Abstract: Method for nondestructive and noncontact detection of faults in a test piece, with a transmitter coil arrangement with at least one transmitter coil that transmits periodic electromagnetical AC fields to a test piece, a receiver coil arrangement with at least one receiver coil for detecting a periodic electrical signal having a carrier oscillation whose amplitude and/or phase is modulated by a fault in the test piece. A signal processing unit produces a useful signal from the receiver coil signal, and an evaluation unit evaluates the useful signal to detect a fault in the test piece. A self-test unit undertakes systematic quantitative checking of signal processing functions of the signal processing unit and/or of the transmitter coil arrangement and/or of the receiver coil arrangement and/or upon external request undertakes calibration of the signal processing unit using a calibration standard which replaces the transmitter coil arrangement and/or of the receiver coil arrangement.

Abstract: A device for nondestructive and noncontact detection of faults in a test piece, with a stationary measurement device (16) for taking an eddy current or a magnetic stray flux measurements on a test piece (10) continuously advanced relative to the measurement device; and a device (12) for positioning the test piece with respect to the measurement device in a plane perpendicular to the direction of movement of the test piece. The device also has a monitoring unit (20) with at least three distance sensors (22) arranged distributed around the test piece in the peripheral direction for contactless detection of the distance between the surface of the test piece facing the respective sensor and the respective sensor, as well as a unit for evaluating the signals from the sensors.

Abstract: A process and device for detecting electrically conductive particles in a liquid flowing in a pipe section, the liquid being exposed to periodic alternating electromagnetic fields by a transmitter coil which induces eddy currents in the particles, a probe made as a coil arrangement and which has an effective width producing a periodic electrical signal based on the eddy currents. The signal ha a carrier oscillation with an amplitude and/or phase which is modulated by particles passing across the effective width of the coil arrangement, the probe signal being filtered by a frequency-selective first filter unit, the filtered signal being sampled by a triggerable A/D converter stage to obtain a demodulated digital measurement signal, the digital measurement signal being filtered by a digital, frequency-selective adjustable second filter unit to obtain a useful signal, and the useful signal being evaluated to detect passage of electrically conductive particles in the pipe section.

Abstract: Apparatus and associated method for identifying defects on objects provide for—under computer driving—the AC voltage energization of at least one transmitting coil to be simultaneously effected by a carrier signal, and for an essentially amplitude-modulated received signal to be received by means of at least one receiving coil; what is carried out, furthermore, is a demodulation not only of the carrier signal contained in the received signal by means of magnitude and phase formation, but also a demodulation of the harmonics of the carrier which are contained in the received signal, likewise by means of respectively associated magnitude and phase formation, to be precise preferably by using a Fourier or wavelet transformation method.

Abstract: Method for nondestructive and contact-free detection of faults in a test specimen which is moved relative to a probe that detects a periodic electrical signal having a carrier oscillation whose amplitude and/or phase is/are modulated by any fault in the test specimen. The probe signal is filtered and sampled by a triggerable A/D converter stage to obtain a demodulated digital measurement signal which is filtered using a digital frequency-selective adjustable second filter unit to obtain a useful signal which is evaluated to detect a fault in the test specimen. The A/D converter stage is triggered at a fraction of the frequency of the carrier oscillation selected as a function of the fault frequency obtained as the quotient of the relative speed between the test specimen and the probe and the effective width of the probe, and the frequency-selective second filter unit is adjusted as a function of the fault frequency.

Abstract: A device for detecting electrically conductive particles in a liquid flowing in a pipe section, with a transmitter coil surrounding the pipe section for inducing eddy currents in the particles, at least one first inductive receiver coil surrounding the pipe section and a second inductive receiver coil which is spaced axially to the first receiver coil and which surrounds the pipe section, the first and the second receiver coils being located in the region of the transmitter coil and being subtractively connected, in order to output a difference signal according to the eddy currents induced by the transmitter coil, and the transmitter coil forming the primary side and the receiver coils forming the secondary side of a transformer arrangement. An evaluation unit evaluates the difference signal in order to detect passage of electrically conductive particles in the pipe section.

Abstract: A device for efficient transmission of electrical energy and/or information is built in the manner of a rotary transformer. The cores of this device are made of ferromagnetic rings of a U-shaped cross section of soft iron, or of soft iron core stacks of annular or hollow cylindrical shape, the ring-shaped or hollow cylindrical sheets typically being unslotted. There can be several coil sets within such a device; in this way several channels can be made available for parallel transmission of electrical energy and/or information.

Abstract: Apparatus and associated method for identifying defects on objects provide for—under computer driving—the AC voltage energization of at least one transmitting coil to be simultaneously effected by a carrier signal, and for an essentially amplitude-modulated received signal to be received by means of at least one receiving coil; what is carried out, furthermore, is a demodulation not only of the carrier signal contained in the received signal by means of magnitude and phase formation, but also a demodulation of the harmonics of the carrier which are contained in the received signal, likewise by means of respectively associated magnitude and phase formation, to be precise preferably by using a Fourier or wavelet transformation method.

Abstract: Method for nondestructive and contact-free detection of faults in a test specimen which is moved relative to a probe that detects a periodic electrical signal having a carrier oscillation whose amplitude and/or phase is/are modulated by any fault in the test specimen. The probe signal is filtered and sampled by a triggerablie A/D converter stage to obtain a demodulated digital measurement signal which is filtered using a digital frequency-selective adjustable second filter unit to obtain a useful signal which is evaluated to detect a fault in the test specimen. The A/D converter stage is triggered at a fraction of the frequency of the carrier oscillation selected as a function of the fault frequency obtained as the quotient of the relative speed between the test specimen and the probe and the effective width of the probe, and the frequency-selective second filter unit is adjusted as a function of the fault frequency.

Abstract: The invention relates to a process for testing of a workpiece by means of eddy currents induced by a field coil in the workpiece and from which a measurement signal is obtained by means of a measurement sensor, a pattern signal representative of a workpiece fault being generated, a correlation function of the measurement signal acquired by the sensor with the pattern signal being determined, and the correlation function being evaluated in order to detect a fault in the workpiece. The invention furthermore relates to a device for executing the process.

Abstract: A device for precision measurement of shafts, spindles, or the like calls for two surfaces which are combined with one another, of which one is partially reflecting and the other is roughly fully reflecting. These surfaces reflect an incident light beam independently of one another onto a single optoelectronic target. The target can be read out two-dimensionally and is pixel-oriented. From only a single measurement position, the azimuth and elevation, and the parallel offset between the incident light beam and a center of the reflecting surfaces can be determined.

Abstract: The effectiveness of a method for checking for exact alignment of two successive shafts, axles or the like is improved by the fact the no measures with respect to linearization or temperature compensation are necessary any longer by using a light-sensitive array as the light-sensitive sensor. The effects of outside light and reflections can be suppressed. The cross section and the quality of a detected laser beam can be checked especially by visual inspection. Production of the corresponding device for executing this process is facilitated. By using matched beam splitters and reflectors as well as light sources of different colors the number of optoelectronic sensors necessary can be significantly reduced.