major advane in transplant imaging technology with a new market for biomagnetic sensor devices. In-vivo transplant condition determination provides a greater range of imaging methodologies over existing methods in sensitivity, and enables early detection of rejection with the ability to determine the need for anti-rejection drugs.

Abstract: A calibrating method for a portable electronic device having azimuth device such as an electronic compass is disclosed. The calibrating method can be achieved by checking at least one sensor in the portable device incorporating the electronic compass configured in the portable device, so as to effectively detect and verify a temporary abnormal magnetic field caused by a stylus movement. When the electronic compass detects an abnormal magnetic field, the operation status of the sensor is checked for any change existence. If the operation status of the sensors changes, the abnormal magnetic field is verified as a temporary magnetic filed due to the movement of the stylus, in which case the electronic compass passes the calibration and goes on detecting the geomagnetic field according to its default setting value.

Abstract: A system including magnetic sensing elements and a circuit. The magnetic sensing elements are configured to sense a magnetic field that is generated via a current and to provide signals that correspond to the magnetic field. The circuit is configured to determine calibration values based on the signals and measure the current based on the signals.

Abstract: A magnetoresistance sensor includes a multifunctional circuit structure having the functionality of built-in self-testing and/or device configuration. The magnetoresistance sensor further includes a substrate having a first dielectric layer formed thereon and a magnetoresistance structure. The multifunctional circuit structure is disposed on the dielectric layer and includes a winding structure for generating a magnetic field for testing and configuring the magnetoresistance sensor. The magnetoresistance structure is disposed on the multifunctional circuit structure, wherein a topmost layer of the magnetoresistance structure includes a magnetoresistance layer, and the magnetoresistance structure generates electrical resistance variance corresponding to the generated magnetic field for testing and configuring the magnetoresistance sensor. A method for manufacturing the magnetoresistance sensor is also provided.

Abstract: Described are embodiments to ensure that the equipment utilized to detect antigens is reliable and accurate. Accordingly, one embodiment of the invention includes a calibration assembly having nanoparticles, with known magnetic properties, spaced apart at known y-axis locations along the calibration assembly. In one embodiment, the calibration assembly may be used to calibrate a matched filter of the write and read circuitry. Because the calibration assembly comprises nanoparticles with known magnetic properties the read response of the read circuitry to a particular nanoparticle may be stored in the matched filter as an ideal signal for that nanoparticle. The ideal signal stored in the matched filter may then be utilized for reliably and accurately detecting antigens.

Abstract: Measurements made with a multicomponent logging system oriented in a horizontal position above the surface of the earth must satisfy certain relationships. These relationships are used to establish calibration errors in the system.

Abstract: A magnetic field sensor includes a reference-field-sensing circuit channel that allows a calibration or a self-test of the circuitry of the magnetic field sensor. The magnetic field sensor can generate a reference magnetic field to which the magnetic field sensor is responsive.

Abstract: An assembly is provided comprising a member having a graduated edge that varies in radius with respect to an axis, and a sensor adjacent to the graduated edge, the member and the sensor are capable of rotating relative to one another. The sensor provides a signal level proportional to a distance between the sensor and the graduated edge, and the distance, between the sensor and the graduated edge, is indicative of a rotation angle of the member relative to the sensor.

Abstract: A circuit to detect a movement of an object has a calibration time period that ends when peak detectors in the circuit stop updating for a predetermined amount of time. A method associated with the circuit is also described.

Abstract: An exemplary current sensor operating in accordance with the principle of compensation includes a primary winding creating a magnetic field based on a current to be measured, a secondary winding generating a magnetic field compensating the primary winding based on a compensation current. The current sensor also includes a magnetic core, a terminating resistor connected in series to the secondary winding, and sensor means. A booster circuit is connected downstream of the sensor means and feeds the compensation current to the secondary winding via the terminating resistor. The booster circuit includes a switched mode amplifier with a pulse width and density modulator that operates based on pulse width and density modulation, turning the compensation current into a pulse width and density modulated current. The switched mode amplifier having a switching frequency that is high at when the compensation current is small and low when the compensation current is high.

Abstract: An accessory device for a field transmitter comprising an enclosure housing an electronic processing unit. Said device comprises a portable supporting body removably couplable with the transmitter and on which there are provided at least one activation unit which can be operated by a user, and an electronic processing circuit which is operatively interlocked with said activation unit and is suitable to be operatively connected to the electronics of the transmitter so as to transmit one or more signals thereto following actuation of the activation unit.

Abstract: Described herein are systems, devices, and methods that provide a stable magnetometer. The magnetometer includes a drive element that facilitates flow of a drive current through a node and a sense element operable to detect a magnetic field operating on the drive current. To reduce offset in the detection of the magnetic field, a voltage detector, electrically coupled to the drive element through the node, determines a variation between a node voltage and a target voltage. The voltage detector facilitates suppression of the variation and thereby minimizes the offset in the sense element.

Abstract: Systems and methods for performing a self-test on a sensing device are described in the present disclosure. One implementation, among others, includes a method of performing a self test. In this implementation, the method includes supplying a periodic magnetic field upon a sensing element that is configured to sense a parameter of an object. The method further includes receiving an output from the sensing element indicating the operability of the sensing element. It should be noted that the output is received independently of the parameter of the object.

Abstract: Embodiments of the invention described herein provide a magnetic sensor interface capable of adjusting signal conditioning dynamically such that the true positive and negative peaks of the input signal are maintained for a given target across its entire speed range (0-Max rpm), therefore increasing the signal to noise ratio at low speeds and avoiding clipping or distortion at high speeds. In one aspect, a method comprises receiving an alternating differential voltage signal from a sensor. The alternating differential voltage signal has an amplitude that changes over time. The alternating differential voltage signal is converted to an attenuated single-ended voltage signal that can be dynamically scaled. The attenuated single-ended voltage signal can be scaled by multiplying the attenuated single-ended voltage signal by a scaling factor. The scaling factor is selected relative to a signal-to-noise ratio of the scaled attenuated single-ended voltage signal.

Abstract: Manufacturing of magnetometer units (20?) employs a test socket (41) having a substantially rigid body (43) with a cavity (42) therein holding an untested unit (20) in a predetermined position (48) proximate electrical connection (50) thereto, wherein one or more magnetic field sources (281, 332, 333, 334, 335, 336) fixed in the body (43) provide known magnetic fields at the position (48) so that the response of each unit (20) is measured and compared to stored expected values. Based thereon, each unit (20) can be calibrated or trimmed by feeding corrective electrical signals back to the unit (20) through the test socket (41) until the actual and expected responses match or the unit (200) is discarded as uncorrectable. In a preferred embodiment, the magnetic field sources (281, 332, 333, 334, 335, 336) are substantially orthogonal coil pairs (332, 333, 334) arranged so that their centerlines (332-1, 333-1, 334-1) coincide at a common point (46) within the predetermined position (48).

Abstract: An apparatus and a general method to measure a magnetic field using magneto-resistive sensors in an open-loop configuration are disclosed. A key feature is the regular in-situ normalization of the sensors to compensate for the effects of sensor aging.

Abstract: A method and system are provided for calibrating a magnetometer of a mobile device. The method comprises displaying a visual indication of a gestural path on a display of the portable electronic device, monitoring for changes in orientation of the portable electronic device, changing the visual indication in response to the monitored changes in the orientation of the portable electronic device, measuring a magnetic field with the magnetometer, and calibrating the magnetometer in accordance with measurements of the magnetic field acquired at different points along the gestural path.