Abstract: A method and apparatus for obtaining a resistivity measurement of an earth formation surrounding a borehole in an MWD device uses an electrode for injecting current into the earth formation and an electrode for obtaining a responsive signal from the borehole. The electrodes are located on the drill bit arm or blade. Measured resistivity values are obtained at the location of the drill bit. Measurements can be taken in both oil-based mud and water-based mud environments. Maximum or minimum resistivity can be used to best represent the resistivity of the surrounding formation.

Abstract: A flaw detection device for a steel bar enabling inspection of a high temperature steel bar at a high temperature. A pre-treatment unit 31, detection unit 32, and post-treatment unit 33 are arranged along a running direction of a steel bar 10. The pre-treatment unit and post-treatment unit have the same structure. Direct current coils 312 and 332 are wound around the outside of the sleeves 311 and 331. The steel bar is magnetically saturated by the direct current magnetic field. An eddy current is generated at the surface of the steel bar by an alternating current coil 321 of a detection unit 12. The change in the magnetic field caused by the eddy current is detected by the detection windings 322 and 323. The sleeves are made of nonmagnetic materials, so the strength of the direct current magnetic field becomes flat along the running axis of the steel bar. Even when moving the steel bar at a high speed, the occurrence of noise due to changes in strength of the direct current magnetic field is suppressed.

Abstract: Angular position sensor including: a ferromagnetic ring (3) having an axis (8); a magnetic source (1) disposed substantially centrally with respect to the ring (3) and generating a magnetic field following a magnetic direction (6) that is generally perpendicular to the axis (8) of the ring (3); a Hall-effect cell (2) disposed inside the ring (3) on a radius (7) passing through the center of the ring and perpendicular to the magnetic direction (6) and to the axis (8) of the ring (3), the Hall-effect cell (2) measuring the radial magnetic field; a magnetic flux guide (4) interposed between the magnetic source (1) and the Hall-effect cell (2), the magnetic flux guide being rotatable around the magnetic source following the axis (8) of the ring (3).

Abstract: An instrument pig and method of operation thereof for determining the characteristics of a ferromagnetic pipeline through which it passes, including a pig body, first and second coaxial circumferential, spaced apart magnets of opposed polarities supported to the pig body and providing substantially complete magnetic saturation of an area of the pipeline between the magnets, first instruments between the magnets and arranged to generate signals that are responsive to flux leakage servicing to provide first information as to anomalies in the pipeline interior and/or exterior surfaces, second instruments supported by the pig body between said magnets and arranged to generate signals that are responsive to eddy currents induced in the pipeline interior surface servicing to provide second information as to anomalies in the pipeline interior surface, signal processing circuitry combining the first and second signals and wherein the second instruments are energized only in response to signals generated by said signa

Abstract: Position sensing control of the displacement of a first member relative to a second member particularly in a vehicular environment is aided by having a ratiometric relationship between the voltage supply for the sensor and the measuring/control portion of the apparatus. In an embodiment, the relative position of a rear view mirror to its housing is controlled. To facilitate the return of a mirror to a preferred position, the conversion of sensor voltage output to a current and the storage of the current of one or more preferred positions allows for the repeatable setting of the rear view mirror. Over and under voltage protection of the sensor supply voltage provides for consistent measurement and control characteristics.

Abstract: An inductive bridge circuit using mutual inductances to transform impedances is used for detection of wall-thinning defects in metals. The bridge circuit has a first test coil placed adjacent to a good metal section and a second test coil placed adjacent to a metal to be tested. The bridge circuit compares the inductance in the first coil and inductance in the second test coil to compare wall thinning defects. The apparatus may also include first and second measuring transformers which are connected between the bridge circuit and the test coils where the transformers provide for impedance matching and reduced current requirements in the bridge. The circuit may also include one or more potentiometer circuits connected across the bridge which are used for compensating for imbalance of impedance between the first and second test coils when the coils both have known good metal sections adjacent to them.

Abstract: A rotation detecting device includes a rotating direction determining means for determining a rotating direction of the rotor based on a first signal and a second signal, generating a rotating direction signal based on the first signal and the second signal, and outputting a rotating direction determining signal by switching the rotating direction signal with an external switching signal wherein the pulse signal generating means generates the pulse signal in response to the rotating direction determining signal.

Abstract: A magnetic anomaly sensing system uses triaxial magnetometer (TM) sensors arranged in a three-dimensional array. A processor coupled to the TM sensors generates partial gradient contraction data, and complete gradient tensor data and corresponding complete gradient contraction data. The generated data can be used to align the three-dimensional array with a magnetic target. Once the three-dimensional array is aligned with the magnetic target, the generated data can be used to uniquely determine (i) distance to the magnetic target, (ii) position of the magnetic target relative to the three-dimensional array, and (iii) the magnetic dipole moment of the magnetic target.

Abstract: A bearing provided with a rotation sensor comprises an outer ring, an inner ring and rolling elements, and a magnetic ring is engaged with the inner diametral surface of the outer ring. Thus, a highly reliable bearing provided with a rotation sensor exerting no bad influence on a magnetic sensor can be provided.

Abstract: An apparatus for detecting the presence of metal material in a semiconductor wafer. The apparatus comprises: (i) a current-carrying coil for generating a first magnetic field, wherein the first magnetic field is capable of causing the metal material in the semiconductor wafer to generate an opposing magnetic field; and (ii) a detection circuit for detecting the opposing magnetic field generated by the metal material when the semiconductor wafer is in proximity to the current-carrying coil.

Abstract: A Position Sensor comprises: one or more excitation windings; a signal generator adapted to apply excitation signals to the or each excitation winding; tag means displaceable relative to said excitation windings; one or more sensor windings electromagnetically coupled to said excitation windings such that in response to said excitation signals being applied to said excitation windings, there is generated sensed signal in the or each sensor winding; and a signal processor adapted to process said sensed signals to determine the position of said tag means in any location in the X, Y and Z planes essentially in accordance with phase values or in accordance with phase values and amplitude values.

Abstract: A sensor assembly with a universal sensor module for sensing angular position of a rotatable object is provided. The universal sensor module includes a module housing. The sensor module further includes a rotatable assembly in the module housing configured to define a bore for interchangeably receiving one of the following: the rotatable object, and an interface adaptor for receiving the rotatable object. A bearing device allows rotational movement between a stationary assembly and the rotatable assembly. The sensor assembly is configured to accommodate an array of diverse sensing applications with the universal sensor module.

Abstract: A method and system for detecting a magnetic field utilizing a magnetoresistor of a magnetic sensor is disclosed. A normalized magnetoresistance associated with the magnetoresistor can be calculated such that the magnetoresistor comprises an initial magnetization direction thereof. The magnetic field is generally permitted to exceed an ability of the magnetoresistor to remain pointed in the initial magnetization direction, thereby enabling the magnetoresistor to experience a magnetization reversal thereof. The normalized resistance can be placed into a new state in response to the magnetization reversal thereof, thereby permitting the normalized resistance to be utilized as a switch thereof and allowing the magnetic sensor to detect changes in the magnetic field associated with the magnetoresistor.

Abstract: A giant magneto-resistive effect element includes a lamination layer structure portion (10) in which at least a free layer (4) the magnetization of which is rotated in response to an external magnetic field, a fixed layer (2), an antiferromagnetic layer (1) for fixing the magnetization of the fixed layer (2) and a nonmagnetic layer (3) interposed between the free layer (4) and the fixed layer (2) are laminated one on top of another. A sense current flows to substantially a lamination layer direction of the lamination layer structure portion (10) and the lamination layer structure portion (10) has disposed thereon an electric conduction restricting layer (S) in which very small electric conduction areas are dispersedly formed across a path of said sense current, whereby an element resistance can be increased and the amount of magneto-resistance change can be increased.

Abstract: What is described is a sensor array with at least two sub-bridges, which are coupled together to form at least one Wheatstone bridge and which are equipped, in each of the sub-bridges, with at least two magnetoresistive sensor elements, wherein the sensor elements are sensitive to the magnetic field strength of an applied magnetic field along a measurement direction, and the sub-bridges are designed to deliver a measurement signal as a function of a field component of the magnetic field, designated a measurement field, measured in the measurement direction, wherein, further, in a first of the sub-bridges at least two of the sensor elements exhibit barber pole structures with differing alignments, in a second of the sub-bridges at least two of the sensor elements are designed without barber pole structures, and the measurement signals of the first sub-bridge at least largely coincide with the measurement signals of the second sub-bridge in a specified range of values around a zero point of the magnetic field s

Abstract: A magnetic detector includes a moving body which is multipole-magnetized and which is rotated synchronously with a rotational axis; a magnetic resistance element for detecting a change in magnetic field of the rotating moving body; a processing circuit portion for outputting a signal corresponding to the multipole magnetization of the moving body in accordance with the change in resistance value of the magnetic resistance element due to the change in magnetic field; and a magnet for applying a bias magnetic field to the magnetic resistance element.

Abstract: Non-contact type Hall ICs detecting an rotation angle of a throttle valve, a stator core strengthening a magnetic field around the Hall ICs, a lead frame connecting the Hall ICs to an outside ECU are integrated in a sensor cover by resin molding. Thus, the Hall ICs, the stator core, and the lead frame are accurately positioned in the sensor cover. As a result, the Hall ICs are accurately positioned with respect to a permanent magnet disposed in a shaft side of the throttle valve, thereby improving an accuracy of detecting the rotation angle of the throttle valve.

Abstract: A source table showing a standard relation between a detection object and a detection distance is stored in a memory (4). A CPU (3) receives inputs regarding distances to three measurement points from an input portion (5) and recognizes an amplitude voltage corresponding to the input, as a measured value at the measurement point. Furthermore, the CPU (3) extracts a range which corresponds to a difference between the farthest distance and the shortest distance, in which a ratio between voltages corresponding to measurement points closely resembles a ratio between the actually measured values, from the source table as a usage range, and creates a conversion table by correcting voltages in this extracted range.

Abstract: A method and apparatus for the nondestructive detecting of tension wires in a concrete pole from a single test location without requiring scanning along the length of the pole and without requiring direct contact to the wires. The method and apparatus utilize longitudinal guided waves in tension wires that are generated and detected based on the magnetostrictive sensor principle. The detected signals from broken tension wires and from the ends of concrete pole are analyzed for the number and locations of broken wires.

Abstract: A device for detecting one or more parameters of a rotary member angular displacement, includes: and instrumented roller bearing (1) provided with a non-rotating part including a non-rotating ring (2) and a sensor block (8), a rotating part including a rotating ring (2) and a coding ring (15) mounted opposite the sensor block (8) and at least a row of rolling elements (4); and elements for processing signals transmitted by the sensor block. The sensor block (8) comprises at least two sensing elements (9, 10) co-operating with the single coding ring, signals transmitted independently by each sensing element corresponding to the same parameter of angular displacement, so as to supply to the processing elements a redundant information on the parameter of angular displacement.