Abstract: Disclosed is a bearing including a bearing ring and an inductive angular displacement sensor of the bearing ring, which includes a transducer and a target. The target is formed from a single conductive metal part and including a face with a base wall and one or a plurality of metal studs projecting from this base wall. The target is fastened firmly to the bearing ring, or is machined directly in the bearing ring.

Abstract: A magnetic field sensor includes a circular vertical Hall (CVH) sensing element to produce a signal representing an external magnetic field as detected by the CVH sensing element, a sigma-delta analog-to-digital converter to generate a converted signal, modulators to produce quadrature modulated signals from the converted signal, and a processor to produce an estimated angle of the external magnetic field using the quadrature modulated signals. An arctangent function may be used to calculate the estimated angle. A sliding window integration scheme may be used over one or more CVH cycles.

Abstract: A stator structure includes a stator core including a plurality of tooth sections, coils wound around the respective plurality of tooth sections via an insulator, and a first coil cover and a second coil cover that cover the coils from both sides in an axial direction of the stator core. The first coil cover and the second coil cover being coupled via the insulator.

Abstract: The present invention relates to a system (100, 300, 400) for detecting abnormal movement of a gas turbine shaft. The system comprises: a magnetic circuit (104, 302, 402) comprising a first magnetic portion (110, 304) and a second portion (112, 404), and including at least one air gap between the first portion and the second portion; and a detection coil (106) wound around the first magnetic portion. The second portion is coupled to or moveable with the shaft to reduce the air gap, on axial movement of the shaft to change the reluctance of the magnetic circuit and thereby induce a voltage in the coil. The system may comprise a controller (108) for shutting off power to the gas turbine when the induced voltage exceeds a threshold voltage.

Abstract: An electronic device is provided. The electronic device includes a housing including at least one receiving hole exposed to an outside, a magnet disposed inside the housing and adjacent to the at least one receiving hole, an input module configured to be insertable into the at least one receiving hole and including a ferrite core configured to block or redirect part of a magnetic field generated from the magnet, a sensor unit disposed inside the housing and configured to sense the magnetic field generated from the magnet, and a controller configured to sense whether the input module is inserted into the at least one receiving hole by a signal according to a strength of the magnetic field sensed by the sensor unit.

Abstract: An angle sensor includes detection units and an angle computation unit. The detection units detect a composite magnetic field of a magnetic field to be detected and a noise magnetic field. Each detection unit generates a first detection signal representing the strength of a component in a first direction of the composite magnetic field, and a second detection signal representing the strength of a component in a second direction of the composite magnetic field. The angle computation unit generates a detected angle value by performing computations using a plurality of pairs of first and second detection signals generated at the detection units wherein an error of the detected angle value resulting from the noise magnetic field is made smaller than in the case of generating the detected angle value on the basis of only a pair of first and second detection signals generated at any one of the detection units.

Abstract: A system comprising: at least one platform configured for, in use, having a person on it, said platform comprising a plurality of sensors configured for capturing information of forces/pressures applied by the feet of the person or of the position of the person's feet; means for, from said captured information, respectively extracting either a center of pressure or the position of the feet; at least one reference signal disposed at a known location with respect to said platform; at least one sensor which, in use, is connected to the body of the person situated on said platform, the sensor being configured for capturing said at least one reference signal; processing means for extracting information from said at least one captured reference signal and for estimating the position and/or orientation of said at least one sensor; processing means for estimating the position and/or orientation of the body of said person; processing means for calculating a stability index from said position and/or orientation of the

Abstract: In one embodiment, a sensor arrangement for the contactless sensing of angles of rotation on a rotating part includes a disk-shaped target, a coil arrangement, and an evaluation and control unit. The disc-shaped target is coupled to the rotating part and includes at least two metal surfaces that influence the inductances in the flat detection coils due to eddy current effects as a function of the degree of overlap. The disc-shaped target can generate at least one piece of information for ascertaining the instantaneous angle of rotation of the rotating part, in connection with the coil arrangement. The coil arrangement has three flat detection coils uniformly distributed on the circumference of a circle. The evaluation and control unit can generate essentially sinusoidal evaluation signals which represent the changes in inductance of the detection coils and can evaluate them for calculating the angle of rotation.

Abstract: An inductive sensor includes a sensor package and a coupler package. The sensor package includes a signal processor, an integrated capacitor, a ferrite layer, a transmitter coil, a two part receiving coil, and a plurality of discrete components. The coupler package includes an integrated capacitor, a ferrite layer, and a coupler coil. The transmitter coil in the sensor package is energized by an external power source which in turn energizes the coupler coil in the coupler package. The sensor then measures the rotational position of the coupler package relative to the sensor package by detecting and measuring, with the two part receiving coil, the signal returned by the coupler coil. The signal processor calculates the position of the coupler package relative to the sensor package by comparing the coupling factors between the coupler package and the sensor package.

Abstract: An inductive position detector with a first and second body, at least one of said bodies being displaceable relative to the other along a measurement path wherein said first body comprises one or more antenna windings forming a first arrangement of windings and said second body comprises a passive resonant circuit incorporating one or more target windings in series with a capacitor; said circuit covering at least in part said first arrangement; characterized in that said first body comprises an additional winding arrangement disposed along at least part of said measurement path; said additional winding arrangement being spaced from said first arrangement of windings; and said second body comprises an additional winding arrangement covering at least in part said additional winding arrangement of said first body.

Abstract: Various embodiments include apparatus and methods to utilize signals acquired from a multi-component induction tool operating in a wellbore. The acquired signals can be correlated to an apparent conductivity of a formation and mapped to components of the apparent conductivity tensor conductivity. A multi-stage inversion scheme can be implemented to determine three-dimensional formation parameters from operating the multi-component induction tool. Additional apparatus, systems, and methods are disclosed.

Abstract: A method for determining the position ? of a moving part (T) along an axis (X), using an inductive sensor (10) including: a primary winding (B1) generating an electromagnetic field; a first secondary winding (R1), generating a first voltage signal (V1), of the sine function type; a second secondary winding (R2), generating a second voltage signal (V2) of the cosine function type; and a calculation unit (20?), wherein the method includes the steps of calculating and distributing linearization points i on the arctangent function tan(?) resulting from the ratio of the first voltage signal to the second voltage signal, the linearization points i being distributed according to a sinusoidal function in order to reduce the error on the position (?) of the target (T) at the ends (E1, E2) of the primary and secondary windings (R1, R2).

Abstract: A transmitter which emits at least two electromagnetic fields. An amplitude of each of the at least two electromagnetic fields has an anisotropy in one plane. An angular arrangement of the receiver relative to the transmitter is determined based on the amplitude of the at least two electromagnetic fields at the position of a receiver.

Abstract: A method of accounting for the movement of the lungs during an endoscopic procedure such that a previously acquired image may be dynamically registered with a display showing the position of a locatable guide. After an initial image set is acquired, an area of interest is identified and the movement thereof due to breathing is mathematically modeled. Patient movement sensors are then used to provide information on the patient's breathing patterns. This information is entered into the mathematical model in order to update the registration between the image set and a display showing the position of the locatable guide.

Abstract: According to embodiments, multi-axis magnetic sensors (magnetometers) are disposed in an array or a plurality of arrays. The magnetic sensors can be disposed on modules that form the array. The magnetic sensors can each sense a local magnetic field coincident with the respective sensors. Data corresponding to the local magnetic fields can be analyzed by a magnetic field analysis circuit and assembled to form an image corresponding to the sensed magnetic field(s). The magnetic field analysis circuit can output the image corresponding to near-field magnetic features.

Abstract: A sensor including a set of coils. The set of coils include a first coil and a second coil, wherein the first coil upon receiving energy, generates an electromagnetic near-field, such that the electromagnetic near-field provides at least a portion of the energy to the second coil through inductive coupling, inducing a current to pass through the set of coils. Further, a detector for measuring a voltage across at least one of the first coil or the second coil, wherein the detector includes a voltmeter. Finally, a processor for detecting a presence of a target structure in proximity to the set of coils upon detecting a change in a value of the voltage, wherein the target structure is an electromagnetic structure moving at a distance from the set of coils.

Abstract: Remote sensors and methods of remote sensing are disclosed. A remote sensor includes a first circuit and a second circuit. The first circuit includes a first coil, a magnetic field generator for driving a current through the first coil to generate a magnetic field, and circuitry for determining loading of the magnetic field. The second circuit includes a second coil located proximate the first coil and a voltage-to-current converter for converting a voltage at an input of the second circuit to current and applying the current to the second coil. The current in the second coil registers as a loading of the magnetic field generated by the first coil. The loss, in response to the loading of the magnetic field, is measurable by the first circuit.

Abstract: An angle sensor is provided for determining an absolute angle signal of a first part rotated with respect to a second part. The angle sensor comprises a first grating ring for generating a first signal representative of a relative position of a first sensor along a corresponding ring segment of the first grating ring. The angle sensor further comprises a second grating ring for generating a second signal representative of a relative position of a second sensor along the corresponding ring segment of the second grating ring. The first plurality and the second plurality are co-prime numbers and a difference between the first plurality and the second plurality being larger than 1. The angle sensor also comprises a calculator configured for calculating the absolute angle signal using a first linear combination of the first signal and the second signal.

Abstract: Disclosed herein are a signal transmission/reception method for signal analysis in FMMD technology and an apparatus using the method. A signal transmission apparatus includes a signal generation unit for generating two sine wave signals having different frequencies in consideration of a voltage of an excitation coil included in a magnetic particle measurement sensor, a signal addition unit for generating an input signal for producing a magnetic field by electronically adding the two sine wave signals, a differential signal generation unit for generating a differential signal for the input signal to minimize transmission noise, and a signal transmission unit for amplifying voltages of the input signal and the differential signal and transmitting the amplified input signal and differential signal to the excitation coil so as to produce a magnetic field in the excitation coil and apply the magnetic field to a measurement target sample.

Abstract: The subject invention reveals a distance measuring device comprising: a sensing module, a target module, and an evaluating module, wherein the sensing module and the target module are mountable so as to execute a movement with respect to each other along a movement trajectory, wherein the target module comprises a magnetic field generating element having a magnetic pole axis, wherein the sensing module comprises a first magnetic field sensing array being arranged distant to the movement trajectory. The sensing module and the target module can advantageously be situated within the pressurizable chamber of an air spring which is defined by (contained within) a first mounting plate, a second mounting plate, and a flexible member of the air spring.

Abstract: A parking meter receives data indicative of a remote payment being completed and displays an amount of time purchased by the remote payment for a parking session. The parking meter determines an amount of time remaining in the parking session and powers down at least a portion of a meter communication subsystem subsequent to receiving the data indicative of the remote payment being completed. The parking meter wakes up the powered down portion of the communication subsystem upon determining that the amount of time remaining is below a threshold time, and can receive an indication of additional time being paid for remotely, and can update the displayed time remaining to reflect the additional time.

Abstract: Disclosed is a voltage sensing apparatus comprising a signal generator coupled to a first conducting layer and a conductive element having a first voltage, the signal generator configured to superimpose a second voltage to the first voltage. The voltage sensing apparatus also comprises a meter disposed between the first conducting layer and a second conducting layer or between the signal generator and the second conducting layer. An output parameter of the meter is a function of one or more of the group consisting of: the first voltage and the second voltage. The output parameter and the second voltage can be used to adjust a determination of the first voltage.

Abstract: A method for detecting induction coil alignment error in resonant induction wireless power apparatus includes an eddy current coil array superimposed upon the primary induction coil, a switching device for each eddy current coil, a voltage detector such as a low power rectifier connected to the secondary induction coil, an analog-to-digital converter, primary and secondary side micro-controllers, and, in a vehicle charging embodiment, a vehicle operator interface. During coil alignment, the primary side induction coil operates at low power. Eddy current flows in an eddy current coil only if the associated switching device is switched on.

Abstract: A garage door opener system includes sensor components and actuatable components. When a condition is detected based on sensor output, a responsive action is selected. The actuatable component is controlled to perform the selected responsive action. Accessory sensors and actuatable accessories may be in communication with the garage door system. When the accessories are found to be present by the garage door opener system, and a condition is detected by the accessory sensor, a responsive action is selected and the actuatable accessory is controlled to perform the responsive action. In either case, the responsive actions may be selected based on rules. The responsive actions may be performed by a combination of the actuatable components of the garage door opener system and the actuatable accessories in communication with the garage door opener system.

Abstract: The invention relates to an electromagnetic position tracking system, including: an electromagnetic field emission device including at least one emitter coil and, connected to the emitter coil, a first generator of an electric signal for exciting the emitter coil; a device for receiving the electromagnetic field emitted by the emission device, including at least one receiver coil, and, connected to the receiver coil, a circuit for reading an electric signal induced in the receiver coil; and a system for measuring at least one parameter of the reception device, including, connected to the receiver coil, a second generator of an electric signal for exciting the receiver coil.

Abstract: The present disclosure provides device and method for measuring cervical vertebra movement. The device comprises a sensor unit, a computation unit, a storage unit and a determination unit. The sensor unit comprises at least one transmission part and at least one reception part. Either of the transmission part and the reception part moves along with user's head, the other fixes relative to user's body. The transmission part transmits detection signals and the reception part receives them. The computation unit computes, based on detection signals, distance changes in a distance between the transmitting and reception part before and after user's head moves. The storage unit stores a mapping table indicating relations between distance changes and movement angles of user's head. The determination unit inquires the mapping table based on distance changes to determine movement angles of user's head. The device is simple, easily operated and practicable.

Abstract: An athermal open-loop hung mass accelerometer configures the CTE of the sensor heads such that any growth by the body in response to a body temperature gradient along the longitudinal axis is offset by the growth of the sensor heads in the equal and opposite direction to null the effects of the temperature gradient. In many configurations, the sensor head CTE is strictly less than the body CTE and typically between 60-80% of the body CTE to null the effects of the predicted body temperature gradient.

Abstract: The invention proposes an inductive measuring probe and a method for operating the measuring probe. The measuring probe is equipped with a movably arranged probe element, with a sensor (1) having a coil arrangement (14) and a core (15) which is arranged such that it can be displaced in relation to the coil arrangement (14) and which is connected to the probe element, wherein the sensor (1) converts a deflection of the probe element into an analog measurement signal, with an electrical reference component (2) which converts an analog input voltage into an analog output voltage, with a drive device which generates an identical analog input voltage for the sensor (1) and the reference component (2), with a processing device which determines the influence of disturbing effects from the analog output voltage of the reference component (2), and which determines a measurement result from the measurement signal and the influence of disturbing effects.

Abstract: A device (1) for contactless charging of an electrical energy storage (2) of a motor vehicle that has a height adjustable chassis. A primary coil (3) is arranged in a bottom housing (4) on a surface on which the motor vehicle will be parked. The primary coil (3) is connected to an electrical power supply and will induce an alternating electrical voltage in a secondary coil (6) on the vehicle for charging the electrical energy storage (2). The primary coil (3) is connected to the bottom housing (4) by a spring (8, 9) that will compress under the effect of an external compressive force that may occur if the chassis is adjusted too low, thereby avoiding damage to either of the coils (3, 6).

Abstract: A stator device for a linear motor comprises an electrically energizable magnetic field generator for forming a magnetic field, and a first holding device for holding the magnetic field generator, wherein the magnetic field generator is fastened to the first holding device, wherein the first holding device is formed at least partially from an any of an electrically and magnetically non-conductive material, wherein the magnetic field generator comprises a coil and a stator tooth as a core around which the coil is wound, and wherein the first holding device is in the form of a printed circuit board for electrical contacting of the magnetic field generator.

Abstract: A first oscillation circuit in which a helical antenna is used as a part of an element for a resonance circuit and a second oscillation circuit in which a loop antenna is used as a part of an element for a resonance circuit are caused to oscillate at substantially the same frequency. When a human body approaches the helical antenna and the loop antenna, the frequency difference between the first oscillation circuit and the second oscillation circuit increases. This frequency difference is extracted using a BPF.

Abstract: The present disclosure generally relates to a signal transmission path evaluation device and method for evaluating EMC resistance of a signal transmission path using a computer system. An operating device of the computer system is input with signal transmission line shape data, signal transmission line path data, signal transmission line shape dispersion data, and margin information for noise input of a communication device connected to the signal transmission line. Calculations are performed including an electric field or a magnetic field in a vicinity of the signal transmission line path from the signal transmission line path data, dispersion of the signal line transmission line shape via a random number, noise waveform at a communication device input from the electric field or the magnetic field in the vicinity of the signal transmission path, error occurrence determination, and error rate from plural time trial results. Information concerning the calculated error rate is output.

Abstract: A sensor arrangement for detecting a pedal movement in a vehicle includes a measurement value transmitter that is arranged on a piston that is translated by the pedal movement and a measurement value sensor that is arranged in a stationary manner in the movement region of the piston. The measurement value sensor in connection with the measurement value transmitter generates a signal that represents the pedal movement. The measurement value transmitter and the measurement value sensor are configured as inductive sensors. The measurement value transmitter has at least one detection region, and the measurement value sensor has at least one detection coil. The at least one detection region of the measurement value transmitter influences the inductance of the at least one detection coil such that the changing inductance of the at least one detection coil of the measurement value sensor is interpreted as a measure of the pedal movement.

Abstract: A valve comprises a tappet and a sensor for detecting an adjustment stroke of the tappet, in particular an inductive sensor, wherein the sensor comprises a signal transmitter which comprises a coil, of which the coil axis (S) is substantially in parallel with the axis (A) of the tappet.

Abstract: A processor of a position detection device intermittently performs an acquisition process during a measurement period to acquire a detection signal induced in a detection coil depending on the position of an object by driving an excitation coil. The processor configured to monitor whether or not the processor is executing the acquisition process without driving the excitation coil during a monitoring period set before the measurement period of the processor, and the processor is configured to execute a predetermined process when the processor is executing the acquisition process.

Abstract: Apparatus for determining a location of a target, the apparatus comprising: first and second magnetic dipole beacons positioned at substantially a same spatial location having respectively first and second time dependent magnetic moments oriented in different directions that generate first and second magnetic fields having different time dependencies; at least one magnetic field sensor coil located at the location of the target that generates signals responsive to the first and second magnetic fields; and circuitry that receives the signals generated by the at least one sensor coil and processes the signals responsive to the different time dependencies of the magnetic fields to determine a location of the at least one sensor coil and thereby the target.

Abstract: Embodiments relate to a position sensor comprising a magnetic target. The magnetic target includes a magnetic multipole configured to generate a magnetic field. The magnetic field has three mutually-perpendicular components at a first region. Sensor elements can be configured to measure these field components at the first region. In embodiments, comparing the amplitudes of the components can be used to determine a global position, and the instantaneous values of these components can be used to determine a local position.

Abstract: Detection of corrosion and other defects in piping is needed to prevent catastrophic pipeline failure. Sensors, systems and methods are provided to enable detection of such defects. These apparatus and methods are configured to characterize pipe protected by insulation and conductive weather protection. The sensors may utilize inductive and/or solid state sensing element arrays operated in a magnetic field generated in part by a drive winding of the sensor. Multiple excitation frequencies are used to generate the magnetic field and record corresponding sensing element responses. Relatively high excitation frequencies may be used to estimate the properties of the weather protection and sensor lift-off while lower frequencies may be used to detect internal and external pipe damage. Linear arrays may be moved to generate damage images of the pipe providing size and location information for defects. Two dimensional sensor arrays may be used to provide imaging without moving the sensor.

Abstract: The invention relates to a sensor arrangement having an angle sensor for the measurement of rotations. The angle sensor is multipolar such that measurements are possible by means of n poles. First of all the angle sensor comprises a sensor ring surrounding an axis of rotation (04) and a material measure which is rotatable relative to said sensor ring. A transmitting coil (27) and a plurality of receiving coils (28) are disposed on the sensor ring. Between the transmitting coil (27) and the receiving coils (28) a magnetic circuit is formed which comprises the material measure and a pot core (17) having two branches (19). To this end the material measure forms a variable reluctance in the magnetic circuit. One of the two branches (19) of the pot core (17) is segment-like, such that said branch comprises ring segments (38). In each case the receiving coils (28) surround one of the ring segments (38). The ring segments (38) each form an arc of a circle having a mean radius (43, 46, 48, 51).

Abstract: An afterloading device for effectuating a brachytherapy treatment, comprising a first elongated flexible transport element, arranged to maneuver a radiation source between a storage position inside the afterloading device and a treatment position outside the afterloading device, the afterloading device further comprising a second elongated flexible transport element, having at least one transducer, the second transport element being arranged to move the at least one transducer between a first transducer position and a second transducer position.

Abstract: One example includes a position sensing system. The system includes an inductive position element that is moveable and comprises a position inductor. The system also includes a plurality of inductive load elements. Each of the inductive load elements includes a load inductor. Each of the plurality of inductive load elements can be selectively controlled in response to a modulation signal to provide a corresponding mutual inductance between the position inductor and the respective load inductor, the corresponding mutual inductance depending on a position of the inductive position element relative to the respective load inductor. The system further includes a position controller configured to generate the position and modulation signals and to calculate the position of the inductive position element relative to the plurality of inductive load elements based on a difference of the position signal with respect to the mutual inductance between the position inductor and each respective load inductor.

Abstract: A position sensor includes a first transmission coil, a second transmission coil having a different shape from the first transmission coil, a receiver coil for receiving electromagnetic waves transmitted from the first and second transmission coils, a transmission waveform generator that inputs first and second input waves to the first and second transmission coils having frequencies identical to each other and having phases different from each other, and a position detector that detects a position of a target provided movably with respect to the first transmission coil, the second transmission coil, and the receiver coil based on a first output signal obtained from the receiver coil in response to the first and second input waves input from the transmission waveform generator to the first and second transmission coils, respectively.

Abstract: Embodiments relate to a position sensor comprising a magnetic target. The magnetic target includes a magnetic multipole configured to generate a magnetic field. The magnetic field has three mutually-perpendicular components at a first region. Sensor elements can be configured to measure these field components at the first region. In embodiments, comparing the amplitudes of the components can be used to determine a global position, and the instantaneous values of these components can be used to determine a local position.

Abstract: A method of identifying a direction of a multilayer ceramic capacitor includes the steps of transporting a plurality of multilayer ceramic capacitors in one line before each of a magnetism generator and a magnetic flux density measurement instrument, measuring a magnetic flux density with the magnetic flux density measurement instrument at the time when each of the plurality of multilayer ceramic capacitors passes before the magnetic flux density measurement instrument, and identifying a direction of stack of the multilayer ceramic capacitors based on the magnetic flux density measured in the step of measuring a magnetic flux density.

Abstract: Systems and related methods for measuring pelvic organ prolapse are disclosed. A plurality of positioning devices, such as RFID tags, ultrasound reflectors or magnetic field sensors, which may be active or passive, and which are preferably disposable, are set at predetermined positions within the patient and their relative positions recorded with one or more corresponding external receiving devices fixed to the patient while the patient is in a relaxed state. The patient is then instructed to perform an action (such as a valsalva maneuver) that causes the positioning devices to move and their movement relative to their initial recorded positions is measured.

Abstract: A current sensor comprises a first component comprising plural coils. Each coil comprises one or more turns printed on at least one planar surface of a respective substrate, and the planes of the coils are parallel to one another and are perpendicular to a longitudinal axis of the first component. A second component comprises soft magnetic material and has first and second planar faces that are at opposite ends of the first component and are arranged perpendicularly to and are intersected by the longitudinal axis of the first component.

Abstract: Inductive displacement sensors and methods of using them may be useful in a variety of contexts. For example, systems for precisely measuring linear or angular motion may use inductive displacement sensors to measure changes in position. An apparatus, such as a sensor, can include a primary inductor. The apparatus can also include a first secondary inductor that is field-coupled to the primary inductor. The apparatus can further include a second secondary inductor that is field-coupled to the primary inductor. The first secondary inductor and the second secondary inductor can be configured as coordinated inductors to detect motion of a coupler. The coordinated inductors can be configured to provide a reference signal and a measurement signal, wherein the reference signal has a constant amplitude across a range of motion of the coupler.

Abstract: Provided is a differential transformer magnetic permeability sensor that accurately suppress a variation of output level of each sensor even if a position shift occurs in forming a detection coil, a reference coil, and a drive coil as planar coils. The differential transformer magnetic permeability sensor includes a first coil layer including a first drive coil constituted of a first wire of a flat winding and a detection coil constituted of a second wire of a flat winding, a second coil layer including a second drive coil constituted of a third wire of a flat winding and a reference coil constituted of a fourth wire of a flat winding. The first drive coil and the second drive coil are connected so that drive current have the same direction, while the detection coil and the reference coil are connected so that induced current have opposite directions.

Abstract: A sensor device for determining the position of a metal body comprising at least one Eddy current sensor, which has a coil for generating a high-frequency electromagnetic alternating field and a device for operating the coil and for detecting an impedance of the coil, and comprising an analyzing device, which determines the position of the metal body relative to the coil using the detected impedance. A reference Eddy current sensor is provided which has a reference coil for generating a high-frequency electromagnetic alternating field and a reference device for operating the reference coil and for detecting an impedance of the reference coil and which is oriented/designed such that the electromagnetic alternating field of the reference Eddy current sensor is free of metal bodies, wherein the analyzing device is designed to form a beat from the detected impedance and to determine the position of the metal body dependent on the beat.

Abstract: An absolute scale configuration is provided for use in a position encoder which includes a readhead and a scale. The absolute scale configuration includes a plurality of scale loops distributed along a measuring axis to provide a position dependent signal that varies depending on a relative position between the scale loops and the readhead. At least some of the scale loops are coupled to respective impedance modulating circuits connected to receive energy from current induced in the scale loop and to provide a unique coded modulation of the scale loop impedance during a code signal generating state. The unique coded modulations as sensed by the readhead are indicative of a coarse resolution absolute position, which may be utilized in combination with the position dependent signal to determine an absolute position with a high resolution.