Abstract: Systems, methods, and other embodiments associated with automated calibration in electromagnetic scanners are described. In one embodiment, a method includes: detecting one or more peak frequency bands in electromagnetic signals collected by the electromagnetic scanner at a geographic location; comparing the one or more peak frequency bands to broadcast frequencies assigned to local radio stations of the geographic location; and indicating that the electromagnetic scanner is calibrated by finding at least one match between one peak frequency band of the peak frequency bands and one of the broadcast frequencies. An electromagnetic scanner may be recalibrated based on comparing the one or more peak frequency bands to broadcast frequencies.

Abstract: A blade angle feedback assembly for a variable-pitch rotor of an aircraft engine, the rotor rotatable about an axis and having rotor blades rotatable about respective spanwise axes to adjust a blade angle thereof, is provided. A sensor is configured to provide feedback on the blade angle of the rotor blades by detecting a relative movement between the sensor and a feedback device having at least one position marker thereon. The sensor comprises a magnet having a magnetic field and a first pole and a second pole opposite the first pole. A magnetic shield is configured to define a magnetic return path for at least a portion of a magnetic flux of the magnetic field exiting from the first pole of the magnet toward the second pole, the magnetic shield comprising at least one wall member spanning a distance of relative displacement between the feedback device and the sensor.

Abstract: The present disclosure relates to an electrostatic shield for providing electrostatic shielding for a current sensing coil. Current sensing coils are configured to enable the measurement of a current carried by an electrical conductor passing through a core of the current sensing coil. The electrostatic shield of the present disclosure is configured to provide electrostatic shielding to a core of the current sensing coil in order to reduce or eliminate electrostatic coupling between the electrical conductor and the current sensing coil, thereby improving the accuracy of current measurement that may be achieved by the current sensing coil.

Abstract: Systems, methods, and other embodiments associated with automated calibration of electromagnetic interference (EMI) fingerprint scanning instrumentation based on radio frequencies are described. In one embodiment, a method for detecting a calibration state of an EMI fingerprint scanning device includes: collecting electromagnetic signals with the EMI fingerprint scanning device for a test period of time at a geographic location; identifying one or more peak frequency bands in the collected electromagnetic signals; comparing the one or more peak frequency bands to assigned radio station frequencies at the geographic location to determine if a match is found; and generating a calibration state signal based at least in part on the comparing to indicate whether the EMI fingerprint scanning device is calibrated or not calibrated.

Abstract: A method for assessing a state of fouling of a reverse osmosis system is provided. The method includes deriving a plurality of impedance values from a low frequency region of an electrical impedance spectrum of a reverse osmosis membrane comprised in the reverse osmosis system, and determining a state of fouling of the reverse osmosis system based on the plurality of derived impedance values. Use of the method for in-situ monitoring of fouling on a reverse osmosis membrane, and an apparatus for assessing a state of fouling of a reverse osmosis system are also provided.

Abstract: A device for inductive positioning comprises a coil, an element for influencing a magnetic field in the area of the coil, a signal generator for providing a digital signal and a delay element with an input and an output, wherein the delay element is designed on the basis of the coil and a delay period between a signal edge at the input and a corresponding signal edge at the output is dependent on the inductance of the coil. The device further comprises a comparator to provide a digital differential impulse, whose length is dependent on a time difference of corresponding signal edges at the input and the output of the delay element, an integrator to provide a voltage depending on the length of the differential impulse and an evaluator to determine the position of the coil in reference to the coil based the voltage.

Abstract: A position detection sensor includes a plurality of position detection loop coils formed on a board made of resin through a thermal process by forming a wiring path pattern made of copper paste that includes copper powder and a binder. Each of the position detection loop coils includes a plurality of first portions that extend on a first surface of the board in a first direction and a plurality of second portions that extend on a second surface of the board in a second direction that is orthogonal to the first direction. The wiring path pattern is disposed on the first surface and the second surface in a connector section that connects the position detection loop coils to external circuitry. The position detection sensor is capable of maintaining accuracy even though the loop coils are formed on the board by the thermal treatment using copper paste.

Abstract: The present disclosure relates to a measuring device for measuring a fill level of a material in a container based on time of flight principles, including components that serve to generate, transmit and receive a measurement signal and further serve to convert said measurement signal into an analog intermediate frequency signal having an expected signal frequency within a predetermined frequency range, said intermediate frequency signal including information corresponding to the fill level of the material in the container, wherein an analog to digital converter is provided that serves to subsequently sample the intermediate frequency signal, said analog to digital converter employing a sampling frequency less than the expected signal frequency of intermediate frequency signal.

Abstract: Various embodiments of the present disclosure provide a ride height sensing system that includes an encoded electromagnetic source as an input unit for a Hall Effect sensors and the signal from the electromagnet is encoded to enable the rejection of ambient magnetic field. In various embodiments, the ride height sensing system includes a self-calibration system including at least one Hall effect sensor mounted at a fixed distance and orientation with respect to the electromagnetic source to provide for continuous calibration of the system. In one embodiment, the enhanced ride height sensing system includes at least two inertial measurement units, such as accelerometers mounted to each of the body frame of the vehicle and the axle frame of the vehicle. This enables the system to optimize power usage by more accurately and efficiently measuring the ride height at high frequency rates with relatively lower power consumption.

Abstract: A system for detecting valve seating in a valve system such as a fuel admission valve system includes seat detection circuitry coupled with a low-side driver circuit in solenoid actuator circuitry for the valve system. The seat detection circuitry includes a voltage probe for sensing voltage in the solenoid actuator circuitry, delay circuitry, and a comparator coupled with the delay circuitry and the voltage probe and having an output dependent upon change in the sensed voltage over time. A timing of voltage changes is observed to enable valve seating detection.

Abstract: Methods and apparatus are disclosed for positioning a vehicle. An apparatus for determining positioning information for a vehicle may comprise a plurality of receive coil circuits and a hardware processor. The plurality of receive coil circuits is configured to generate voltage signals from a magnetic field. The hardware processor is configured to generate position estimates of a position of the magnetic field generator with respect to a position of the plurality of receive coils. Each of the first sequence of position estimates is determined based upon a corresponding voltage vector derived from the voltage signals and at least one of a plurality of reference vectors. The hardware processor is configured to update the plurality of reference vectors based upon the first sequence of position estimates and a second sequence of position estimates generated based upon a source different from the plurality of receive coil circuits.

Abstract: In an embodiment of the present invention, there provides an input device, a touch screen, and a user device, in order to increase the sensitivity of signal detection. The present invention relates to the field of signal detection. The input device comprises: a detection unit, a controller, and at least two sensors, wherein the detection unit corresponds to the at least two sensors, the at least two sensors are connected to the controller, and the at least two sensors correspond to at least two input types of the input device. The detection unit is configured to detect an input signal. The sensors are configured to determine the corresponding input type of the input signal after receiving the input signal detected by the detection unit. The controller is configured to control connections and disconnections between the at least two sensors and the detection unit. The embodiment of the present invention is used for signal detection.

Abstract: A method for determining a closing time of a valve having a coil drive may include switching off a current flow through a coil of the coil drive so that the coil is depowered, measuring a time curve of a voltage induced in the non-powered coil, wherein the induced voltage is generated at least partially by a motion of the armature relative to the coil, evaluating the measured time curve of the voltage induced in the coil, wherein the evaluation comprises comparing the measured time curve of the voltage induced in the depowered coil to a reference voltage curve stored in an engine controller, and determining the closing time based on the evaluated time curve. The reference voltage curve is thereby adapted to current operating conditions of the valve. A corresponding device and computer program for determining the closing time of a valve comprising a coil drive are also disclosed.

Abstract: A linear accelerator is disclosed, having a series of interconnected cavities through at least some of which an rf signal and an electron beam are sent, comprising at least one variable coupler projecting into the a cavity of the series, a control apparatus adapted to interpret an electrical signal from the coupler and derive diagnostic information as to the electron beam therefrom, wherein the control apparatus is further adapted to vary the interaction of the at least one coupler with the rf signal in dependence on the diagnostic information. Thus, the accelerator properties can be adjusted by encouraging or inciting an Higher-Order Mode (“HOM”) having a desired effect such as bunching and/or deflecting. The coupler could be rotateable, and partially or fully retractable, to allow its influence to be adjusted and/or for it to be removed from service when not needed.

Abstract: A method of activating an electromagnetic actuator having at least one coil and a movable armature. The method includes the step in which the electromagnetic actuator is demagnetized by passing a sequence of electric current pulses with a current flow direction which alternates from one current pulse to the next and with a current size which decreases from one current pulse to the next, through the at least one coil, in order to reduce or eliminate any residual magnetic flux density in the electromagnetic actuator. The method also includes a step in which a position of the movable armature is determined, after the demagnetization step, by passing a measurement current pulse through the at least one coil.

Abstract: Examples of the present invention include apparatus and methods for monitoring aging of an item. A solid-state structure is located within, adjacent to, or otherwise proximate the item, the solid-state structure including nanostructures. The electrical resistance and/or magnetization of the solid-state structure is determined to determine the degree of aging of the item. In representative examples, the solid-state structure includes nanostructures of a metal, such as a ferromagnetic metal, within a non-magnetic matrix, such as a semimetal, semiconductor, or insulator.

Abstract: An inductive sensor and to a method for manufacturing an inductive sensor is provided. The inductive sensor comprises a winding body, an induction coil made of a high-temperature resistant metal alloy and wound onto the winding body, and a metal casing at least partially surrounding the induction coil. Here, the induction coil is compressed with metal oxide powder inside the metal casing.

Abstract: The invention relates to a measuring device for detecting absolution positions, comprising a sensor unit (N, M) as a planar coil structure and a scale having alternating areas of variable reluctance or conductivity along the measuring line. The invention is characterized in that the measuring device has at least two divisions (T1, T2) for determining the absolute position within the measuring length, the at least two divisions being coded aperiodically and in a bitwise manner and extending parallel to each other and, for each bit formation, having opposite effects on a coil element (S2, S3, S4) as part of the entire sensor structure. Preferably, each coil element (S2, S3, S4), comprising its own emitter and receiver windings (E, R), is balanced in offset, and the entire sensor structure provides approximately equal signal amplitudes for each individual bit of the absolute value at any position of the coded scale by means of compensation windings.

Abstract: A vessel (1) includes a spud (10), a spud lifting device (20) and a plurality of spud guiders (30). The spud guiders (30) are arranged to hold the spud (10) in a substantial vertical orientation and guide the spud (10) when moving in a substantial vertical direction between a lower position in which it can engage with a water bottom and an upper position. The spud lifting device (20) is arranged to lift the spud (10) from the lower position to the upper position. The vessel (1) further includes a spud position detector (40) to detect passage of the lower end (11) of the spud (10) along one or more spud detection points at predetermined heights.

Abstract: A low power inductive proximity sensing system in which a DC voltage to the inductors is only applied for a short time period needed to detect the presence or absence of an appropriate object. After the detection time period is over, DC voltage is no longer applied to the inductors.

Abstract: Provided is an autonomous travel system having an operation management unit including a map database with a combination of topological region maps, on which the range of travel of a vehicle is expressed as points and lines, and metric region maps, on which the travel range is expressed on planar maps; a vehicle position management unit for managing the position of the vehicle; and a vehicle travel planning unit for planning vehicle travel, which, if the vehicle is present near the boundary of a map, blocks the map boundary so that other vehicles will not advance into another map. The operation management unit is provided with a blockage setting unit for dividing a boundary section of a map into a plurality of regions and releasing the blockage of the boundary of a divided region in which no vehicles are present in front of the vehicle in the direction of travel.

Abstract: Inductive sensor module comprising a coil arrangement and a carrier, on which electronic components are arranged, wherein the coil arrangement is arranged on a first side of the carrier and the electronic components are arranged on a second side of the carrier directed away from the first side.

Abstract: A wireless damage detector for ceramic armor plates includes an interrogator and a body armor ceramic plate. The interrogator includes an inductive primary coil having a resonant frequency. The plate includes a corresponding inductive secondary coil adapted to cooperate with the primary coil when the interrogator is positioned in an interrogation position wirelessly adjacent the plate. When in the interrogation position, the primary and secondary coils are inductively coupled, that is, form an inductive coupling, when the primary coil is energized at the resonant frequency. The plate includes at least one self-contained frangible continuity circuit electrically connected to the secondary coil. The inductive coupling induces an electrical current flow in the continuity circuit when the circuit is undamaged. A detector cooperates with the primary and secondary coils when the interrogator is in the interrogation position. The detector detects the inductive coupling. An indicator cooperates with the detector.

Abstract: A measuring arrangement for determining electrical conductivity of a measured liquid, comprising: a container, in which the measured liquid is accommodated, a gradiometer arrangement, comprising an exciter coil, a first receiving coil and a second receiving coil, wherein the first and the second receiving coils are arranged symmetrically relative to the exciter coil, and a measurement circuit embodied to excite the exciter coil for producing an alternating magnetic field passing through the first receiving coil, the second receiving coil and the measured liquid. The receiving coils are influenced in different manner by the magnetic field induced by the alternating magnetic field in the measured liquid and directed counter to the alternating magnetic field. The measurement circuit is furthermore embodied to register an electrical signal of the receiving coils and to derive from such the electrical conductivity of the liquid.

Abstract: A device and method of use for measuring the electrical charge of flying insects. The inventive device comprises measuring the charge induced by a flying insect and measuring the average of charge deposited on a metal screen due to the impact of multiple of insects on the screen.

Abstract: An RF current probe is encapsulated in a conductive housing to permit its placement inside a plasma reactor chamber. An RF voltage probe is adapted to have a long coaxial cable to permit a measuring device to be connected remotely from the probe without distorting the voltage measurement.

Abstract: Transducer configurations and methods for transducer positioning in electrical impedance tomography are provided. A plurality of transducers for one electrical impedance tomography arrangement are configured for positioning proximate a surface of an object and spaced apart along the object, wherein the transducers are one or more conductive rings and have at least one non-conductive portion. The arrangement further includes one or more excitation drivers coupled to the plurality of transducers and configured to generate excitation signals for the plurality of transducers. The arrangement also includes one or more response detectors coupled to the plurality of transducers and configured to measure a response of the object at the plurality of transducers to the excitation applied by the plurality of transducers based on the excitation signals.

Abstract: The present invention provides a method of detecting and preventing grind burn from developing on a gear. The method includes performing acoustic emission testing while the gear is being ground during a grinding operation. The grinding wheel is evaluated during an eddy current test to detect material buildup on the grinding wheel which could cause grind burn. In addition, the method includes collecting swarf from the gear during the grinding operation and inspecting the swarf for an indication of grind burn.

Abstract: A method for in situ monitoring of a membrane of a membrane separation system comprises measuring a complex impedance of the membrane at a plurality of frequencies to provide an indication of the electrical conduction and electrical polarization properties of the membrane. The membrane based separation system for removing or reducing the concentration of materials carried in a fluid including a separation membrane has a first pair of electrodes separated by the membrane and arranged for measurement of the complex impedance of the membrane at a plurality of frequencies to provide the indication of the membrane properties. There may also be a second pair of electrodes separated by the membrane for injecting the stimulus current such that the injecting and monitoring functions are separated.

Abstract: A Data acquisition apparatus for measuring purpose can be used as a Digital Multi-Meter (DMM) as well as a LCR meter, and this apparatus can be implemented in semiconductor chip adopted in a handheld case, it includes a DMM and a LCR meter. The LCR meter includes a LCR measuring circuit implemented with integrated circuit. The LCR measuring circuit includes an impedance measuring circuit and an auto-zero amplifier which bias the input offset voltage and amplify the input signal that has passed a big resistor (PTC) to make the signal have a predetermined SNR suitable for the process by the LCR measuring circuit.

Abstract: One illustrative embodiment includes an apparatus for detecting if a fastener moves from a first position to a different second position. The apparatus includes a first connector for connecting a first side of a contact bridge to the fastener for movement in response to movement of the fastener, and a second connector for connecting a second side of the contact bridge to an object to remain stationary relative to the object. One of the first and second sides of the contact bridge includes first and second spaced apart electrical conductors; the other side includes a third electrical conductor. The third electrical conductor is positionable to contact the first and second electrical conductors when the fastener is in the first position, and the third electrical conductor may be spaced apart from at least one of the first and second electrical conductors when the fastener is in the second position.

Abstract: A position sensor that includes two coils, the first coil (transmitting coil) being fed a certain frequency such that it emits a constant electromagnetic field, and said field being received and/or detected by way of the second coil (receiving coil), is characterized in that the axis of the second coil is angled with respect to the axis of the first coil, preferably located at an angle of 90° with respect to the axis of the first coil.

Abstract: A method for determining a closing time of a valve having a coil drive, in particular a direct injection valve for an engine of a motor vehicle, has the steps: (a) switching off a current flow through a coil (L_inj) of the coil drive, so that the coil (L_inj) is depowered, (b) capturing a time curve (110) of a voltage induced in the non-powered coil (L_inj), wherein the induced voltage is generated by decaying eddy currents in a magnetic circuit of the coil drive and by a motion of the armature relative to the coil (L_inj), (c) evaluating the captured time curve (110) of the voltage induced in the coil (L_inj), and (d) determining the closing time based on the evaluated time curve (110). A corresponding device and a computer program for determining the closing time of a valve with a coil drive can be provided accordingly.

Abstract: A method for determining residual coupling of an inductive, conductivity sensor, in which the conductivity sensor is surrounded by a measured medium and an equivalent impedance of the medium is calibrated with a variable compensation impedance. The variable compensation impedance and the equivalent impedance of the medium act on a measuring coil of the conductivity sensor with a phase shift of 180°. In order to be able to perform a measuring of the residual coupling with a high accuracy of measurement at any time during operation of the conductivity sensor, the variable compensation impedance is varied until an output voltage of the measuring coil of the conductivity sensor assumes a minimum voltage; wherein the minimum voltage corresponds to the residual coupling of the inductive, conductivity sensor.

Abstract: Disclosed herein are embodiments of devices for measuring electrical current and related systems and methods for forming and using such devices. According to certain embodiments, devices according to the present disclosure may comprise Rogowski coils. Also disclosed are systems and methods for forming a current measuring device using a bobbin that may allow for the use of a continuous length of wire for all windings associated with the current measuring device. Automated manufacturing techniques may be utilized to facilitate the manufacture of devices for measuring electrical current and/or may reduce the cost of such devices. Various embodiments disclosed herein include the use of a bobbin that may be selectively configured between a linear configuration and a closed configuration. One or more current sensors disclosed herein may be utilized in connection with a motor management relay or other type of intelligent electronic device.

Abstract: Systems, devices and methods for sensing moisture within an electronic device are disclosed. A device may include a housing and a display defining an exterior of an electronic device and an interior of the electronic device. Further, the device may include an integrated circuit (IC) within the electronic device and a control element within the electronic device. The device may also include a moisture sensor such as an inductive sensor, a capacitance sensor, or both. The moisture sensor, which may be part of the IC, together with the control element may sense moisture within the electronic device.

Abstract: Embodiments relate to systems and methods for selecting circuit element values for a hybrid active power filter operating over a variable frequency. In aspects, a hybrid active power filter (HAPF) circuit can eliminate current harmonics present in an AC power source which are caused by an AC load network.—In implementations, the AC voltage source—may be a source having a variable frequency range, for instance 360-800 Hz. Since the source voltage can encompass a significant frequency range, a simple determination of the correct or desirable values of capacitive and inductive elements in the filtering section of the HAPF may not be possible. According to aspects, analytic techniques are provided which allow the values of those circuit elements to be derived from impedance and other circuit values to provide satisfactory suppression of identified harmonics, which can include the 5th, 7th, 11th, 13th, 17th, 19th, 23rd, 25th harmonics in the output voltage.

Abstract: A non-contact sensing module includes a coil printed circuit board in which a reference pattern coil may be formed at an upper surface and in which a sensing pattern coil may be formed at a lower surface and that has a mounting hole at the center, and a main printed circuit board that may be coupled to the mounting hole and that may be vertically disposed at an upper surface of the coil printed circuit board and that may be electrically connected to the reference pattern coil and the sensing pattern coil.

Abstract: Systems and methods of monitoring a rod control system of a nuclear power plant, including calculating impedance of at least one coil of a rod movement mechanism non-intrusively while the system is operating, comparing a measured impedance to a reference impedance, and determining if the measured impedance deviates from the reference impedance value by a predetermined amount to indicate degradation of the rod control system.

Abstract: Sensor devices and related methods disclosed. One example sensor device includes a Rogowski coil defining an aperture and a dielectric material at least partially enclosing the Rogowski coil. The dielectric material has a dielectric constant of at least about 3.5. The dielectric material is configured such that, when a conductor is at least partially inserted within the aperture, at least a portion of the dielectric material is positioned between the Rogowski coil and the conductor.

Abstract: For detecting within a communication range of an antenna a contactless data storage device which is configured for inductive coupling with an electromagnetic field emitted by the antenna, a return signal is detected (S1) at the antenna during emission of an electromagnetic field pulse. During amplitude build-up of carrier oscillation at the beginning of the electromagnetic field pulse, an evaluation signal is generated (S2) based on the return signal, and the data storage device is detected (S3) based on the evaluation signal. By detecting the presence of the data storage device based on an evaluation signal generated during amplitude build-up, the detection of the data storage device can be initiated before carrier oscillation of the electromagnetic field pulse is stable. Consequently, the width of the electromagnetic field pulse can be shortened and, therefore, energy consumption for detecting the presence of the data storage device can be reduced.

Abstract: A system for accounting for electromagnetic (EM) distortion with an EM tracking system includes a sensor array (144) configured to sense EM energy in a target volume. An EM sensing correction module (140) is configured to analyze data from the sensor array to detect EM distorters in the target volume. The EM sensing correction module is further configured to compare distortion fingerprints stored in a database (142) to identify a distortion source.

Abstract: The abnormality detection system is provided for detecting an abnormality of an object. The abnormality detection system includes a high-frequency power source, a primary coil, a secondary coil and a controller. The high-frequency power source supplies power. The primary coil receives the power supplied from the high-frequency power source. The secondary coil is mounted to the object in noncontact with the primary coil for receiving power supplied from the primary coil. The controller is operable to detect the power received by the secondary coil and also to determine whether or not an abnormality is present in the object based on the detected power.

Abstract: A metal detector (420) has a metallic enclosure (421) with entrance and exit apertures (430, 431) whose cross-sectional areas differ from each other. Inside the enclosure is a coil system with a transmitter coil (423) and first and second receiver coils (424, 425). The apertures and the coil system enclose a detection zone (428) around a travel path on which objects under inspection move. The asymmetric detection zone has a variable cross-section along the travel path and the coils differ in size from each other. The receiver coils are connected in series, but their windings are wired with the opposite sense of rotation relative to each other. Energizing the transmitter coil generates a primary electromagnetic field that induces a first voltage and a second voltage in the corresponding receiver coils. Despite the asymmetry, the respective voltages cancel each other when no metal is present in the object investigated.

Abstract: A method and device are disclosed for estimating a power demand level of an active circuit on a power supply line. A ripple amplitude and a ripple frequency associated with operation of the active circuit may be monitored on the power supply line. The ripple amplitude and ripple frequency may be compared with corresponding references. The ripple amplitude and ripple frequency may be associated with an estimated power demand level of the active circuit on the power supply line based on the comparison. A ripple generator generates a controlled ripple on the power supply line for calibration.

Abstract: In an electromagnetic induction type coordinate input device, on a substrate, plural first loop coils including loop portions are disposed in a first direction, and plural second loop are disposed in a second direction. The first and second loop coils include extraction line portions, each composed of a first line and a second line that are in parallel and are continuously connected to corresponding ones of the first and second loop coils. One of the first line or the second line of the first loop coil is connected to at least one of: (i) the first line or the second line of another one of the first loop coils, and (ii) a line of the loop portion of a second loop coil, within a position detection area, to form a common extraction line with (i) and/or (ii), to thereby reduce the overall number of extraction lines disposed on the substrate.

Abstract: An apparatus and method for detecting a foreign object in a wireless power transmitting system are provided. In a case in which a foreign object is not detected prior to charging, an attempt to detect a foreign object detection during charging is performed, and when a foreign object is not detected while a power signal is being received, power is limited based on a temperature sensor.

Abstract: The present invention is related to an apparatus and method for detecting a foreign object in a wireless power transmitting system. Specifically, a wireless power transmitting apparatus includes a primary core block which transmits wireless power to a wireless power receiving apparatus through magnetic induction or magnetic resonance; an electric driving unit applying an AC (Alternating Current) signal required for the primary core block to transmit the wireless power; a control unit being connected to the electric driving unit and generating a control signal for controlling the AC signal; and a current measurement unit measuring a current flowing into the primary core block and obtaining a current measurement value converted to a numeric value relevant for the control unit to analyze the current.

Abstract: The invention relates to a method for determining the piston position of a hydraulic or pneumatic piston cylinder unit, wherein the cylinder jacket and the piston form an electrical conducting path and the piston position is determined with the aid of the inductive and/or resistive properties of the conducting path that is formed. In addition, the invention relates to a piston cylinder unit having a measuring device for carrying out such a method.

Abstract: Disclosed is a test apparatus for efficiently and accurately testing a high frequency voltage dependency of an impedance of a test object without damaging the test object. The test apparatus includes a high frequency power source unit, a reference waveform generator, a matching device, an oscilloscope, a control panel, and a main control unit. The test apparatus may boost a high frequency pulse output at a relatively low power from the high frequency power source unit to a voltage required for a high frequency withstand voltage test to be applied to a test object in a state where impedance matching is performed between the high frequency power source unit and the test by the matching device, that is, under a tuned state. Whether the waveform of the voltage applied to the test object is a defined waveform may be concisely monitored and observed by the oscilloscope.