Abstract: Apparatus for detecting a passing magnetic article includes a peak detector providing a detector output signal that changes state when the magnetic field signal differs from a magnetic field tracking signal by more than a threshold offset amount. The threshold offset amount is dynamically variable in response to detection of a speed of rotation of the magnetic article and a peak-to-peak signal level of the magnetic field signal.

Abstract: A method for tracking a position of an object includes using a field sensor associated with the object to measure field strengths of magnetic fields generated by two or more field generators, wherein a measurement of at least one of the field strengths is subject to a distortion. Rotation-invariant location coordinates of the object are calculated responsively to the measured field strengths. Corrected location coordinates of the object are determined by applying to the rotation-invariant location coordinates a coordinate correcting function so as to adjust a relative contribution of each of the measured field strengths to the corrected location coordinates responsively to the distortion in the measured field strengths.

Abstract: A cost-effective system provides reliable location information for locating a vehicle tied to a guideway. Reference markers are mounted to the guideway and scanning devices are disposed in the vehicle and generate at least one output signal when they pass a reference marker. The scanning devices are formed from several individual sensors which are extended in the driving direction with an average scanning length equal to or greater than a distance between neighboring reference markers.

Abstract: A disclosed electromagnetic survey system includes one or more streamer(s) having multiple electromagnetic sensors and motion sensing units. Each motion sensing unit has one or more accelerometer(s) to measure motion perpendicular to an axis of the streamer, and a rotation sensor to measure rotation about the axis. The measurements of the accelerometer are adjusted based on measurements from the rotation sensor. The survey system also includes one or more processor(s) that determine, for each electromagnetic sensor, a motion signal based on the adjusted measurements. A described electromagnetic survey method includes processing acceleration and rotational motion measurements to obtain an orientation of motion sensing units as a function of time. The measured acceleration is manipulated based on the orientation to obtain one or more velocity signal(s) for each motion sensing unit. Interpolation is performed on the velocity signals to determine at least one velocity signal for each electromagnetic sensor.

Abstract: A method for tracking a position of an object includes using a field sensor associated with the object to measure field strengths of magnetic fields generated by two or more field generators, wherein a measurement of at least one of the field strengths is subject to a distortion. Rotation-invariant location coordinates of the object are calculated responsively to the measured field strengths. Corrected location coordinates of the object are determined by applying to the rotation-invariant location coordinates a coordinate correcting function so as to adjust a relative contribution of each of the measured field strengths to the corrected location coordinates responsively to the distortion in the measured field strengths.

Abstract: A position detector having a plurality of sensor units is used. Each of the sensor units is configured to determine positions. The sensor units are selectively used for outputting positions of a moving object. Positional outputs are generated by combining outputs from a plurality of the sensor units in a segment where the plurality of sensor units output positions together, for allowing the positional outputs to change continuously from a start to an end of the segment.

Abstract: A circuit arrangement for analysis and compensation of the signals for an inductive displacement sensor is provided. The circuit includes a first operating amplifier, a second operating amplifier and a coil for a displacement measurement, in parallel with the second operating amplifier output and the second operating amplifier first input and connected to a capacitance in series with the coil inductance and coil resistance to form an RLC series tuned circuit. In order to improve the accuracy of a measured resonance frequency, the circuit arrangement can be extended with a second coil for a temperature compensation, by connecting a first of the ends of the coil winding to a second end of the coil winding of the first coil and a second of the ends of the coil winding to the second input of the first operating amplifier.

Abstract: A sensing assembly. The sensing assembly is spaced apart from a magnet that has a magnet length, and includes a compensation module and a string of magnetic sensors that has a string length. The magnetic sensors are grouped into a plurality of magnetic sensor groups. Each of the magnetic sensors generates a respective intermediate signal based on the magnet. The compensation module assigns a plurality of respective gains to the respective magnetic sensor groups based on a difference between the magnet length and the string length, and applies the respective gains to the respective intermediate signals of the respective magnetic sensor groups to generate respective adjusted signals.

Abstract: An inductive sensor or detector includes as its sensitive element, preferably defining a front working plane of the sensor, a coil system forming an air-core transformer arrangement with a primary coil or winding (2) and a secondary coil or winding (3). The primary coil or winding of the system is associated with a capacitive component (4) in order to constitute a LC oscillating circuit whose oscillation is sustained by an adapted generator (5) in the form of an operational amplifier (6) and an associated resistance arrangement (R, R5, R13). The sensor also includes a signal processing circuit, for example signal adding (8), amplifying, converting (9) and/or evaluating circuits (10), fed by at least one signal provided by at least one component of the coil system. The inductive sensor comprises a direct or indirect feedback line (11) from the secondary coil or winding (3) to the input of the operational amplifier (6) of the generator (5).

Abstract: Assessment apparatus is provided, including a set of one or more radiators, which is adapted to generate an energy field at at least one fundamental frequency. A receiving sensor is adapted to generate a first signal responsive to the energy field when an interfering article is at a first location relative to the receiving sensor, and is adapted to generate a second signal responsive to the energy field when the interfering article is at a second location relative to the receiving sensor. A control unit is adapted to (a) receive and analyze the first and second signals, in order to compute a fingerprint signal characteristic of the interfering article, and (b) store, in a database, data indicative of the fingerprint signal, in association with an identity of the interfering article.

Abstract: Disclosed is a device for sensing the opening degree of a valve, which can easily determine the upper and lower limits without using upper and lower limit switches so that, besides simplifying the mechanical structure, the device can be easily installed, maintained, and repaired. The device can avoid basic errors and improve the opening degree sensing performance without using upper and lower limit switches, cams, and a spline so that, by simplifying the mechanical structure, the device can be manufactured, installed, maintained, and repaired at a low cost, and its long-term durability is improved. The device has a main gear adapted to disengage from the meter gear when the main gear is rotated excessively so that any damage to the meter gear and potentiometer, which may occur during installation or use, is prevented.

Abstract: Methods and systems for detecting an angular position of an electric motor are disclosed, including sending an electrical pulse through a stator coil of the electric motor, determining an approximate angular position of a rotor of the electric motor in response to detecting an timing of a returning electrical pulse from the stator coil, the timing of the returning electrical pulse being indicative of the angular position of the rotor; and determining an accurate position of the rotor in response to sensing a transition of a digital sensor in response to the rotor rotating relative to the stator, the transition being indicative of the accurate position.

Abstract: An electromagnetic tracking method includes generating an electromagnetic field (14) in a region of interest (16). The electromagnetic field is subject to distortion in response to a presence of metal artifacts proximate the electromagnetic field. An array of reference sensors (30,50,102,104,110) having a predefined known configuration are disposed proximate the region of interest. A first set of locations of the array of reference sensors is determined with respect to the electromagnetic field generator (12) in response to an excitation of one or more of the reference sensors via the electromagnetic field. A second mechanism (28), other than the electromagnetic field, determines a first portion of a second set of locations of at least one or more sensors of the array of reference sensors with respect to the second mechanism, the second mechanism being in a known spatial relationship with the electromagnetic field generator.

Abstract: A position detector arrangement for detecting a position of a packaging material with magnetic marking comprises a sensor assembly comprising a plurality of magnetic sensor units each comprising an output providing an output signal. The magnetic sensor units are arranged in at least two sensor unit pairs, with the sensor units of each pair arranged with opposite sensitivity directions, and with the sensor units arranged to sense magnetic markings of the packaging material. A signal processing assembly is connected to the outputs of the magnetic sensors and comprises a combiner arranged to aggregate the output signals of the sensors to an aggregated signal; and a detector arranged to determine the position of the packaging material from the aggregated signal. Further, a method for detecting a position of a packaging material with magnetic markings is disclosed.

Abstract: A digital based two wire proximity transmitter system and a method for calibrating the system, wherein the transmitter includes a customized linearization table uniquely generated during calibration to take into account the unique impedance properties of a particular probe/coaxial cable configuration. During calibration, the probe is positioned adjacent a calibration target. The calibration target is selected to have the same material characteristics as the target to be monitored during actual operation of the transmitter in the field. At a fixed distance between the probe and calibration target, the resonant frequency of the probe/cable system is determined. Thereafter, utilizing this resonant frequency to excite the probe, the voltage response of the probe/cable system is determined as the distance between the probe and the target material is incrementally changed.

Abstract: A position detecting circuit provided in an imaging apparatus having an optical system that images a subject image, an imaging element that performs photoelectric conversion of the subject image, and a release switch capable of setting states of two stages includes: a plurality of magnetic field change detecting elements that detect the intensity of a magnetic field formed by a magnetic field generating body attached to either the optical system or the imaging element and that are provided so as to be separated from each other; a position detecting portion that detects the position of the magnetic field generating body on the basis of outputs from the plurality of magnetic field change detecting elements; and a standby portion that stops a function of at least one of the position detecting portion and the plurality of magnetic field change detecting elements until a first stage of the release switch is set.

Abstract: Apparatus for assessing field distortion includes a probe and a processor. The probe includes a mechanical fixture for placement at a location to be tested, and one or more field generators, which are attached to the mechanical fixture and are arranged to generate respective magnetic fields. The probe further includes one or more field sensors, which are attached to the mechanical fixture at known positions with respect to the one or more field sensors and are arranged to sense the magnetic fields generated by the one or more field generators and to output signals responsively to the sensed magnetic fields. The processor is arranged to process the signals so as to assess a distortion of the magnetic fields sensed by the field sensors at the tested location.

Abstract: A method for initializing a rotational angle detector detecting rotational angles of two driven gears mated with a drive gear, rotated integrally with a detection subject, and obtaining rotational angle of the detection subject from the detected rotational angles. The method includes obtaining a first error and second error in each rotational angle of the driven gears when the drive gear is rotated in forward and rearward directions, obtaining an average value of the first and second errors, obtaining a difference between the average value and a theoretical rotational angle for the two driven gears when the rotational angle of the drive gear is 0°, and storing the difference as correction data added to each actual rotational angle of the two driven gears when obtaining the rotational angle of the detection subject.

Abstract: The invention relates to a device and a method for correction of the position (x) of a field sensor (4) measured by means of a magnetic localization device. External field distortions, such as caused for example by the rotating components (1a, 1b) of a computer tomograph (1), are then determined with the help of reference sensor (3) placed at a known position. It is possible to deduce, for example, the current angle of rotation (?) of the computer tomograph (1) from the measurement signals of the reference sensor (3). Based on an empirically determined correction (?(x, ?)), the uncorrected determined positions (x) of the field sensor (4) can then be converted to corrected positions (x?) in relation to the field distortions. The field generator (2) and the reference sensor (3) are preferably fastened to the gantry in order to eliminate the dependency of the field distortions on an inclination of the gantry.

Abstract: An eddy current type sensor for detecting a conductor includes a LC circuit and an oscillator. The LC circuit has a coil and a capacitor connected in parallel with the coil. The oscillator supplies an alternating current of a predetermined oscillation frequency to the LC circuit. A signal voltage outputted from the LC circuit has a first voltage when the distance between the coil and the conductor is minimum and a second voltage when the distance between the coil and the conductor is maximum. A voltage difference between the first and second voltages has a first difference at a first temperature and has a second difference at a second temperature. The first and second differences become equal to each other at a first frequency and a second frequency. The oscillation frequency is set close to the first frequency or the second frequency.

Abstract: A method for determining a position of a moving object, such as an elevator car in an elevator shaft, includes the steps of mounting a leading sensor and a lagging sensor to the moving object and spacing the leading sensor from the lagging sensor by an offset distance, mounting a plurality of spaced apart position indicators along a pathway of the moving object, transmitting signals representative of object position from the leading sensor and the lagging sensor to a controller as the sensors pass the spaced apart position indicators, and filling any gaps in the signal gathered from one of the sensors by using a correction factor established from the position sensed by the other sensor and the offset distance. A system for performing the method is described.

Abstract: A device for detecting an absolute rotation angle of multiple rotation with a high accuracy and high resolution by using a target connected to the rotation axis and having an outer circumferential surface to which magnetic poles of alternate polarities are magnetized. The device includes: a first rotor holding a target connected to an input axis and having an outer circumferential surface to which magnetic poles of alternate polarities are magnetized at an identical interval and having a multi-rotatable gear; a second rotor connected to the gear of the first rotor, rotated at a low speed by the first rotor, and having a magnet at the center portion; a first detection unit and a second detection unit for detecting the rotation angles of them. With a simple configuration, it is possible to detect an absolution rotation angle with a high accuracy and a high resolution.

Abstract: A sensing system for a vehicle that includes a single sensor element and multiple outputs. An engine controller is responsive to the multiple outputs, output circuits and a supervisor circuit in the system monitors the sensor element and shared circuits. If the sensor element fails, or if a connector fails or if the supervisor circuit indicates a circuit failure, one or more of the outputs will go outside of their normal operating range into a diagnostics range to allow the engine controller to take the appropriate action.

Abstract: A magnetic detection device has stable characteristics having an area of a resist layer covering an insulating passivation layer, forming the magnetic detection element and a connection layer on a small stepped surface with high-precision, and preventing the resist layer from peeling, thereby providing a method of manufacturing the magnetic detection device. A resist layer 42 is overlapped through the insulating passivation layer 41 on an interconnection layer 35.

Abstract: Apparatus and methods for detecting passing magnetic articles using a first, True Power On State (TPOS) detector during a first time interval and transitioning to a second, running mode detector after the first time interval, when the output of the second detector is accurate. A phase comparator is responsive to the output signal of the first and second detectors and provides a control signal indicative of a change in the phase relationship between the two output signals. An output switch controlled by the phase comparator provides, as the detector output signal, the first detector output signal during the first time interval and the second detector output signal thereafter.

Abstract: A method for evaluating a sensor signal provided by a magnetic field sensor which is arranged at a distance from an object which is rotatable about an axis of rotation. The method includes defining an encoding pattern with a sequence of symbols, the sensor signal being dependent on the encoding pattern and at least one transmission parameter; regenerating the symbols of the encoding pattern from a corrected sensor signal using a threshold value detector to obtain an output signal; generating a filtered signal from the output signal using a filter having a plurality of filter coefficients; superposing the sensor signal and the filtered signal to obtain the corrected sensor signal; and wherein the corrected sensor signal and the output signal are used to estimate the at least one transmission parameter, and the filter coefficients are derived from the estimated transmission parameter.

Abstract: A magnetic sensor (MS) for sensing a magnetic stray field (SF) generated by magnetizable object (SPB) when magnetized and for generating an electrical object signal (UOB) which depends on the sensed magnetic stray field (SF), comprising a magnetic field generator (WR1, WR2) for generating a magnetic main field (H) for magnetizing the magnetizable object (SPB), and cross-talk reduction means for reducing the effect of a cross talk signal component in the electrical object signal (UOB) caused by magnetic cross-talk between the magnetic main field (H) and the magnetic stray field (SF), wherein the cross-talk reduction means is arranged for distinguishing a signal property between the cross-talk signal component and the remaining part of the electrical object signal (UOB) and for generating an electrical output signal (Uo).

Abstract: A magnetoresistive sensor element has a first magnetic layer structure, a second magnetic layer structure, and a barrier layer. The resistance R1 of the first magnetic layer structure, the resistance R2 of the second magnetic layer structure and resistance-area product RA define a characteristic length ? of the magnetoresistive sensor element by a functional relation. The contact spacing X0 has an m-fold value of the characteristic length ? with 0.1<m<20, the first contact terminal a first edge spacing X1 from the edge of the first magnetic layer structure with an n-fold value of the characteristic length ? with 0.5<n, the second contact terminal a second edge spacing X2 from the edge of the first magnetic layer structure with a p-fold value of the characteristic length ? with 0.5<p, the resistance R1 a q-fold value of the resistance R2 with q>1.

Abstract: A circuit configuration for processing a signal of a sensor includes an amplifier for amplifying the signal of the sensor. This signal has switch-over points between different signal states. The circuit configuration is constructed in such a manner that the amplifier and the sensor operate continuously in a chopper mode. Furthermore, a control loop is provided for determining offset components in the signal of the sensor and for removing the offset components from the signal of the sensor.

Abstract: A magnetic detector, wherein the magnetic/electric conversion element is constituted by at least six segments symmetrically arranged in a direction in which the magnetic moving body rotates maintaining a predetermined pitch with respect to the center line of the magnet, first and second bridge circuits are constituted so as to produce outputs accompanying the rotation of the magnetic moving body, and a third bridge circuit is constituted so as to produce an output accompanying the rotation of the magnetic moving body, and wherein a comparison level of a comparator circuit that shapes the waveform of a differential output signal of the first and second bridge circuits is adjusted relying upon an output signal of the third bridge circuit.

Abstract: An electromagnetic tracking method includes generating an electromagnetic field (14) in a region of interest (16). The electromagnetic field is subject to distortion in response to a presence of metal artifacts proximate the electromagnetic field. An array of reference sensors (30,50,102,104,110) having a predefined known configuration are disposed proximate the region of interest. A first set of locations of the array of reference sensors is determined with respect to the electromagnetic field generator (12) in response to an excitation of one or more of the reference sensors via the electromagnetic field. A second mechanism (28), other than the electromagnetic field, determines a first portion of a second set of locations of at least one or more sensors of the array of reference sensors with respect to the second mechanism, the second mechanism being in a known spatial relationship with the electromagnetic field generator.

Abstract: Electrical apparatus includes a probe, having a proximal end and a distal end. The probe includes a sensor, which outputs a sensor signal, and a first connector at the proximal end of the probe, electrically coupled at least to the sensor. A probe adapter includes a second connector, which is arranged to mate with the first connector, and a third connector, for coupling to a console.

Abstract: The invention relates to a preferably ferriteless inductive proximity switch having at least one transmitting coil, one oscillator circuit and at least two receiving coils arranged in the alternating magnetic field of the transmitting coil, whereby the transmitting coil and the receiving coil are arranged adjacent to each other on a printed circuit board, and also having an evaluation circuit connected to the receiving coil for evaluating the received signal of the receiving coils when a target approaches the proximity switch.

Abstract: A magnetoresistive sensor system includes a plurality of chip carriers, such that each integrated circuit among the plurality of chip carriers is associated with a respective magnetoresistive sensing components. A plurality of magnetoresistive sensing components can be arranged in a rotary array, wherein each magnetoresistive component among the plurality of magnetoresistive components is associated with a respective integrated circuit among the plurality of chip carriers and wherein the plurality of magnetoresistive sensing components comprises sensing components that are spaced irregular from one another in order to optimize the performance of the rotary array and meet requirements of a particular magnetoresistive sensing application.

Abstract: A position sensor including a rotatable shaft, a first threaded member, a second threaded member, at least one magnet, and at least one magnetic flux detection device. The first threaded member is connected to the rotatable shaft. The second threaded member is threadably engaged with the first threaded member. The at least one magnet is connected to the second threaded member. The at least one magnetic flux detection device is positioned to detect a magnetic field from the at least one magnet.

Abstract: For compensation of a magnetic field in an operating region a number of magnetic field sensors (S1, S2) and an arrangement of compensation coils (Hh) surrounding said operating region is used. The magnetic field is measured by at least two sensors (S1, S2) located at different positions outside the operating region, preferably at opposing positions with respect to a symmetry axis of the operating region, generating respective sensor signals (s1, s2), the sensor signals of said sensors are superposed to a feedback signal (ms, fs), which is converted by a controlling means to a driving signal (d1), and the driving signal is used to steer at least one compensation coil (Hh). To further enhance the compensation, the driving signal is also used to derive an additional input signal (cs) for the superposing step to generate the feedback signal (fs).

Abstract: Apparatus is provided for tracking an object in a body of a patient in the presence of an interfering article. A set of one or more radiators are adapted to generate an energy field at a fundamental frequency in a vicinity of the object. A position sensor, fixed to the object, is adapted to generate a signal responsive to the energy field. A control unit has access to a database of one or more harmonic frequency patterns associated with one or more respective specific types of interfering articles.

Abstract: The invention relates to a device and to a method for contactlessly recording rotation angles of a rotating element, with a plunger core and with a coil at least partially surrounding the plunger core. The plunger core and the coil move relative to one another in an axial direction according to the rotational motion of the rotating element and causes a change in a coil inductivity of the coil. The inventive device and the inventive method are characterized in that compensating means are provided, which at least partially compensate for the influence of a changing temperature upon the coil inductivity.

Abstract: A system and method for optimally placing radio frequency identification (RFID) antennas. The system varies the placement of RFID tag and interrogator antennas with respect to each other and a stationary object or objects. A signal generator sends a known reference signal to the one or more RFID interrogator antennas. The signal is received by the one or more RFID tag antennas and is displayed upon an oscilloscope, spectrum analyzer or other multipurpose signal measuring device. By this method, the system finds the optimal placement of the antennas with respect to each other and the object or objects.

Abstract: A method for detecting EM field distorting includes sampling a sensor assembly positioned within a volume of interest to acquire measurements of EM fields within the volume of interest, and monitoring the measurements to detect EM field distortion within the volume of interest. The sensor assembly includes a set of EM transmitters and a set of EM receivers fixed thereon. A system for detecting EM field distorting includes a sensor assembly for positioning within a volume of interest, wherein the EM sensor assembly comprises a set of EM receivers, and a set of EM transmitters, wherein the EM receivers and the EM transmitters are disposed at fixed locations on the sensor assembly. The system further includes a tracker configured to sample the sensor assembly to acquire measurements of EM fields generated by the EM transmitters, and monitor the measurements to detect EM field distortion within the volume of interest.

Abstract: A position determining system for determining a position of a rotor of a rotating motor has sensors that are coupled to the rotor. The sensors generate, in response to a rotation of the rotor, a quadrature signal that has sine and cosine components. The position determining system calculates a sum (A2) of a squared value of the sine component (A2sin2x) and a squared value of the cosine component (A2cos2x). An amplitude correction factor (A) is calculated as the squared root of the sum (A2). An amplitude corrected sine component (sin(x)) is obtained by dividing the sine component (Asin(x)) by the amplitude correction factor (A). An amplitude corrected cosine component (cos(x)) is obtained by dividing the cosine component (Acos(x)) by the amplitude correction factor (A).

Abstract: A method and system for calculation of rotation dependent parameters in a system that senses shaft rotation of a toothed speed wheel. The method includes determining the passing edges of multiple gear teeth on a rotating speed wheel; calculating rotational speed of the rotating machine based on the passing edges of multiple gear teeth of the speed wheel; calculating a rotation independent tooth spacing correction factor for each gear tooth on the rotating wheel; and correcting the calculated rotational speed of the rotating machine using the tooth corrections.

Abstract: The invention relates to a device and a method for correction of the position (x) of a field sensor (4) measured by means of a magnetic localization device. External field distortions, such as caused for example by the rotating components (1a, 1b) of a computer tomograph (1), are then determined with the help of reference sensor (3) placed at a known position. It is possible to deduce, for example, the current angle of rotation (?) of the computer tomograph (1) from the measurement signals of the reference sensor (3). Based on an empirically determined correction (?(x, ?)), the uncorrected determined positions (x) of the field sensor (4) can then be converted to corrected positions (x?) in relation to the field distortions. The field generator (2) and the reference sensor (3) are preferably fastened to the gantry in order to eliminate the dependency of the field distortions on an inclination of the gantry.

Abstract: A sensor device includes a movable object, a first sensor element with a first magnetically encoded region and a second magnetically encoded region, and a second sensor element with at least a first magnetic field detector. The first sensor element is provided at to the movable object. The first magnetically encoded region is adapted to generate a magnetic reference signal in the first magnetic field detector of the second sensor element.

Abstract: An electromechanical conversion device includes an electromechanical conversion unit and a cable, which has a signal wire and a ground wire for grounding the electromechanical conversion unit. The electromechanical conversion unit performs a conversion between a relative movement with respect to a magnetic field generation unit and electrical signals, based on a magnetic field generated by the magnetic field generation unit. The signal wire is connected with the electromechanical conversion unit to transfer the electrical signals, and has a first branch portion and a second branch portion which extend substantially parallel to the ground wire and are respectively arranged at two opposite sides of the ground wire. A distance between the first branch portion and the ground wire is substantially equal to that between the second branch portion and the ground wire.

Abstract: An interpolation apparatus in an encoder includes an analog-to-digital converter for digitizing a sine wave signal and a cosine wave signal, respectively. An amplitude level detecting circuit detects each amplitude level of the digitized sine wave signal and cosine wave signal. A computing circuit multiplies the amplitude level of one of the signal by an interpolation position parameter according to a tangent value at an interpolation position. A comparing circuit compares an output from the computing circuit to an output from the amplitude level detecting circuit. The comparison is made at every the interpolation position. A region detecting circuit identifies a region sectionalized by the interpolation positions adjacent to each other based on an output from the comparing circuit corresponding to each the interpolation position. The phase angle of the sine wave signal and the cosine wave signal exists in the region.

Abstract: A device and method for detecting the position and velocity of a test object relative to a sensor, the sensor and the test object being arranged such that they can be displaced relative to one another. In one embodiment, the sensor has a measuring coil with one or more voltage tap(s) and has a target that is placed on the test object while being electromagnetically coupled to the measuring coil. An electronic component for adding the voltages tapped on the sensor is assigned to the sensor.

Abstract: A method for tracking an object includes producing energy fields at a plurality of different frequencies in a vicinity of the object, and receiving signals that are generated at a location of the object at the different frequencies in response to the energy fields. Multiple computations are made of spatial coordinates of the object based on the signals received at the different frequencies. Convergence of the computations is tested in order to ascertain whether the energy fields have been perturbed by an article in the vicinity of the object.

Abstract: A device to correct interference errors in a measuring installation (A) that includes at least two magnetic sensors (11, 12) for measuring the position of mobile elements (21, 22) that are moving along adjacent trajectories, with each magnetic measuring sensor delivering a measurement signal that is representative of the position of the mobile element in an open magnetic circuit (31, 32), and resources (M) for processing the measurement signals delivered by the magnetic measuring sensors. According to the invention, the processing resources (M) include resources for correction of the magnetic measurement signals in order to take account of interference errors between adjacent magnetic sensors (11, 12), with a view to obtaining a corrected measurement signal for each magnetic measuring sensor.

Abstract: A sensing device includes a circuit that compensates for time and spatial changes in temperature. The circuit includes elements to correct for variation in permeability of a highly permeable core of a differential variable reluctance transducer as temperature changes. The circuit also provides correction for temperature gradients across coils of the transducer.