Abstract: Identification of points of interest in a region of the surface of a part, by bringing a surface reference into intimate contact with the region is disclosed. The surface reference includes a thin film sufficiently flexible to conform to the region and tracks made of electrically conductive material. The passage of an eddy current probe over a track delivers a significant signal representative of the track. This representative signal corresponds to a point of interest thus identified in the region. Thus, it possible to optimize the path and the angular position of an eddy current probe scanning a region of a part to be tested.

Abstract: A rotation angle detector is arranged to detect a rotation angle of an object. The rotation angle detector includes a rotor that rotates about a rotation axis according to a rotation of the object, a detecting unit for detecting a rotation of the rotor, a controller for detecting a rotation angle of the rotor based on a detection signal output from the detecting unit, and a case for accommodating the rotor rotatably. The case has at least three elongate holes provided therein. The elongated holes have longitudinal directions extending radially from the rotation axis of the rotor.

Abstract: A locating device, in particular a hand-held locating device, for detecting objects enclosed in a medium, having a housing and at least one sensor system provided in a housing, as well as an opening penetrating the device. The opening in the measuring device and penetrating the device is illuminable by at least one light source provided in the measuring device.

Abstract: A portable electromagnetic metal detector includes a detection head placed at the end of a support stick. The detection head includes a transmitting coil and a receiving coil. The metal detector has, an electronic command and control box making it possible to operate the detection head. An operator headset is provided for allowing the detector to transmit an audio detection signal to the operator. According to the invention, the generation of the transmission signal and the analysis of the received signal are made in the detection head. The detection head, the electronic box and the operator headset furthermore linked two by two by a multipoint wireless communication network. This wireless communication network advantageously makes it possible to provide a detector that does not include any wired links and to implement the detector according to the invention in various configurations including the three elements or not.

Abstract: A method of estimating standoff in a borehole through an earth formation, includes: disposing a sensor including a plurality of return electrodes and at least one transmitter electrode disposed in a concentric arrangement into the borehole; injecting current, I, into the formation by applying at least two frequencies of alternating current (AC) voltage between at least two of the electrodes; measuring impedance, Z, for each of the frequencies; and using a predetermined relationship between impedance, Z, and standoff, estimating the standoff. A system and a computer program product are provided.

Abstract: Systems and methods for determining a directional movement of an object such as a wheeled vehicle. The system includes a magnet having a north pole and a south pole mounted to the object, a single magnetic sensor positioned such that the sensor can individually detect each magnetic pole as the object moves, the sensor configured to produce a first characteristic signal when a north pole is detected and a second characteristic signal when a south pole is detected, and a processing device in signal communication with the sensor, the processing device configured to determine a directional movement of the object based on a configuration of a signal doublet that includes the first and second characteristic signals. The methods include sensing the north and south poles as they pass the magnetic sensor and determining a direction based on an order in which the north and south poles are sensed.

Abstract: A magneto-sensitive integrated circuit which amplifies a magneto-sensitive output voltage of a Hall element by an amplifier to generate an amplified voltage, converts an output voltage of the amplifier into a digital signal by an A/D converter; and generates a reference voltage of magnitude corresponding to an indicated value. The amplifier includes a voltage superposition element which superposes a DC voltage corresponding to the reference voltage on the amplified voltage to generate the output voltage of the amplifier.

Abstract: A microelectromechanical modulating magnetic device comprising: a base; a magnetic transducer that provides an output in response to a magnetic field associated with the base; at least one movable flux concentrator positioned to move relative to the magnetic transducer; at least one flux collector positioned to collect flux for transfer onto at least one movable flux concentrator; which transfers the magnetic flux to the magnetic transducer for detection and measurement purposes; support structure for enabling the at least one movable flux concentrators to move within a predetermined frequency range; a power source for causing the movable flux concentrators to move at a frequency within the predetermined frequency range; whereby magnetic flux may enter through the flux collector, pass through the at least one movable flux concentrator for transfer to the magnetic transducer, and due to the movement of the movable flux concentrator, the signal outputted from the transducer is modulated.

Abstract: Magnetic field sensors have a magnetic field sensing element and also a feedback circuit to provide a gain-adjustment signal to affect a sensitivity associated with the magnetic field sensing element. In some arrangements, the feedback circuit can include piezoresistors to sense a strain of a substrate over which the magnetic field sensor is disposed. With these arrangements, the feedback circuit can generate the gain-adjustment signal in accordance with the sensed strain. In other arrangements, the feedback circuit can generate pulsed magnetic fields proximate to the magnetic field sensing element in order to directly measure the sensitivity of the magnetic field sensing element. With these arrangements, the feedback circuit can generate the gain-adjustment signal in accordance with the sensed sensitivity.

Abstract: A combined electromagnetic and magnetometer detection system for detecting objects. The system includes a primary electromagnetic transmitter for generating a primary magnetic field; an electromagnetic sensor for sensing secondary magnetic fields generated by a target region subjected to the primary magnetic field; a magnetometer sensor substantially centered at a center of the primary magnetic field; a compensation transmitter for generating a compensating magnetic field that substantially negates the primary magnetic field across the magnetometer sensor; and a signal generator electrically connected to the primary electromagnetic transmitter and the compensation transmitter for driving the transmitters to generate the primary magnetic field and the compensating magnetic field, respectively.

Abstract: A sensor device comprising a base substrate and first and second flux concentrator fixedly attached to the base substrate. The first flux concentrator and the second flux concentrator are positioned with their proximal end regions facing and spaced apart, defining a gap therebetween. A magnetic sensor element is positioned in the gap, the sensor element moveable towards and away from the base substrate. The sensor device has a first system to offset stray magnetic fields, a second system to modulate the sensor element to detect KHz frequency, and a third system to dither noise from the first and second flux concentrators.

Abstract: A microelectromechanical modulating magnetic sensor comprising a base; a magnetic transducer associated with the base that provides an output in response to a magnetic field; a pair of movable flux concentrators positioned to move relative to the magnetic transducer; the pair of movable flux concentrators having a region of high flux concentration between the pair of movable flux concentrators; the pair of flux concentrators moving together in tandem with the distance between the pair remaining substantially constant during movement; support structure for supporting the pair of movable flux concentrators; a power source for causing the movable flux concentrators to move at a frequency within a predetermined frequency range; whereby when the pair of movable flux concentrators is in a first position the region of high flux concentration is in a first location, and when the pair of movable flux concentrators is in a second position, the region of high flux concentration is in a second position; such that as the

Abstract: A variable reluctance analog position device designed to determine the position variation of a target made from a ferromagnetic material. The device includes at least one magnet, the target and the magnet defining a gap therebetween. A magnetosensitive element detects induction variation produced in the gap by relative movement of the target relative to the magnet. The magnet is magnetized in a direction essentially perpendicular to the front surface of the magnet, which defines one edge of the gap. The magnet includes a cavity open at the front surface thereof and the magnetosensitive element is housed in the cavity. Moreover, the target is provided with a specific geometric configuration determined such that the induction variation according to the position of the target corresponds to a pre-defined function.

Abstract: An eddy current probe adapted for detecting cracks in material directly beneath a raised-head fastener is disclosed. The probe comprises an eddy current coil and a support for carrying the coil in an orientation suitable for introducing eddy currents into material directly beneath a raised-head fastener.

Abstract: An electromagnetic impedance sensor detects an object made of conducting material or soft magnetic material with contact-free. The sensor includes: a detection coil; and a detection circuit for supplying electricity to the coil and for measuring electromagnetic impedance change in the coil. The detection coil includes multiple coil portions provided by one wire. One coil portion has a side adjacent to a corresponding side of another coil portion. The side and the corresponding side extend along with a direction, and the side has a current flowing direction, which is the same as the corresponding side.

Abstract: Oil-based mud imaging systems and methods that measure formation permittivity. In some embodiments, disclosed logging systems include a logging tool in communication with surface computing facilities. The logging tool is provided with a sensor array having at least two voltage electrodes positioned between at least two current electrodes that create an electric field in a borehole wall, and is further provided with electronics coupled to the voltage electrodes to determine a differential voltage magnitude and phase. From the magnitude and phase, formation resistivity and permittivity measurements can be determined and used to construct a borehole wall image.

Abstract: A survey technique for use in a marine environment to survey a subterranean structure includes providing an arrangement of plural signal sources in a body of water to produce corresponding signals. The signals of the signal sources in the arrangement are set to cause reduction of at least one predetermined signal component in data received by a receiver in response to the signals.

Abstract: An eddy current testing method for a turbine rotor including a disc, a plurality of turbine blades disposed along the periphery of the disc, and a plurality of pins for joining a blade fork portion formed on each of the plurality of turbine blades to a disc fork portion formed on the disc, the method including inserting a probe having an eddy current testing sensor into a hole formed through the disc fork portion and the blade fork portion by pulling out one of the plurality of pins in a state that the blade fork portion is still inserted into the disc fork portion; and performing eddy current testing for at least part of an internal surface of the hole by using the probe.

Abstract: First and second MR elements are provided with a plurality of element patterns each having a stacked structure. The stacked structure includes a free layer changing its magnetization direction depending on an external magnetic field, an intermediate layer generating no specific magnetization direction, and a pinned layer having magnetization pinned in a certain direction. The first and the second MR elements have a rotationally symmetrical relationship with each other around a central axis parallel to the directions of anisotropic magnetic fields of the free layer. In the initial condition, the resistance of the first MR element and the resistance of the second MR element are equal to each other. The resistances of the first and the second MR elements exhibit changes in opposite directions in accordance with a magnetic field to be detected. This provides a magnetic sensor permitting higher-precision detection of the magnetic field to be detected.

Abstract: An airborne time domain electromagnetic surveying system is provided. The system includes a tow assembly with a flexible support frame. The flexible support frame spaced apart from the aircraft includes a transmitter section with a transmitter loop and a receiver section with a sensor aligned with the central axis of the transmitter section. The flexible support frame has a lightweight modular structure that enables the surface area of the transmitter section to be increased and decreased to suit particular survey applications. The transmitter loop sends a pulse in an “ON” interval, and in an “OFF” interval the sensor measures the earth response to the pulse. The tow assembly also includes a sensor for generating selected survey data in the “ON” interval. A transmitter driver enables the creation of earthbound pulse. The system components are linked to a computer and control computer program linked thereto for controlling the functions thereof.