Abstract: In order to measure magnetic characteristics of a sample, the latter is positioned above the SQUID so that both the SQUID and the sample are supported in a vessel in a gaseous nitrogen space above a liquid nitrogen coolant so that the measurement can take place at ambient pressure and in a nitrogen atmosphere.

Abstract: Apparatus and methods for measuring cross sectional area and flaws in a continuous sucker rod string as the string is conveyed within a borehole. These measured parameters are useful is monitoring the physical integrity of the sucker rod string. A magnet is used to saturate an increment of continuous sucker rod, and a coil is used to measure induced flux. Cross sectional area of the rod increment is computed from the flux measurement. One or more Hall effect transducers are used to measure leakage from the increment as a function of distance along the increment. This measurement is used to detect and quantify the type of flaw within the rod increment being investigated. The process is repeated as the sucker rod string is conveyed into or out of the borehole.

Abstract: A measuring travel instrument has a frame composed of a permeable material, a magnet situated inside the frame in a movable fashion, a magnetosensitive sensor situated in a slot of the frame that is situated in a closed magnetic circuit in such a fashion that a size of a magnetic flux of the magnet changes in it depending on a position of the magnet, a sled composed of a magnetically impermeable material and executing a sliding movement, the magnet being located in the sled, a guide member extending through a recess in the frame and connecting the sled with a component a movement of which is to be determined, the guide member composed of a permeable material and arranged in such a way that it forms a part of the frame conducting the magnetic flux of the magnet.

Abstract: Systems and methods for detecting the magnetic field created by a magnetic target. An arrangement of multiple magnetic field sensing elements and circuit elements configured to select and/or interpolate between the sensing elements to give enhanced performance and to compensate for external mechanical factors. The circuit arrangement is integrated on a single silicon chip to form an integrated circuit sensing device in one embodiment.

Abstract: An electromagnetic wave propagation resistivity borehole logging system comprising multiple groups of electromagnetic transmitter-receiver arrays operating at three frequencies. The borehole logging tool component of the system employs eight transmitters and four receivers. The transmitters and receivers are disposed axially and symmetrically along the major axis of the tool to form four group pairs. Each group pair consists of a transmitter-receiver groups axially and symmetrically on opposing sides of a reference point on the tool. Each, transmitter-receiver group consists of one transmitter assembly and two receiver assemblies. Each transmitter-receiver group is operated at two of three operating frequencies which are 100 kHz, 400 kHz and 2 MHz. Some of the transmitter and receiver assemblies are fabricated to yield azimuthally focused resistivity measurements, and to yield vertical and horizontal resistivity in anisotropic dipping beds.

Abstract: An inspection system include a transmitter and a receiver configured for communication with a remotely positioned processing means. The transmitter and receiver are arranged as a mobile apparatus configured for insertion into any duct, conduit, pipeline, mining shaft, or the like, or any diameter or cross section. The transmitter is configured to transmit an electromagnetic signal to induce an electromagnetic response in the duct and the electromagnetic response is detected by the receiver. The mobile apparatus is self-powered and processes the electromagnetic response prior to communicating the processed response to the remotely positioned processing means as a discrete signal.

Abstract: A magnetic sensor device has a magnetic sensor having a magnetic material whose threshold frequency is changed by a magnetic field to be detected, and the device has the so-called electromagnetically-coupled current path which is affected by the magnetic material in order to electrically detect the threshold frequency of the magnetic material. The current path is connected to an oscillator circuit, which is set so that its oscillation frequency is changed by a change in the threshold frequency of the magnetic sensor. In the magnetic sensor device, the magnetic field to be detected causes a change in the oscillation frequency of the oscillator circuit, and the change in the frequency is extracted as a magnetic field detection signal.

Abstract: A disc stabilizer for use in a spin-stand tester having a spindle motor for rotating a disc is provided. The spin-stand tester is capable of positioning a transducing head adjacent a first surface of the disc. The disc stabilizer includes a vacuum plate coupled to a spindle of the spindle motor. The vacuum plate has a top surface and a bottom surface opposite the top surface. At least one of the top and the bottom surfaces is a grooved surface including multiple vacuum channels. The grooved surface is substantially in contact with a second surface of the disc. Vacuum distributed through the multiple vacuum channels of the grooved surface is applied directly to the second surface of the disc, thereby holding the disc in place.

Abstract: According to the invention there is provided a pulse signal generator comprising a plurality of magnetic elements arranged in an imaginable plane and capable of producing large Barkhausen jumps; a first unit for generating a magnetic field, which is changed by the object to be detected to cause the magnetic elements to produce the large Barkhausen jumps, the first unit consisting of a pair of magnet/yoke combinations provided on opposite sides of said imaginable plane such that their poles are oriented in opposite directions, forming a detecting area at an end thereof; a second unit for detecting the large Barkhausen jumps to produce corresponding pulse signals; and first and second adjusting yokes being movable on one of the magnet/yoke combinations along one of the magnetic elements and on the other of the magnet/yoke combinations along the other of said magnetic elements, respectively.

Abstract: Single coil to be excited by a predetermined A.C. signal is provided, with no secondary coil being provided. Magnetism-responsive member is movable relative to the coil so that a self-inductance of the coil progressively increases or decreases in response to displacement of an object to be detected within a predetermined range and a voltage of the coil corresponding to the self-inductance is produced. Predetermined reference voltage is generated and subjected to analog operations with the coil output voltage, to thereby generate first and second A.C. outputs having, as amplitude coefficients, first and second cyclic amplitude functions correlated to the position to be detected. The position is detected on the basis of the phase component of the amplitude coefficient functions. Combination of two coils and one reference voltage may be employed.

Abstract: A non-contact displacement detecting device including a permanent magnet fixed with a rotational member, a sensor portion fixed with a non-rotational member, and the sensor portion detects a displacement of a detected object connected with the shaft. The non-contact displacement detecting device includes a housing for supporting the rotational member rotatably and restricting one movement of the rotational member in an axial direction, and a holder for contacting with the rotational member at a plurality of contact points and restricting another movement of the rotational member in the axial direction. Thereby, the movement of the rotational member in the axial direction is restricted by the holder and the housing.

Abstract: An eddy current inspection probe for inspecting a preselected surface. The eddy current inspection probe includes an expandable element at least partially defining an interior space which is expandable by introducing a pressurized fluid into the interior space from a collapsed position to an expanded position for contacting the preselected surface of the component for inspecting the surface. The probe also includes an eddy current array positioned over the expandable element for generating and detecting magnetic fields in the component to inspect the preselected surface.

Abstract: A modular waveguide assembly for use in a position sensor promotes efficient manufacturing, and can be tested and handled separately from the electronics module of the sensor. The waveguide assembly includes a channel having an opening extending along its length, a waveguide located within the channel, a conductor located within the channel, and a mode converter, such as a coil, located within the channel and positioned to generate an electrical signal from a signal traveling along the waveguide. A damping material can be inserted into the channel opening and around a portion of the waveguide such that the material adheres to the waveguide. Preferably, the damping material is at least initially partially flowable, and is then cured.

Abstract: This invention is a method for nondestructively determining the deterioration of determining ferromagnetic materials by quantifying the change in brittleness with aging of the materials. This invention supposes acquirement of an embrittlement coefficient b by measuring a magnetic susceptibility &khgr;b of ferromagnetic materials under a magnetic field having a specified intensity H. And the coefficient b of the ferromagnetic materials is calculated by putting the intensity H and the susceptibility &khgr;b into an equation: b=&khgr;bH2. By the coefficient b, a correlation between the coefficient b and a referenced embrittlement factor of materials like said determining materials is obtained previously. The coefficient b of the determining materials in the initial and the deteriorated states is acquired. The factor corresponding to the coefficient b is obtained from the correlation. It is possible to quantify the change by comparing the values of the factor in the initial and deteriorated states.

Abstract: Transceiver and methods are included that are especially suitable for detecting metallic materials, such as metallic mines, within an environment. The transceiver includes a digital waveform generator used to transmit a signal into the environment and a receiver that produces a digital received signal. A tracking module preferably compares an in-phase and quadrature transmitted signal with an in-phase and quadrature received signal to produce a spectral transfer function of the magnetic transceiver over a selected range of frequencies. The transceiver initially preferably creates a reference transfer function which is then stored in a memory. Subsequently measured transfer functions will vary depending on the presence of metal in the environment which was not in the environment when the reference transfer function was determined. The system may be utilized in the presence of other antennas, metal, and electronics which may comprise a plastic mine detector for detecting plastic mines.

Abstract: To provide a bearing sensor having a thin plane coil for applying a biasing magnetic field and at least one magneto resistive element pair (a first magneto resistive thin plate and a second magneto resistive thin plate) crossing opposed conductor sides of the coil. The plane coil has at least one pair of opposed conductor sides (a first side and a second side). The first magneto resistive thin plate and the first side cross one another at an angle more than 30 degrees and less than 90 degrees. The second magneto resistive thin plate and the second side cross one another at an angle more than 30 degrees and less than 90 degrees. While biasing magnetic fields in opposite directions are applied to the magneto resistive thin plates, respectively, intermediate potentials of the magneto resistive element pair are measured to determine bearings based on the difference between the intermediate potentials.

Abstract: In a superconductive quantum interference element comprising Josephson joints, a washer coil and a detecting coil constituting a superconductive loop and a feedback modulation coil, to provide a superconductive quantum interference element capable of promoting spatial resolution by preventing an effective detection area of the detecting coil from enlarging even when a width of a superconductive wiring constituting the detecting coil and a superconductive film at a vicinity of the detecting coil are larger than an inner diameter of the detecting coil, there is constructed a superconductive quantum interference element having a structure provided with a slit at a detecting coil and/or a superconductive film at a periphery of the detecting coil.

Abstract: A magnetic disk certifier includes a defect detector circuit comprising a low-pass filter for extracting a low frequency component of the read-out signal, the low frequency component containing a signal component of the error, a signal generator circuit for generating a signal having a predetermined frequency lower than the frequency of the read-out signal, a synthesizer circuit for synthesizing an output signal of the low-pass filter and the signal outputted from the signal generator circuit and a comparator for generating an error signal by comparing the synthesized signal from the synthesizer circuit with a predetermined reference level.

Abstract: A position transducer including a scale and magnetic sensor system consisting of a first sensor unit and second sensor unit disposed in different positions in a direction (Z-direction) perpendicular to a moving direction (X-direction) of the magnetic sensor relative to the scale. The first and second sensor units are driven in phase with each other with a high frequency signal, and a difference between outputs of these two sensor units is determined in order to detect a relative position of the magnetic sensor to the scale.

Abstract: A system for tracing routes of conductors has a transmitter (10) for applying an alternating signal (11) to the conductor to be traced (12), and the field produced by this signal is detected remotely from the conductor. In order to distinguish between the field produced by the conductor being traced and the fields produced by nearby conductors (14) due to capacitive coupling (17), the alternating signal has phase-locked first and second components with frequencies F1 and F2 respectively, related by N×F1=M×F2, where N and M are non-adjacent integers greater than 1, one of which is odd and one of which is even, having no common factors. The field is detected at a plurality of positions. The phase relationship of the detected signals is investigated to determine unambiguously the position of the object concerned.