Abstract: An electromagnetic survey sensing device includes at least two electrodes disposed at spaced apart locations. An electrical to optical converter is electrically coupled to the at least two electrodes. The converter is configured to change a property of light from a source in response to voltage imparted across the at least two electrodes. The device includes an optical fiber optically coupled to an output of the electrical to optical converter, the optical fiber in optical communication with a detector.

Abstract: The present invention is a double-suspension receiver coil apparatus and system for conducting electromagnetic surveys including, both ground-based and airborne measurements. The present invention includes at least one receiver coil suspended by way of first suspension members within an inner frame and said inner frame being suspended by second suspension members within an inner ring which is further enclosed within an outer frame. The double-suspension receiver coil apparatus functions so as to maintain the receiver coil position while minimizing vibrations in order to achieve a high signal-to-noise ratio and enable accurate measurements. The receiver coil may be in an airborne system in a near-horizontal position or in a ground system in a vertical position.

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 device for providing displacement information includes a housing holding a displacement sensor. The displacement sensor includes a coil and a captive core. An electrical measurement of the coil provides information about displacement of the core. The coil has an axis extending in a first direction, wherein the housing has a minimum outside dimension that is less than 3.00 mm when measured perpendicular to that first direction. The housing has an inner surface having a housing inside dimension. The housing is for holding a displacement sensor and a guidance mechanism. The displacement sensor includes a coil and a captive core having a core outside dimension. The guidance mechanism includes a first part and a second part for guiding the core. The first part includes a bearing connected to the housing. The bearing has an axial hole having a hole dimension about equal to the core outside dimension. The core slidably extends through this axial hole.

Abstract: A magnetic field sensing element includes a pair of electrodes; a dielectric polymer layer separating the electrodes; and a network of magnetic nanoparticles in the insulating layer forming a current flow path between the electrodes; where the network of magnetic nanoparticles includes_at least one magnetic tunnel junction involving two neighbouring nanoparticles of different coercivity.

Abstract: Methods and apparatus for determining a presence of a non-conductive coating on electrodes in fluid resistivity measurement devices are described. An example method of determining a presence of a non-conductive coating on electrodes of a fluid resistivity measurement device involves obtaining a first electrical potential value associated with a substantially uncoated condition of first and second electrodes of a fluid resistivity measurement device. The example method also involves measuring a second electrical potential value at a location between the first and second electrodes, comparing the first and second electrical potential values, and determining the presence of a non-conductive coating on at least one of the first and second electrodes based on the comparison.

Abstract: According to one embodiment, an electronic device includes a power supply circuit configured to supply, to a battery, a first charge current for a quick charge and a second charge current for a normal charge smaller than the first charge current, the first charge current and the second charge current being generated from a power from the external power supply, and a controller configured to supply the first charge current to the battery to perform a quick charge when a difference value between a first voltage value of the external power supply wherein the power supply circuit supplies a third charge current smaller than the second charge current to the battery and a second voltage value of the external power supply wherein the power supply circuit does not supply the charge current to the battery is smaller than a threshold.

Abstract: In one embodiment, a method for detecting a damaged magnetoresistive sensor includes analyzing readback signals of a plurality of sensors each being positioned over data tracks on a passing magnetic medium; determining whether at least one of the readback signals is out of phase with respect to the other readback signals, and/or whether at least one of the readback signals has a significantly lower amplitude that the other readback signals. Additional methods are also presented.

Abstract: A slide operation device is comprised of a movement guide of a rod-shape, and a moving block that slides on the movement guide for setting an electric parameter as a measurement value in accordance with a movement amount or position of the moving block in a slide direction along the movement guide. The movement guide is composed of a slide bar and a magnetic scale material. The slide bar is formed of a rigid member with strength difficult to be bent, and formed with a groove extending along the slide direction. The magnetic scale material is made from a resin and a magnetic material and filled in the groove. The slide bar is formed with a concave which is deeper than the groove and which extends in a direction perpendicular to the slide direction, and the magnetic scale material is also filled in the concave.

Abstract: A system to perform a marine subterranean survey includes at least one vertical electromagnetic (EM) source and at least one EM receiver to measure a response of a subterranean structure that is responsive to EM signals produced by the vertical EM source. At least one tow cable is used to tow the EM source and EM receiver through a body of water.

Abstract: An electrical power supply system for a satellite with continuously controlled DC-voltage is suitable for recharging batteries without requiring any specific charge module. To this purpose, at least one solar generator section, so-called charge section, is connected directly to a battery output terminal (B). Simultaneously, at least one battery discharge module is dedicated to the control of a residual current that is not used for recharging the batteries. A first regulator is added to the system in order to control said residual current on the basis of a current produced by the charge section and a charge target for the batteries. Optionally, a second regulator may also be added, in order to directly control the current produced by the charge section when equipment that is electrically powered has a low consumption.

Abstract: A portable self-standing electromagnetic (EM) field sensing locator system with attachments for finding and mapping buried objects such as utilities and with intuitive graphical user interface (GUI) displays. Accessories include a ground penetrating radar (GPR) system with a rotating Tx/Rx antenna assembly, a leak detection system, a multi-probe voltage mapping system, a man-portable laser-range finder system with embedded dipole beacon and other detachable accessory sensor systems are accepted for attachment to the locator system for simultaneous operation in cooperation with the basic locator system. The integration of the locator system with one or more additional devices, such as fault-finding, geophones and conductance sensors, facilitates the rapid detection and localization of many different types of buried objects.

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: A logging tool for use in a wellbore having a sensor portion for making measurements. The tool has a sleeve enclosing the sensor portion and made of a material that is transparent to the measurements being made. One or more structural elements having physical characteristics different from the material comprising the sleeve are carried on the sleeve to enhance the mechanical properties of the sleeve.

Abstract: A plurality of layers of flat coils are stacked and connected in series with each other to form a single coil pole, and the coil pole is energized by an A.C. signal. Magnetism-responsive member, provided to be opposed to the coil pole in a non-contact manner, is displaced relative to the coil pole, so that correspondency, to the coil section, of the magnetism-responsive member varies in response to variation in the relative position and thus impedance variation occurs in the coil pole. Position detection signal is provided on the basis of an output signal, responsive to the impedance variation, taken out from the coil pole.

Abstract: A fabrication process and apparatus provide a high-performance magnetic field sensor (200) from two differential sensor configurations (201, 211) which require only two distinct pinning axes (206, 216) which are formed from a single reference layer (60) that is etched into high aspect ratio shapes (62, 63) with their long axes drawn with different orientations so that, upon treating the reference layers with a properly aligned saturating field (90) and then removing the saturating field, the high aspect ratio patterns provide a shape anisotropy that forces the magnetization of each patterned shape (62, 63) to relax along its respective desired axis. Upon heating and cooling, the ferromagnetic film is pinned in the different desired directions.

Abstract: A magnetic angle sensor 100 comprises a bulk substrate; a circular well 101 provided upon the bulk substrate; an even numbered plurality of electrodes 102a-102x spaced at regular intervals in a ring formation over the circular well; and a pair of biasing electrodes for selectively applying a progressive succession of differently directed bias currents 104 to and/or using the said ring of electrodes 102 to provide a succession of Hall potentials indicative of the relative magnitude of successive differently oriented magnetic field components B in the plane of the magnetic angle sensor 100. The sensor 100 operates cyclically and the full progressive succession cycle involves applying and/or using each electrode 102 in the ring at least once for applying a bias current and/or sensing a Hall potential. In such a manner, the full cycle comprises the progressive succession of the axis of measurement of the sensor 100 through a complete rotation within the plane of the sensor.

Abstract: A method of assembling an eddy current probe for use in nondestructive testing of a sample is described. The method includes positioning at least one substantially planar spiral drive coil within the eddy current probe, such that the drive coil is at least one of adjacent to and at least partially within a flexible material. The method further includes coupling at least one unpackaged solid-state magnetic field sensor to the at least one drive coil.

Abstract: A man-portable locator system for locating buried or otherwise inaccessible pipes, conduits, cables, wires and inserted transmitters using detector arrays and stochastic signal processing and similar techniques to analyze and display multiple target objects at differing frequencies in a layered user interface (UI). For example, the locator UI may be adapted to present a target plurality sorted by proximity of target conductor to the locator operator together with other useful information specifying the multiple objects, frequencies and changes in the subterranean landscape by means of a useful combination of graphical, numeric and acoustic representations.

Abstract: This invention is directed to a downhole method and apparatus for simultaneously determining the horizontal resistivity, vertical resistivity, and relative dip angle for anisotropic earth formations. The present invention accomplishes this objective by using an antenna configuration in which a transmitter antenna and a receiver antenna are oriented in non-parallel planes such that the vertical resistivity and the relative dip angle are decoupled. Preferably, either the transmitter or the receiver is mounted in a conventional orientation in a first plane that is normal to the tool axis, and the other antenna is mounted in a second plane that is not parallel to the first plane. Although this invention is primarily intended for MWD or LWD applications, this invention is also applicable to wireline and possibly other applications.