Abstract: Systems and methods for three-axis magnetic sensors are provided. In one embodiment, a three-axis magnetic sensor formed on a single substrate comprises: an in-plane two-axis magnetic sensor comprising at least one of either a magnetic-resistance (MR) sensor or a magnetic-inductive (MI) sensor formed on the single substrate; and an out-of-plane magnetic sensor comprising a Hall effect sensor formed on the single substrate. The in-plane two-axis magnetic sensor measures magnetic fields in a first plane parallel to a plane of the substrate, and the out-of-plane magnetic sensor measures magnetic fields along an axis orthogonal to the first plane.

Abstract: Systems and methods for three-axis sensor chip packages are provided. In one embodiment, a directional sensor package comprises: a base; a first sensor die mounted to the base, the first sensor die having a first active sensor circuit and a first plurality of metal pads electrically coupled to the first active sensor circuit; a second sensor die mounted to the base, the second sensor die having a second active sensor circuit located on a first surface, and a second plurality of metal pads electrically coupled to the second active sensor circuit located on a second surface. The second sensor die is positioned such that the second active sensor circuit is oriented orthogonally with respect to the first active sensor circuit region and is perpendicular to the base. The second surface is adjacent to the first surface and angled with respect to a plane of the first surface.

Abstract: In a three-axis magnetic sensor, a plurality of magnetoresistive effect element bars are connected in series by means of bias magnets formed on a flat surface parallel to the flat surface of the substrate to constitute magnetoresistive effect elements. The sensitivity direction of magnetization is a direction perpendicular to the longitudinal direction of each of the magnetoresistive effect element bars. Magnetoresistive effect elements forming X-axis and Y-axis sensors have magnetization directions that are orthogonal to each other. Magnetoresistive effect elements of the Z-axis sensor are formed on a tilted surface substrate in such a way that the magnetization direction is inside the tilted surface. The sensitivity direction of the Z-axis sensor is perpendicular to the longitudinal direction of the magnetoresistive effect element bar.

Abstract: A system for and method of determining and compensating for the effect of a field influencing object on a field sensor, preferably a coil, that is within a navigational domain. The navigational domain contains navigational magnetic energy and disturbing magnetic energy, and the field influencing object produces the disturbing magnetic energy in response to the navigational magnetic energy. The correction system includes a first transmitter for projecting into the navigational domain field energy in a first waveform sufficient to induce a first signal value in the sensing coil. The system also includes a second transmitter for projecting into the navigational domain field energy in a second waveform sufficient to induce a second signal value in the sensing coil. The system further includes a signal processor for receiving the first signal value and for receiving the second signal value to determine the effect of the electrically conductive object on the field sensor.

Abstract: A magnetic sensor according to the invention includes: a detector detecting the intensity of magnetic field; a comparison portion comparing the result of the detection with a set threshold value and outputting an output signal corresponding to the result of the comparison; and a threshold-value adjuster adjusting the threshold value. Thus, inconveniences due to a reverse magnetic field phenomenon or magnetic-field offset phenomenon can be solved as simple as possible.

Abstract: A differential magnetic field sensor that enables operation that is independent of sensor-to-target orientation is presented. The differential magnetic field sensor is provided with at least two differential channels. Each differential channel includes a pair of magnetic field sensing elements and has a respective sensing axis defined by those magnetic field sensing elements. The sensing axes are not aligned with respect to each other. One sensing axis is positioned relative to a reference axis of a target profile to define an orientation angle between the sensing axis and the reference axis. The differential magnetic field sensor includes circuitry to produce differential signals associated with the differential channels and use those differential signals to produce a single differential signal having an amplitude that is independent of the orientation angle.

Abstract: A semiconductor process and apparatus provide a high-performance magnetic field sensor from two differential sensor configurations (201, 211) which require only two distinct pinning axes (206, 216), where each differential sensor (e.g., 201) is formed from a Wheatstone bridge structure with four unshielded MTJ sensors (202-205), each of which includes a magnetic field pulse generator (e.g., 414) for selectively applying a field pulse to stabilize or restore the easy axis magnetization of the sense layers (e.g., 411) to eliminate micromagnetic domain switches during measurements of small magnetic fields.

Abstract: A current sensor arrangement comprises plural sensor elements arranged around a centre point, each of the sensor elements having a plane of zero sensitivity to uniform magnetic fields. A first one (202) of the sensor elements has a first angular separation (X1) relative to the centre point from a second, adjacent sensor element (204) and a second angular separation (X2) relative to the centre point from a third, adjacent sensor element (206). The first angular separation is less than the second angular separation. An intercept (I13) of the planes of the first and third sensor elements is located outside a triangle formed by the centre point and the first and third sensor elements and an intercept (I12) of the planes of the first and second sensor elements is located inside a triangle formed by the centre point and the first and second sensor elements.

Abstract: A method of manufacturing an apparatus 200 comprising forming an integrated magnetometer package 202. Forming an integrated magnetometer package 202 includes forming a movable part 215 from a MEM magnetometer substrate 210, and attaching an integrated circuit 910 to one side 212 of the MEM magnetometer substrate. A spacer structure 410 is formed on an opposite side of the MEM magnetometer substrate such that the moveable part is exposed through an opening 420 in the spacer structure. But the moveable part cannot escape through said opening. A permanent magnet 1010 is mounted through the opening to the movable part.

Abstract: A magnetic sensor array includes a first three-dimensional magnetic sensor secured to a substrate in a central location of the substrate. A number of second three-dimensional magnetic sensors are secured to the substrate at a first distance from the first magnetic sensor. Additionally, a number of one-dimensional magnetic sensors are secured to the substrate at a second distance from the first magnetic sensor greater than the first distance. Additional magnetic sensors of any dimension may also be included. The magnetic field sensitivity of the first and second three-dimensional magnetic sensors may be less than the magnetic field sensitivity of the one-dimensional magnetic sensors. The sensing range of the first and second three-dimensional magnetic sensors may be greater than the sensing range of the one-dimensional magnetic sensors. The magnetic sensor array may also include a processing circuit coupled to the magnetic sensors.

Abstract: A magnetic sensor is constituted using magnetic sensor chips mounted on stages supported by interconnecting members and a frame having leads in a lead frame. Herein, the stages are inclined upon plastic deformation of the interconnecting members. When the frame is held in a metal mold and the stages are pressed, the interconnecting members are elastically deformed, so that the magnetic sensor chips are bonded onto the stages placed substantially in the same plane and are then wired with the leads. Thereafter, the stages are released from pressure, so that the interconnecting members are restored from the elastically deformed states thereof. When the magnetic sensor chips are combined together to realize three sensing directions, it is possible to accurately measure three-dimensional bearings of magnetism, and the magnetic sensor can be reduced in dimensions and manufactured with a reduced cost thereof.

Abstract: There is provided a thin film tri-gate fluxgate for detecting a component of a magnetic field in directions of three axes, the thin film tri-gate fluxgate comprising: two first thin film fluxgates of a bar-type disposed on a plane for detecting horizontal components of the magnetic field in direction of dual axis; and a plurality of second thin film fluxgates for detecting a vertical component of the magnetic field, wherein each of the first thin film fluxgates and the plurality of the second thin film fluxgates comprises a drive coil for applying a power, a pickup coil for detecting a voltage and, a magnetic thin film, and wherein the plurality of the second thin film fluxgates are substantially perpendicular to each of the first thin film fluxgates wherein a length of the magnetic thin film of each of the plurality of the second thin film fluxgates is shorter than that of each of the two first thin film fluxgates, and wherein two end portions of each of the plurality of the second thin film fluxgates is wid

Abstract: A multi-axis magnetic field sensing device combines two magnetoresistive sensors to measure the two orthogonal components X, Y of a magnetic field parallel to a system's plane and a Hall sensor to measure the Z component of the magnetic field substantially perpendicular to the system's plane. The two magnetoresistive sensors may be built together in one single chip and then stacked on top of a CMOS die embedding the Hall sensor and associated electronics for the signal processing management of the three sensors and the system's interface.

Abstract: A method of fabricating a multi-axis sensor is provided. The method includes forming patterns of sacrificial material overlaying a substrate and overlaying a flexible material on the sacrificial material and an anchor-surface of the substrate. The flexible material includes sensor-regions, an anchor-region, and at least one hinge-region. The method further includes forming sensor elements from orientable sensor material overlaying respective sensor-regions of the flexible material; forming at least one respective anchor-hinge in the flexible material along the boundary between the anchor-region and an adjacent sensor region; forming the sensor-regions, the anchor-region, and the at least one hinge-region in the flexible material; training the sensor elements to form respective oriented-sensor elements that are oriented in the same direction; etching the sacrificial material; and etching the substrate at an angle from the anchor-surface.

Abstract: Plural transmitter coils of a magnetic locating system are driven with widely-separated main frequencies. One of the transmitter coils is also driven with a marker frequency close to the main frequency applied to that coil. The receiver determines a phase relationship with the transmitter based on the main and marker frequencies, so that the receiver does not suffer from phase ambiguity. The main and marker frequencies may interfere with one another, and the receiver may correct for such interference based on known characteristics of the signals at the main and marker frequencies.

Abstract: Disclosed is a small-sized two-axis magnetic field sensor having a function to cause a magnetic field canceling an external offset magnetic field. The two-axis magnetic field sensor contains a plane coil disposed on a plane and four sets of magneto-resistance element pairs on a plane parallel to the plane coil. The plane coil includes at least two pairs of parallel conductors, and two magneto-resistance elements cross only a single conductor of the coil. A current for canceling the external offset magnetic field is determined in advance, and while a DC current that causes total magnetic fields of biasing magnetic fields plus a magnetic field for canceling the external offset magnetic field flows through the coil, intermediate potential outputs from the magneto-resistance element pairs are detected to measure a magnetic field direction, such as geo-magnetism.

Abstract: A portable device is used to measure exposure to magnetic fields and/or exposure to changes of magnetic field. The device (10) includes a first sensor (14) for measuring instantaneous magnetic field strength, and a second sensor (15) which is located adjacent to, and orientated in the same direction as, the first sensor for providing an output indicative of the time rate of change of the magnetic field. An integrator (22) integrates the rate of change output from the second sensor (15) over time to derive relative changes in the magnetic field. A processor (20) is connected to the outputs of at least the first sensor and the integrator. The processor selectively provides an indication of field strength from the output of the first sensor if the output is within the normal operating range of the first sensor, or otherwise from the integrator. A memory (24) is connected to the output of the second sensor (15) to store cumulative exposure to changes in the magnetic field.

Abstract: A magnetic anomaly sensing system and method uses at least four triaxial magnetometer (TM) sensors with each of the TM sensors having X,Y,Z magnetic sensing axes. The TM sensors are arranged in a three-dimensional array with respective ones of the X,Y,Z magnetic sensing axes being mutually parallel to one another. The three-dimensional array defines a geometry that forms at least one single-axis gradiometer along each of the X,Y,Z magnetic sensing axes. Information sensed by the TM sensors is to generate scalar magnitudes of a magnetic anomaly field measured at each of the TM sensors, comparisons of the scalar magnitudes to at least one threshold value, distance to a source of the magnetic anomaly field using the scalar magnitudes when the threshold value(s) is exceeded, and a magnetic dipole moment of the source using the distance.

Abstract: A magnetic-sensor controller includes an input section, a perpendicular-bisector calculation section, a storage section, and a setting section. The input section successively inputs a plurality of magnetic data sets successively output from a three-dimensional magnetic sensor. Each magnetic data includes three components. The perpendicular-bisector calculation section calculates, for each pair of two of the magnetic data sets, a perpendicular bisector of two points corresponding to the two magnetic data sets. The storage section stores a plurality of perpendicular bisectors. The setting section statistically approximates, by a single point, a region where the plurality of perpendicular bisectors stored in the storage section meet, and sets an offset of the magnetic data set on the basis of the single point. The magnetic-sensor controller enables accurate setting of an offset even when the magnetic field strength changes.

Abstract: There is provided a signal transfer system that has a driver for outputting a signal, a transmission line for transmitting the signal, an insertion-type attenuator, inserted into the transmission line in series, for largely attenuating the low-frequency signal more than a high-frequency signal and an additional-type attenuator, inserted between the transmission line and a reference potential, for largely attenuating the low-frequency signal more than the high-frequency signal, and that matches composite impedance generated by the driver, the insertion-type attenuator and the additional-type attenuator with impedance of the transmission line.

Abstract: A magnetic detector includes a detecting section having a surface facing a magnetic body which moves and emits a magnetic flux. The detecting section includes plural magnetic sensors for detecting the magnetic flux. The magnetic sensors are arranged in a matrix form having three or more rows and three or more columns arranged along the surface of the detecting section. The magnetic detector provides an input device precisely detecting a moving direction and a moving amount of the magnetic body.

Abstract: A system for and method of determining and compensating for the effect of a field influencing object on a field sensor, preferably a coil, that is within a navigational domain. The system includes a first and second transmitter to create signals. A signal processor is able to process the created signals. The method can include determining interference and/or a correct signal based on the two signals. Also, a shield can be provided to limit transmission of selected fields.

Abstract: Devices disclosed according to various embodiments use one or more arrays of atomic magnetometers to detect biologically derived magnetic fields. The disclosed devices and methods relate to application of utilization of a magnetic sensor with unique properties requiring changes in design, allowing new functions, and requiring alternative analysis methodologies. Various embodiments are also directed to methods for obtaining and processing biological magnetic signals. These methods may take advantage of the unique spatial arrangement of the atomic magnetometers and the capacity sensors to he used in either a scalar or a vector mode. Various embodiments have advantages over current magnetometer arrays for the purpose of detecting biological magnetic fields. Such advantages may include, for example: smaller size, lower power consumption, no necessity for cryogenic cooling, potential wafer-level fabrication, and/or the potential of better localization biological signals.

Abstract: A magnetic sensor according to the invention includes: a detector detecting the intensity of magnetic field; a comparison portion comparing the result of the detection with a set threshold value and outputting an output signal corresponding to the result of the comparison; and a threshold-value adjuster adjusting the threshold value. Thus, inconveniences due to a reverse magnetic field phenomenon or magnetic-field offset phenomenon can be solved as simple as possible.

Abstract: A three-axis fluxgate-type circuit having three fluxgate sensors for outputting three analog voltage values respectively. A controller normalizes three digital voltage values corresponding to said three analog voltage values, select a set of linear voltage values from the three normalized digital voltage values and calculate an azimuth based on the set of linear voltage values.

Abstract: At least one waveform characteristic of a vehicular sensor waveform is reported in a wireless vehicular sensor network. The vehicular sensor waveform results a vehicle's presence near a wireless vehicular sensor node. The waveform characteristic may be rising edge, falling edge, waveform duration and/or waveform midpoint of vehicular sensor waveform. Report transmission uses at least one wireless physical transport. Transmitting the report may initiate a response across the wireless physical transport, preferably from an access point, an acknowledgement of receiving the report. The transmitted report may be received by an access point in the wireless vehicular sensor network. The wireless vehicular sensor network may create any of a vehicular traffic report, a vehicular parking report, and/or a vehicular speeding report, based upon the received vehicular sensor waveform report.

Abstract: A portable magnetic anomaly sensing system includes a non-magnetic support structure defined by a rigid beam and a rigid frame coupled thereto. Triaxial magnetometer (TM) sensors are rigidly coupled to the frame with one TM sensor being positioned at each vertex of a cubic space. Each TM sensor is positioned such that all respective X,Y,Z magnetic sensing axes are mutually parallel to one another. A data acquisition system is mechanically coupled to the beam such that any magnetic elements of the data acquisition system do not adversely affect accuracy of the TM sensors. The data acquisition system samples the sensed magnetic field data from all TM sensors synchronously with a timing signal. A processor is mechanically coupled to the beam such that any magnetic elements of the processor do not adversely affect accuracy of the TM sensors.

Abstract: A signal detection circuit of a magnetic sensor includes a differential amplifier to which an output voltage of a detecting coil of the magnetic sensor is applied; a comparator to which the output of the differential amplifier is input, the comparator outputting a digital signal having one logical value during a time period between two adjacent spike voltages included in the output voltage; and a counter that counts the number of pulses of a clock in a period when the output of the comparator has one logical value.

Abstract: A magnetic field verifier apparatus includes a magnetic field detection element configured to produce a voltage signal in response to an applied magnetic field wherein the voltage signal corresponds to the strength of the applied magnetic field. A current source coupled to the magnetic field detection element provides a stimulating current for the magnetic field detection element that builds in a ramp-like progression. A microcontroller is in communication with the voltage signal wherein the microcontroller is configured to detect and control the ramping time of the magnetic field detection element and to sense after the ramping time the voltage signal from the magnetic field detection element. The magnetic field verifier apparatus is configurable to sense particular field strengths at various frequencies and store the readings to provide the user with a reliable verification that a particular magnetic field strength has been produced in a particular environment.

Abstract: There is provided a thin film tri-gate fluxgate for detecting a component of a magnetic field in directions of three axes, the thin film tri-gate fluxgate comprising: two first thin film fluxgates of a bar-type disposed on a plane for detecting horizontal components of the magnetic field in direction of dual axis; and a plurality of second thin film fluxgates for detecting a vertical component of the magnetic field, wherein each of the first thin film fluxgates and the plurality of the second thin film fluxgates comprises a drive coil for applying a power, a pickup coil for detecting a voltage and, a magnetic thin film, and wherein the plurality of the second thin film fluxgates are substantially perpendicular to each of the first thin film fluxgates wherein a length of the magnetic thin film of each of the plurality of the second thin film fluxgates is shorter than that of each of the two first thin film fluxgates, and wherein two end portions of each of the plurality of the second thin film fluxgates is wid

Abstract: A disclosed magnetic sensor includes a substrate having a plane surface and multiple sloping surfaces; multiple soft magnetic films each disposed on a different one of the sloping surfaces and magnetized according to strength of a magnetic field; and multiple detecting devices each disposed on the plane surface, including a free layer and a pinned layer and configured to produce a detection output according to magnetization of the free layer and the pinned layer. Each of the soft magnetic films is magnetically coupled with the free layer of a different one of the detecting devices. The pinned layers of the detecting devices have magnetization directions different from each other.

Abstract: On a single chip are formed a plurality of magnetoresistance effect elements provided with pinned layers having fixed magnetization axes in the directions that cross each other. On a substrate 10 are formed magnetic layers that will become two magnetic tunnel effect elements 11, 21 as magnetoresistance effect elements. Magnetic-field-applying magnetic layers made of NiCo are formed to sandwich the magnetic layers in plan view. A magnetic field is applied to the magnetic-field-applying magnetic layers. The magnetic field is removed after the magnetic-field-applying magnetic layers are magnetized in the direction shown by arrow A.

Abstract: A magnetic sensor array includes a first three-dimensional magnetic sensor secured to a substrate in a central location of the substrate. A number of second three-dimensional magnetic sensors are secured to the substrate at a first distance from the first magnetic sensor. Additionally, a number of one-dimensional magnetic sensors are secured to the substrate at a second distance from the first magnetic sensor greater than the first distance. Additional magnetic sensors of any dimension may also be included. The magnetic field sensitivity of the first and second three-dimensional magnetic sensors may be less than the magnetic field sensitivity of the one-dimensional magnetic sensors. The sensing range of the first and second three-dimensional magnetic sensors may be greater than the sensing range of the one-dimensional magnetic sensors. The magnetic sensor array may also include a processing circuit coupled to the magnetic sensors.

Abstract: A detector for locating a sonde is comprised of a plurality of antennas, a corresponding number of signal isolator modules 1 and a geometrical evaluation module. The magnetic signal generated by the sonde has a fundamental frequency and harmonic frequencies. A frequency spectrum analyzer 29 which forms part of the signal isolator module 1 has frequency bins which are aligned with the fundamental frequency and a plurality of harmonic frequencies of the magnetic signal produced by the sonde. The frequency bins follow variations in the frequency of the magnetic signal produced by the sonde which allows the detector to detect the sonde at a separation of up to 30m.

Abstract: A metal object detecting apparatus comprising, a transmitter for generating a primary magnetic field having a resultant magnetic field direction which varies along any substantially linear path through a surveillance volume such that at three locations along said path the resultant magnetic field points in three mutually substantially orthogonal directions; a detector for measuring a secondary magnetic field at a plurality of positions as a function of time due to the presence of a metal object within the surveillance volume as it passes a plurality of measurement points there-through; and a processor for determining from the measured secondary magnetic fields a track through the surveillance volume comprising a plurality of locations of the metal object and a magnetic moment thereof at each location, the processor being adapted in use to derive there-from a magnetic signature that is characteristic of the metal object and independent of the orientation and track of the metal object.

Abstract: A magnetic sensor array includes a first three-dimensional magnetic sensor secured to a substrate in a central location of the substrate. A number of second three-dimensional magnetic sensors are secured to the substrate at a first distance from the first magnetic sensor. Additionally, a number of one-dimensional magnetic sensors are secured to the substrate at a second distance from the first magnetic sensor greater than the first distance. Additional magnetic sensors of any dimension may also be included. The magnetic field sensitivity of the first and second three-dimensional magnetic sensors may be less than the magnetic field sensitivity of the one-dimensional magnetic sensors. The sensing range of the first and second three-dimensional magnetic sensors may be greater than the sensing range of the one-dimensional magnetic sensors. The magnetic sensor array may also include a processing circuit coupled to the magnetic sensors.

Abstract: A multi-axis magnetic or other field sensing device and method of fabricating a multi-axis magnetic or other field sensing device. An example sensing device is a 3-axis sensor package on a substrate with sensors on opposing sides of the substrate. One side of the substrate includes an X-axis sensor and a Y-axis sensor (or alternatively an integrated X-Y-axis sensor) and the opposite side of the substrate includes a Z-axis sensor on at least one sloped surface, the surface sloped with respect to both the first and second surface areas. One surface is mechanically and electrically bonded to a circuit board via conductive bumps. The other surface electrically connects to the circuit board through bonded wires and/or vias formed through the substrate.

Abstract: A biological tissue equivalent phantom unit to be used by the specific absorption rate measuring system for evaluating absorption of electromagnetic wave energy includes a biological tissue equivalent phantom for absorbing an electromagnetic wave. In addition, two or more electro-optical crystals are arranged at two or more measurement points in the biological tissue equivalent phantom. The electro-optical crystals have a dielectric constant that is approximately equal to that of the biological tissue equivalent phantom. Two or more optical fibers are laid in the biological tissue equivalent phantom for optically connecting each of the electro-optical crystals to an external destination.

Abstract: A 3-axis sensor package with on-board sensor support chip on a single chip. In one aspect of the invention, a sensor package includes an X-axis sensor circuit component, a Y-axis sensor circuit component, or alternatively a combined X/Y-axis sensor circuit component, and a Z-axis sensor circuit component, each mounted to a top surface of a rigid substrate, or alternatively to a printed circuit board (PCB). The pads may be arranged in variety of designs, including a leadless chip carrier (LCC) design and a ball grid array (BGA) design. An application-specific integrated circuit (ASIC), or sensor support chip, is additionally mounted to the top surface of the rigid substrate. The sensor components and ASIC may be ball bonded or wire bonded to the substrate.

Abstract: A method for interpreting the current distribution of an object being measured using basis vector components calculated from the measured signals. The components in question have been so selected that they describe the features, as independent as possible, of the current distribution being examined, which enhances the computation and makes it more accurate. This is achieved by converting the measured signals into a more natural form from the standpoint of the current distribution while totally eliminating the signals associated with the external interferences. After the conversion, the source modeling is performed in an optimal manner using the basis vector components of the signal space instead of the actual measurement signals. One substantial feature of the invention is that after the conversion, the source model need not be regularized any more.

Abstract: In the three-axis magnetic sensor of the present invention, a plurality of magnetoresistive effect element bars are connected in series by means of bias magnets to constitute magnetoresistive effect elements, and magnetoresistive effect elements of the X-axis sensor and those of the Y-axis sensor are formed on a flat surface parallel to the flat surface of the substrate. The sensitivity direction of magnetization is a direction vertical to the longitudinal direction of each of the magnetoresistive effect element bars, and magnetoresistive effect elements of the X-axis sensor and those of the Y-axis sensor are formed in such a way that the magnetization directions are orthogonal to each other. Further, magnetoresistive effect elements of the Z-axis sensor are formed on a tilted surface of the projection projected from the flat surface of the substrate in such a way that the magnetization direction is inside the tilted surface.

Abstract: A magnetic sensor is disclosed that has plural axes at the same time, able to be fabricated in a small number of steps. The magnetic sensor includes a substrate; and plural sensor bridge circuits each including a pair of magnetic field detectors and a pair of fixed resistors on the substrate, the pair of the magnetic field detectors and the pair of the fixed resistors being connected to form a bridge circuit, each of the magnetic field detectors being formed of a magneto-resistance effect element, and magnetization directions of the magnetic field detectors intersect with each other in a three-dimensional manner. The substrate has plural inclined surfaces, normal directions of the inclined surfaces intersect with each other in a three-dimensional manner, and the pair of the magnetic field detectors in each of the sensor bridge circuits is arranged on the same inclined surface.

Abstract: Disclosed herein is an ELF or LF magnetic field measuring system, which can easily measure each magnetic field component existing in a free space generated by electric appliances or in a human body phantom filled with a specific fluid. A 3-axes magnetic field probe for use in the magnetic field measuring system comprises resistive lines in a protective sleeve rod electrically connected to the transmission board, an isotropic sensing head having a cubic shape, one end of the protective sleeve rod being rigidly connected to a corner point of the cubic sensing head where three faces coincide, and three bobbins adhered to three adjacent faces which coincide at a corner point diagonally opposite to the first corner point. A coil is wound on the periphery of each of the bobbins. The sensor is moved by an automatic mechanical machine to scan a pre-programmed surface where the magnetic field distribution is to the evaluated.

Abstract: A method and device by means of which an irrotational, sourceless vector field can be expressed by a number of physically reasonable basis vectors. In the method and device for processing a multi-channel measurement of magnetic fields of the present invention, measured signals can be unambiguously divided into signals of the irrotational, sourceless vector field that are caused by an interesting object or external interferences, as well as into a signal caused by the nonideality of the measuring device. The invention is based on the combining of two very fundamental mathematical regularities and applying in the processing of signal vectors of a multi-channel measuring device that measures an irrotational, sourceless vector field. The invention is based on the Maxwell's equations of an irrotational, sourceless vector field, as well as on the convergence characteristics of series developments.

Abstract: A sensor for sensing a magnetic field direction has a plurality of magnetoresistive sensor elements, each of which having a main sensitivity direction with respect to a present magnetic field. Lines associated with the main sensitivity directions of the magnetoresistive sensor elements and passing through the magnetoresistive sensor elements intersect in an area outside the magnetoresistive sensor elements themselves.

Abstract: An attitude detection sensor includes three magnetic sensing parts that detect magnetic field strength in respective directions along three axes perpendicular to each other, and two tilt sensing parts that detect tilt angles around two axes perpendicular to each other. The tilt sensing parts each include a cantilever having a magnet body that moves in accordance with the tilt angle, and a magnetic detection head that detects a displacement of the magnet body. The three magnetic sensing parts and the two magnetic detection heads are each formed using a magnetic detection element of the same type. At least one electronic circuit for controlling the five magnetic detection elements, the three magnetic sensing parts, and the two tilt sensing parts is disposed in a single package in the form of a module.

Abstract: A portable device is used to measure exposure to magnetic fields and/or exposure to changes of magnetic field. The device (10) includes a first sensor (14) for measuring instantaneous magnetic field strength, and a second sensor (15) which is located adjacent to, and orientated in the same direction as, the first sensor for providing an output indicative of the time rate of change of the magnetic field. An integrator (22) integrates the rate of change output from the second sensor (15) over time to derive relative changes in the magnetic field. A processor (20) is connected to the outputs of at least the first sensor and the integrator. The processor selectively provides an indication of field strength from the output of the first sensor if the output is within the normal operating range of the first sensor, or otherwise from the integrator. A memory (24) is connected to the output of the second sensor (15) to store cumulative exposure to changes in the magnetic field.

Abstract: A device (16) used to measure at least one component of a magnetic field, includes a magnetoresistive sensor (102) and a measuring chain (28). The input of the measuring chain is connected to the magnetoresistive sensor (102), while the output thereof is intended to supply information that is representative of the magnetic field in the region of the sensor. In addition, the measuring chain (28) includes elements (136) for isolating a frequency component of the signal from the sensor representative of the magnetic field for a unique pre-determined frequency (FI).

Abstract: A metal detection apparatus includes a transmitter for generating a magnetic field in the vicinity of the metal object, and a detector for detecting a secondary magnetic field. The detector include a first gradiometer for providing a first output signal representative of a first direction, y, to the metal object, a second gradiometer arranged substantially orthogonal to the first gradiometer for providing a second output signal representative of a second direction, x, to the metal object, the second direction being substantially orthogonal to the first direction and in the same plane as the first direction, and an outer coil and an inner coil arranged to be substantially concentric with one another and each of which is arranged to provide an output signal representative of secondary magnetic field strength in a third direction, z, which is substantially orthogonal to the plane of the first and second directions.

Abstract: A method detects relaying of a contactless data communication by a radio amplifier for intercepting and manipulating the communication to achieve an unauthorized authentication. The method involves transmitting an electromagnetic field successively from at least two spatially separated antennas of a transmitting unit, receiving the transmitted fields in a receiving unit, determining field strength vectors of the received fields allocated to each antenna, and comparing actual values of the vectors with prescribed nominal values stored in a nominal value field that maps the true field strength distribution in multi-dimensional space around the transmitting unit. The actual field strength magnitude and the reception angle between the transmitting antennas can be determined from the vectors and compared with stored nominal values in this manner. When the determined actual values match prescribed nominal values of the nominal value field, the occurrence of a relaying of the signal can be reliably excluded.