Abstract: A rotation detecting device for detecting a rotating object includes a housing having a bearing and an mounting surface, a rotor member having magnetic peripheral portion and a rotary shaft that is supported by the bearing, a biasing permanent magnet for providing magnetic field around the mounting surface and the magnetic peripheral portion, an IC sensor chip including plural magnetic sensor elements disposed on the mounting surface to provide a sensing signal related to change in magnetic field around the sensor elements, and an IC signal processing chip that provides a rotation signal according to the sensing signal. In this device, the bearing and the mounting surface are integrally formed into the housing at a prescribed distance to secure an unchanged air gap distance.

Abstract: A bicycle signal output device comprises a magnet structured to be mounted to one of a first part and a moving part of a bicycle, a coil structured to be mounted to the other one of the first part and the moving part of the bicycle, and a signal generating unit that operates using electrical power generated by the coil in response to relative motion between the magnet and the coil.

Abstract: A proximity detector has a sequential flow state machine to identify states associated with a magnetic field signal provided by a magnetic field sensing element. The proximity detector can include a vibration processor to identify a vibration in response to the states.

Abstract: A resistivity sub including a resistivity sensor forms part of a bottom hole drilling assembly. The sensor is maintained at a substantially fixed offset from the wall of a borehole during drilling operations by, for example, a stabilizer. In WBM, galvanic sensors may be used, with or without commonly used focusing methods, for obtaining a resistivity image of the borehole wall. In OBM, capacitive coupling may be used. The apparatus is capable of using other types of sensors, such as induction, MPR, shielded dipole, quadrupole, and GPR sensors.

Abstract: The present invention provides an integrated circuit and a method for noise removal in a magnetic nano-particle sensor device. The method of the present invention comprises the steps of sending a conductor current through a conductor to generate a first horizontal magnetic field component at the location of a magneto-resistive sensor. In a further step the optimal operation point of the magneto-resistive sensor is determined by minimizing the noise at the output of the magneto-resistive sensor by means of a noise optimization circuit. By applying an external magnetic field such that nano-particles in the vicinity of the sensor are vertically magnetized, a second horizontal magnetic field component is generated at the location of the sensor. Then, the conductor current is adjusted such that the first horizontal magnetic field component compensates for the second horizontal magnetic field component.

Abstract: A non-destructive method of narrowing down the location of a failure in a sample includes a first step of acquiring first and second images of magnetic-field distributions obtained by scanning a laser beam irradiating first and second samples, respectively, and if there is a difference between the first and second images of the magnetic-field distributions, a second step of acquiring first and second current images from magnetic-field distributions acquired by scanning the first and second samples by a magnetic-field detector in a state in which a prescribed location on the first and second samples is being irradiated by the laser beam. The difference between the first and second current images is found and, based upon the difference image found, it becomes possible to identify a disparity in current paths relating to the prescribed location on the first and second samples.

Abstract: With a method for the contactless determination of a thickness of a layer (20) made of electrically-conductive material of a component (17), a sensor composed of a coil form (13) and a coil (14) is positioned in the vicinity of the component (17) to be measured. The method is based on a combination of the principles of induction and eddy current. The thickness of the layer (20) is determined using a plurality of measuring and evaluation steps in which the coil (14) is acted upon with a first alternating current frequency f1 and a second alternating current frequency f2, and its change in inductance is evaluated. The distance between the coil form (13) and, therefore, the coil (14), and the component (17) is derived from the inductance value of the coil (14) acted upon with the second alternating current frequency f2.

Abstract: The invention relates to a device for detecting movements and/or positions of an object with the aid of voltage pulses induced by the field of adjacent magnets (6, 7) in a coil (4). In order to generate a sufficiently strong signal also at small relative speeds between the magnets (6, 7) and the coil (4), the coil (4) encloses a spring (5) in which a quick fore-and-aft movement can be induced by the magnetic fields of the magnets (6, 7), the magnetic poles of the spring (5) being reversed during said fore-and-aft movement.

Abstract: In a SQUID magnetometer, high resolution, a high slew rate, and a high dynamic range are achieved without using expensive circuit components having a large number of processing bits and enabling a high speed processing operation. A digital FLL circuit using a double counter system is provided. This circuit utilizes two or more counters, for example, a change range counter in a digital FLL for carrying out a processing operation at a high speed and a reproducing counter in a control/measuring computer. In addition, in the present invention, hysteresis characteristics having a 1?0 positive margin is used. That is, a change of a state of a magnetic flux is counted by means of a counter. At the time of this change, control is made so as to track a different channel between cases in which a magnetic flux increases and decreases, thereby stabilizing the control.

Abstract: Magnetic field sensors, each generating an electrical output signal in proportion to the local magnetic field, are lithographically fabricated on a semiconductor substrate with a small spatial separation. The lateral dimension of the sensors and the separation length are the order of the minimum lithographic feature size. Comparing the electrical signals to the sensors results in a measurement of the local magnetic field gradient. Large field gradients, that vary on a small spatial scale, may be associated small magnetic structures such as microscopic magnetic particles. Detection of a field gradient can be used to infer the presence of a magnetic particle.

Abstract: A device for testing a test specimen for surface faults is equipped for delivering a magnetic flux into the specimen and has induction probes measurement sensors. At least two yoke legs have opposed gap-forming ends with oppositely poled exciter coils between which the test specimen can be guided. Outside ends of the yoke legs opposite the gap-forming ends are connected to one another by a magnetic flux conductor so that the magnetic flux runs perpendicular to the lengthwise direction through the test specimen. To adapt to test specimens of different cross section, the yoke legs can be moved and fixed. Testing of test specimens by means of high-energy magnetic alternating fields improved because the high heat losses produced in this process are adequately dissipated. The device is especially well suited to determine the quality of bars, pipes and the like in a hot rolling mill with high-energy alternating magnetic fields.

Abstract: A Hall Effect switching circuit and apparatus and method using the same are disclosed. The Hall Effect switching circuit comprises a power supply device, a Hall Effect detecting device and a buffer. The power supply device provides operation power to the Hall Effect detecting device. The Hall Effect detecting device provides a first triggering signal to a first output pin and a second triggering signal to a second output pin in accordance to a magnetic field through the Hall Effect detecting device. The buffer receives and buffers the voltage levels of the first/second triggering signals.

Abstract: Sensor assemblies including transmitter and receiver antennas to respectively transmit or receive electromagnetic energy. The sensor assemblies are disposed in downhole tools adapted for subsurface disposal. The receiver is disposed at a distance less than six inches (15 cm) from the transmitter on the sensor body. The sensor transmitter or receiver includes an antenna with its axis tilted with respect to the axis of the downhole tool. A sensor includes a tri-axial system of antennas. Another sensor includes a cross-dipole antenna system.

Abstract: The present invention is a device for and method of viewing a magnetic pattern recorded on magnetic media. The device includes a base. The base has an opening and includes registration marks for aligning the magnetic media as desired. The base is attachable to a viewer. A guide is connected to the base so that it slides within the opening in the base. The guide also has an opening. An inflatable bladder is attached to, and under, the guide. The inflatable bladder fills the opening in the guide. A holder is attached to the base so that it can slide along the base and be closed onto the guide. The holder also includes an opening. A magnetic garnet film is set within the opening in the holder. A magnetic media is placed on the guide. The holder is closed onto the magnetic media and the guide. The inflatable bladder is inflated so that the magnetic media is brought into physical contact with the magnetic garnet film. The pattern on the magnetic media is transferred onto the magnetic garnet film.

Abstract: A method and an apparatus are disclosed, to screen patients or other areas for ferromagnetic objects, particularly for use intra-operatively in an operating room. The device comprises at least one magnetic field source, at least one magnetic gradiometer, and the associated electronics. The field source and the gradiometer are supported by an arm structure which can be manipulated to position the field source and the gradiometer at one or more positions near areas of interest, such as areas on a patient or other subject, and to orient the field source and the gradiometer so that the axis of the magnetic field is arranged along three different non-parallel, non-coplanar, axes to ensure detection of any ferromagnetic object regardless of its shape and orientation. The device can be manipulated to place the sensor arrays in close proximity to selected parts of a subject's body, for screening purposes.

Abstract: An induced current position transducer reduces spatial phase errors associated with layout constraints. Each winding of the transducer comprises a set of loops arranged in hypothetical basic polarity zones that alternate along the measuring axis and a set of loops arranged in hypothetical offset polarity zones that are offset from the basic polarity zones along the measuring axis. Hypothetical offset zones are defined at positions where basic and offset polarity zones that have opposite polarities overlap. Due to layout constraints, each winding may have an offset zone including an unbalancing coupling area that differs from the coupling area in the majority of offset zones. The windings are configured such that the amount of unbalanced coupling area included in the offset zones of each respective winding is approximately the same for each of the windings, making their respective phase errors approximately the same.

Abstract: The invention relates to a sensor for detecting the direction of a magnetic field in a plane whose direction can be defined by the indication of a polar angle ?. Said sensor comprises a number of n magnetic field sensors (3.0 to 3.7). A measurement axis (8.1 to 8.4) is assigned to each magnetic field sensor in such a manner that the absolute value of the output signal of the magnetic field sensor is largest when the magnetic field runs parallel to the measuring axis. All measuring axes intersect at a common point (5). The number k of measuring axes is equal to at least three. An operating mode is provided during which two magnetic field sensors are selected for calculating the angle ?. These two magnetic field sensors belong to different measuring axes, and the values of the output signals thereof are less than those of the output signals of the magnetic field sensors belonging to the other measuring axes.

Abstract: Manufacture of a speed sensor, including a cable (15) containing electrical wires for connection between the sensor and a data processing unit, pins joined to the wires and to connection blades of a member for detecting the rotation speed of the wheel of the vehicle, a first molded plastic casing portion (3), having a shaft (13) molded around one end of the wires of the cable, and a cavity in which the pins and the detection member are placed, the pins being mutually separated and the wires being mutually separated at the point of their stripped end, and the detection member being held in place in the cavity of the first casing portion by retaining lugs made of one piece with this first casing portion, and a second casing portion (5) including a part that isolates the pins and the detection member from the outside.

Abstract: Earth formations are characterized by using an array of electrodes which can measure streaming potentials in the formation, and by interpreting the data obtained by the electrodes. The electrodes are placed on a wireline tool, a LWD tool, or in a fixed manner about a completed wellbore. The measured streaming potentials are generated by drilling with an overbearing pressure, slitting the mudcake in a borehole, acid injection, or any of various other manners which causes fluid movement. The data obtained is interpreted to locate fractures, measure formation permeability, estimate formation pressure, monitor drilling fluid loss, detect abnormal pressure, etc. Particularly, a streaming potential voltage transient having a double peak profile signifies the presence of a formation fracture.

Abstract: A method for fabricating and testing an article having a thermal-spray coating thereon. The method includes providing a substrate article having a surface, thermally spraying a coating material onto the surface of the substrate article, wherein a surface of contact between the coating material and the substrate article is a bondline, and nondestructively testing the coated article. Nondestructively testing includes generating an eddy current in the coated article, measuring the eddy current in the coated article, and evaluating a near-bondline region of the coated article located adjacent to the bondline using the measured eddy current.