Abstract: A position detector which provides improved reference position detecting precision by stabilizing the output signal from magnetoelectric transducers in a reference position part. A rotor has a magnetized surface alternately provided with different magnetic poles and a reference positional part in which magnetic poles provided on the magnetized surface are partly omitted. A rotational angle sensor has MR elements laid out thereon in opposition to the magnetized surface of the rotor to output the voltage signal VS according to the magnetic field intensity in the magnetized surface due to the rotation of the rotor. A waveform processing circuit and a pulse signal processing signal shape the waveform of the voltage signal from the rotational angle sensor, and also generate the rotational angle pulse signal and a reference position pulse signal according to the waveform reforming signal.

Abstract: Diagnostics apparatus for detecting operation of an exciter circuit connected to an igniter, includes means for detecting current discharged from the exciter circuit through the igniter, means for detecting current discharged from the exciter circuit other that through the igniter, and means for producing a single output that indicates the type of discharge from the exciter circuit.

Abstract: An apparatus for measuring an electromagnetic field distribution using a focused electron beam can measure the electromagnetic field distribution in a specimen with high resolution and high reliability. A focused electron beam radiation system irradiates a specimen with a focused electron beam. A specimen tilt mechanism tilts a specimen by 180.degree. about a tilt axis that is perpendicular to the optical axis of the focused electron beam. An electron beam position detector measures the direction and quantity of the deflection given to the focused electron beam when it is transmitted through the specimen.

Abstract: A method of testing the position of an edit point between an edited magne tape packed in a cassette and a leader spliced ahead of the recording or a trailer spliced after the recording, includes determination of a distance of the edit point from a cue tone situated, for example, at least before the beginning of the recording, or from the end of the recording and generating first and second output signals commensurate with an optical measurement of the edit point and an inductive measurement of the recorded cue tone. In dependence of the position of the recorded cue tone behind the leader or ahead of the trailer as viewed in tape travel direction, a time difference, such as, between the ascending flank of the second output signal and the descending flank of the first output signal, is determined. The determined time difference is then compared with upper and lower limits which define a tolerance range for the position of the edit point before or behind the recorded cue tone.

Abstract: Methods of operation of different types of multiple electrode apparatus vertically disposed in a cased well to measure information related to the resistivity of adjacent geological formations from inside the cased well. The multiple electrode apparatus have a minimum of three spaced apart voltage measurement electrodes that electrically engage the interior of the cased well. Measurement information is obtained related to current which is caused to flow from the cased well into the adjacent geological formation. First compensation information is obtained related to a first casing resistance between a first pair of the spaced apart voltage measurement electrodes. Second compensation information is obtained related to a second casing resistance between a second pair of the spaced apart voltage measurement electrodes. The measurement information, and first and second compensation information are used to determine a magnitude related to the adjacent formation resistivity.

Abstract: High-energy permanent magnetic materials are characterized by exposing the material to sequential pulsed fields of respectively different rates of change of magnetic field strength, sensing the total magnetic field strength, sensing the total magnetic field generated in the sample by the respective pulses including eddy currents induced therein, and eliminating eddy current components from the said fields, whereby the net magnetic fields relate to the magnetic characteristics of the sample. Preferably the pulsed field is capacitor-generated via a solenoid and the rate of change of the magnetic field strength is produced by holding the waveform constant and altering the pulse duration, for example by providing taps on the solenoid together with an inductor and a balancing resistor, to enable the ratio of resistance to inductance to be maintained substantially constant across the range of taps utilized.

Abstract: A nuclear magnetic resonance imaging scheme for imaging living body information related to the physiological function change in the living body. In this scheme, the pulse sequence realizes a first imaging scheme sensitive to functional information of the body to be examined and a second imaging scheme insensitive to the functional information of the body to be examined so as to obtain first and second types of the nuclear magnetic resonance images corresponding to the first and second imaging schemes, respectively, by a single execution of this pulse sequence. The functional information of the body to be examined is then obtained by processing the first and second types of the nuclear magnetic resonance images.

Abstract: A method and apparatus used in providing resistivity measurement data of a sedimentary subsurface for developing and mapping an enhanced anomalous resistivity pattern. The enhanced subsurface resistivity pattern is associated with and an aid for finding oil and/or gas traps at various depths down to a basement of the sedimentary subsurface. The apparatus is disposed on a ground surface and includes an electric generator connected to a transmitter with a length of wire with grounded electrodes. When large amplitude, long period, square waves of current are sent from a transmission site through the transmitter and wire, secondary eddy currents are induced in the subsurface. The eddy currents induce magnetic field changes in the subsurface which can be measured at the surface of the earth with a magnetometer or induction coil. The magnetic field changes are received and recorded as time varying voltages at each sounding site.

Abstract: To suppress and compensate influences of disturbance variables, a method of calibrating a sensor is disclosed, in which at most as many so-called influence variables influencing the measuring result are considered as measurable quantities are detected by the sensor, the set of the influence variables being composed of at least one disturbance variable influencing the measurement and at least one target quantity to be determined from the measurable quantities.

Abstract: A device for measuring rotation which is mounted into a wheel bearing. The device is substantially composed of a transducer arranged around the axis or rotation of the part performing the rotation, and of a signal generator ring which is part of a hollow-cylindrical or bowl-shaped signal generator component part. The signal generator ring is supported rotatably on a cylindrical part of the transducer.

Abstract: In a preferred embodiment, a magnetoresistive (MR) position sensor, including: a rotatable cylindrical encoder wheel having a plurality of alternating N and S magnetic poles spaced a constant pole pitch around the circumferential surface of the encoder wheel, adjacent ones of the N and S poles having interfacing edges parallel to the axis of rotation of the encoder wheel; a first MR sensing array disposed on an insulative substrate in proximity to the circumferential surface of the encoder wheel, such as to sense rotating magnetic fields produced by the N and S poles as they pass the first MR sensing array as the encoder wheel rotates, the first MR sensing array including at least a first section comprising at least two legs extending parallel to the interfacing edges, the at least two legs being joined in series so as to form a serpentine shape; apparatus to apply a constant DC voltage across terminal ends of the serpentine shape.

Abstract: The monitoring device for structural elements, in particular for tension members of soil or rock anchors, compression members of poles, prestressing elements for prestressed concrete structures and bridge cables has at least one sensor conduit (15) disposed inside or outside of a structural element (1) for receiving at least one sensor (16), wherein the sensor (16) is disposed movably and/or releasably in the sensor conduit (15). An evaluation device (18) determines the presence of corrosion, cracks, overloads, overextensions and tension relaxation from the at least one sensor signal.

Abstract: A displacement sensor provided with a magnet (4) and magnetoelectric conversion element for sensing the variation of magnetism caused by the magnet to sense the displacement of the magnetic material to be measured, which includes a first magnetoelectric conversion element (5) located in the place where the magnetic flux density is varied by the displacement of the material to be measured (7), a second magnetoelectric conversion element (6) of the same kind as the first magnetoelectric conversion element (5) located in the place where the magnetic flux density is not varied by the displacement of the material to be measured, and a circuit element (10) for adding the outputs of the first and second magnetoelectric conversion element at a predetermined ratio of V20/V10, wherein V20 and V10 are outputs from the first and second magnetoelectric conversion elements, respectively, for a displacement of 0 at a temperature of 20.degree. C.

Abstract: A mixing device for the mixing of fluid measuring samples in an NMR measuring device, whereby the measuring device includes a rod (10) which is arranged coaxially to the main field magnet coil of the NMR measuring device to be movable in the axial direction and, on one end, exhibits a piston projecting into the measuring sample and, with the assistance of a drive coil (8) arranged at the end facing away from the measuring sample, is moved in the axial direction when current flows through the drive coil (8), wherein a spring element (7) is provided to move the rod (10) into a rest position when no current flows through the drive coil (8), is characterized by the drive coil (8) being arranged, in an axially movable fashion, in the inhomogeneous region of the magnetic field produced by the main field magnet coil coaxial to the main field magnet coil, the drive coil (8), on one axial end, being rigidly connected to the rod (10) and, on the end facing away from the rod (10), being connected, via the spring element

Abstract: A method is described for testing for slider/disk contact in a disk drive comprising a rotating disk and a head mounted by an actuator for selective positioning of the head over the disk, the head having a slider, and a spindle motor for rotating the disk. The method comprises the steps of providing power to the spindle motor to cause rotation of the disk at a preselected rotational velocity corresponding to a rotational velocity designed for the disk during normal read/write operation, and thereafter withdrawing the power from the spindle motor such that the disk spins down to zero rotational velocity. While the disk spins down to zero rotational velocity, an acoustic coupling is formed between an acoustic emission sensor having an electric output and the spindle motor to provide first electric signals representative of acoustic emissions from the spindle motor, including acoustic emissions caused by slider/disk contact.

Abstract: An apparatus for use in determining the thickness of the insulated coating of an electrical cable manufactured in an extrusion process having means for generating an alternating current in the cable core coupled with means for detecting the magnetic field produced by the current flow in the cable such that in combination with a measurement of the distance from the detection means to the coated cable surface, a determination of coating thickness may be made.

Abstract: A position detector includes a magnetic recording medium on which a prescribed magnetic pattern has been formed, a magnetoresistive element the amplitude value of which varies in response to the magnetic pattern, an amplifier for amplifying the output of the magnetoresistive element, the offset voltage of the amplifier output being variable, and an output observing element for observing the output of the amplifier. The offset voltage of the amplifier is set based upon the results of observation provided by the output observing element. Adjustment of the offset voltage is thus set automatically.

Abstract: In a method for drilling adjacent to a cased known first borehole a second borehole in a predetermined direction the following steps are carried out for a number of along hole depths d.sub.i :measuring components of gravity acceleration and magnetic field (earth & casing);determining direction parameters .alpha..sub.i ;deriving magnetic polestrength components, B.sub.p1,i and B.sub.p2,i ;applying B.sub.p1,i /B.sub.p2,i =s.sub.1,i /s.sub.2,i and determining deviations of the predetermined direction; andcontrolling drilling direction of the second borehole.

Abstract: A nondestructive inspecting apparatus is arranged to have an exciting magnet for applying an ac magnetic field to a sample and a SQUID for converting change of a magnetic characteristic of the sample occurring when the ac magnetic field is applied to the sample into an electric signal. The exciting magnet is a cancelled coil assembly composed of plural coils having respective polarities.

Abstract: A magnetic assembly for detection and authentication of magnetic documents. The magnetic assembly includes a permanent magnet (PM), first and second magnetically soft high permeability pole pieces shaped to form a tapered, variable gap size magnetic circuit with the permanent magnet. The PM is located at a first gap between the first and second pole pieces. A magnetoresistive (MR) sensing element is located at or near the center of a second gap between said first and second pole pieces. The second gap and MR sensing element are proximate a magnetic document to be sensed. An electrical conductor is adjacent to the MR sensing element, but is electrically insulated therefrom.