Abstract: A method of security screening and inspection of people in airlines, ships, or secured buildings, involves placing an array of transmitters and receivers in operational association with the medium. The transmitters generate a broad band harmonic (frequency domain) or pulse (time domain) primary electromagnetic field (EM) field, including the lower frequency portions of the EM spectrum, whose propagation is typically characterized by the diffusion phenomena, or by the combination of the diffusion and wave phenomena. The primary field propagates through and interacts with the examined person and any objects carried by the person to produce a scattered field, which is recorded by the receivers. The scattered EM field components measured by the receivers are applied as an artificial EM field to generate a backscattering EM field.

Abstract: The invention relates to the calibration of the magnetic sensor device comprising magnetic excitation wires (11, 13) and a magnetic sensor element, for example a GMR sensor (12), for measuring reaction fields (B2) generated by magnetic particles (2) in reaction to an excitation field (B1) generated by the excitation wires. The magnetic sensor element (12) can be calibrated by saturating the magnetic particles (2) with a magnetic calibration field (B3). Thus the direct (crosstalk) action of the excitation field (B1) on the magnetic sensor element (12) can be determined without disturbing contributions of the magnetic particles (2).

Abstract: A human-portable utility locator system for locating and tracing a buried utility line characterized by an electromagnetic field emission. The locator may include a horizontal spaced sensor pair for detecting the horizontal field asymmetry of the emitted field in one or more independent frequency bands, which is employed to assist in determining an accurate “virtual depth” measurement for producing detection events. An event detector may be disposed to detect events corresponding to extremum in the B-field gradient with respect to time and a user interface (UI) coupled to the event detector signals the detected event to a user. In a preferred embodiment, one pair of spaced-apart 3D magnetic sensor arrays is disposed substantially orthogonal to another intermediate spaced-apart pair of sensors.

Abstract: A rotating head for a device for the nondestructive testing of metallic test specimens has probe carriers, stray flux or eddy current sensors, a coupling ring and elastic coupling elements. In this way, tandem-like, roughly forced coupling of the pivoting motions of the probe carriers is produced.

Abstract: An apparatus for the nondestructive measurement of materials that includes at least two layers of electrical conductors. Within each layer, a meandering primary winding is used to create a magnetic field for interrogating a test material while sense elements or conducting loops within each meander provide a directional measurement of the test material condition. In successive layers extended portions of the meanders are rotated so that the sense elements provide material condition in different orientations without requiring movement of the test circuit or apparatus. In a bidirectional implementation the angle is 90° while in a quadridirectional implementation the relative angles are ?45, 0, 45, and 90°. Multidirectional permeability measurements are used to assess the stress or torque on a component. These measurements are combined in a manner that removes temperature effects and hysteresis on the property measurements.

Abstract: A system for use when measuring a magnetostriction value of a magnetoresistive element according to one embodiment includes a mechanism for applying a first magnetic field about parallel to a substrate having one or more magnetoresistive elements, and for applying a second magnetic field about perpendicular to the substrate and about parallel to magnetoresistive layers of the elements; a mechanism for applying a mechanical stress to the substrate during application of the magnetic fields; and a measuring subsystem for measuring a signal from at least one of the magnetoresistive elements, wherein the second magnetic field is a magnetic alternating field, wherein the measuring subsystem is locked to a frequency of the alternating field.

Abstract: In a magnetic particle imaging apparatus that forms an image of a distribution of magnetic particles based on changes in a magnetic flux generated by magnetization of the magnetic particles, modulation coils that magnetize magnetic particles present in a field free area by applying a modulation magnetic field to the field free area, and detection coils are disposed such as to suppress an influence caused by a magnetic flux of the modulation magnetic field applied by the modulation coils and included in a detected magnetic flux.

Abstract: A system for use when measuring a magnetostriction value of a magnetoresistive element according to one embodiment includes a mechanism for applying a first magnetic field about parallel to a substrate having one or more magnetoresistive elements, and for applying a second magnetic field about perpendicular to the substrate and about parallel to magnetoresistive layers of the elements; and a mechanism for applying a mechanical stress to the substrate during application of the magnetic fields.

Abstract: Disclosed is a method for quantitatively determining the width of a soft zone area of a partially hardened metallic workpiece, which has at least one hardened and one unhardened area, by means of at least one multifrequency eddy current sensor. A single workpiece being individually is moved relative to the multifrequency eddy current sensor in such a manner that a spatially delimited eddy current field generated by the multifrequency eddy current interacts with the workpiece contactlessly, generates eddy currents therein which, in turn, generate a measuring signal in the multifrequency eddy current sensor, in which the spatially delimited eddy current field has a greatest extension oriented in longitudinal direction to the surface of the workpiece which extension is greater than the maximum extension of the soft zone area in longitudinal direction of the surface of the workpiece.

Abstract: A method for measuring a magnetostriction value of a magnetoresistive element according to one embodiment includes placing a substrate carrying one or more magnetoresistive elements on a fixture; applying a first magnetic field about parallel to the substrate; applying a second magnetic field about perpendicular to the substrate and about parallel to magnetoresistive layers of the one or more elements; measuring a signal from at least one of the one or more elements; applying a mechanical stress to the substrate; and monitoring the signal from the at least one of the one or more elements while changing the first magnetic field.

Abstract: A set of magnets, e.g., electromagnets, are used to produce an in-plane magnetic field with respect to an article under test or manufacture. The set of electromagnets includes electromagnets that are positioned above and below the plane of symmetry respectively. The bottom electromagnets may be positioned below the surface of the chuck for example. The plane of the article and/or set of electromagnets are positioned so that the plane of symmetry approximately coincides with the article. The set of electromagnets may include individual electromagnets or C-core electromagnets, which may produce magnetic fields with complementary polarities near the field of symmetry both above and below the field of symmetry. Magnetic fields with the same polarity are positioned near each other on opposite sides of the plane of symmetry to produce the in-plane magnetic field. A second set of electromagnets may be used to provide field rotation if desired.

Abstract: The present invention provides systems and methods which can be employed to locate or detect presence of various materials, including nonferrous metals. These systems include new and useful sensors, circuits, systems and devices which power and/or interoperate with the sensors, and methods of making, operating and using such systems. Any or all of the systems, devices or processes can be combined with other systems, devices or processes disclosed.

Abstract: An RFEC excitation unit and sensor apparatus and method that facilitate detection of cracks or other anomalies within or under a surface and immediately next to an expected structure (such as a rivet) that would otherwise cause a signal change preventing detection of the cracks. In some embodiments, the apparatus includes actuators and control that move the apparatus and analyze sensed RFEC signals to determine the location of the rivet, and then to rotate (mechanically or electronically) the sensed signal and/or excitation signal to maintain a constant relationship to the edge of the rivet in order that signals from the rivet edge are suppressed and signals from the cracks are detected. In some embodiments, the excitation unit is maintained at the center of the rivet surface, and the sensor is moved around the rivet in a circle centered on the rivet.

Abstract: A recording medium detecting system includes a magnetic field-generating unit that generates an alternating magnetic field in a predetermined particular region, a detecting unit provided close to the particular region, that detects a change in magnetic flux density not smaller than a predetermined magnetic-flux-density difference B2, and a recording medium, containing multiple magnetic wires made of a magnetic material and formed in a wire shape having a predetermined length, that causes a large Barkhausen effect when the alternating magnetic field is applied. A magnetic-flux-density difference B1 detected by the detecting unit at an installation position thereof when the recording medium is placed in the particular region is not smaller than the magnetic-flux-density difference B2.

Abstract: A system for directly measuring a magnetostriction value of a magnetoresistive element includes a fixture for receiving a substrate carrying one or more magnetoresistive elements. A magnet assembly applies a first magnetic field parallel to the substrate, and a magnetic alternating field perpendicular to the substrate and parallel to magnetoresistive layers of the elements. A stress-inducing mechanism applies a mechanical stress to the substrate, the stress being oriented parallel to the substrate. A measuring subsystem measures a signal from at least one of the magnetoresistive elements.

Abstract: A magnetic sensor for determining the position of a cellular phone in linear movement along an axis of translation, the sensor including a measuring cell fitted to a magnetic circuit and capable of measuring the variations in the value of the magnetic induction flux consecutive with the reluctance variations of the magnetic circuit. According to the invention, the sensor further includes a single delimiting fixed magnetic circuit between two fixed pole parts, a variable air gap within which at least a magnetic induction is created that extends along a length parallel to the axis of translation and at least equal to the travel to be measured of the cellular phone, and a measurable air gap to which the measuring cell is fitted.

Abstract: This publication discloses a method and arrangement for determining the hardening depth of steel or other ferromagnetic substances without breaking the object being measured. According to the invention, a varying magnetic field, which causes magnetic Barkhausen noise (MBN), is created in the measurement object with the aid of a magnetization coil 13. The varying magnetic field is regulated in such a way that the maximum force of the magnetic field does not exceed the coercitive force of the unhardened part of the measurement object. The MBN caused is measured with the aid of an MBN sensor. The measured signal is filtered and Fourier transformed. The signal in the frequency range is integrated over a suitable frequency band, in order to determine the value depicting the energy of the MBN. This value correlates with the hardening depth and on the basis of this value it is thus possible to determine the hardening depth.

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: A apparatus for pipeline integrity monitoring comprising a magnetically permeable backing bar and at least three magnets comprising a relatively medium-strength magnet positioned at one end of the backing bar, a relatively low-strength magnet positioned at the other end of the backing bar, and a relative high-strength magnet positioned between the medium-strength and the low-strength magnet. The at least three magnets are adapted and positioned to induce a plurality of resultant fields within the pipeline wall comprising a first resultant field suitable for detecting a reduced metal-related anomaly and a second resultant field suitable for detecting a mechanically worked-related anomaly. Preferably, the first resultant field has a strength greater than 120 Oersted and the second resultant field has a strength between 40 and 80 Oersted.

Abstract: A pair of cores are arranged such that first end portions thereof face to each other with a gap via a conveying path through which a medium to be detected passes. Coils wound at the first end portions of the cores, respectively, are connected in series to each other, thereby constituting a first coil. Coils wound at second end portions on a side opposite to the first end portions are connected in series to each other, thereby constituting a second coil. There are provided an exciting coil which generates a detection magnetic field passing the cores and the gap, and a convergent magnetic field generating unit which generates, in the gap, a convergent magnetic field for converging the detection magnetic field in a direction perpendicular to a direction in which the first end portions of the cores are connected to each other.

Abstract: The present invention provides systems and methods which can be employed to locate or detect presence of various materials, including nonferrous metals. These systems include new and useful sensors, circuits, systems and devices which power and/or interoperate with the sensors, and methods of making, operating and using such systems. Any or all of the systems, devices or processes can be combined with other systems, devices or processes disclosed.

Abstract: An eddy current sensor and a method for detecting the thickness of a film formed on a substrate. The eddy current sensor, which is capable of stable operation, is operable to accurately detect a polishing endpoint. The eddy current sensor detects the thickness of a conductive film from a change in an eddy current loss generated in the conductive film. The eddy current sensor comprises a sensor coil for generating an eddy current in the conductive film, and an active element unit connected to the sensor coil for oscillating a variable frequency corresponding to the eddy current loss. The sensor coil and active element unit are integrated to form the eddy current sensor. Alternatively, the eddy current sensor comprises a sensor coil for generating an eddy current in the conductive film, and a detector for detecting a change in the thickness of the conductive film from a change in a resistance component in an impedance formed by the sensor coil and conductive film.

Abstract: A conveyor has a metal detecting device for detecting metal parts in a conveying product, a magnet arrangement for producing a measuring magnetic field through which the conveying product is movable, a sensor device for registration a change of the measuring magnetic field, a signal evaluating device for evaluating a signal outputted by the sensor device in case of a magnetic field change, to recognize a metal part in the conveying product, and an interference sensor device which in case of a registration of an interference event, which leads to a magnetic field change caused not by metal parts in the conveying product and registered by the sensing device, outputs a faulty triggering warning signal.

Abstract: An apparatus for inspecting a metallic post contoured in a single dimension for defects. The apparatus has a clamp having at least one jaw with a surface conforming to the contour to the metallic post. The conforming jaw or jaws also have a plurality of eddy current coils and the probe has at least one sensor configured to sense at least one of position or motion.

Abstract: A pair of cores is arranged so that their respective first end portions are opposed to each other across a given gap with a transfer path (M) for the passage of a medium between them. Coils wound individually on the respective first end portions of the cores are connected in series with each other to form a first coil. Coils 5a and 5b wound individually on second end portions of the cores are connected in series with each other to form a second coil. Coils wound individually on respective intermediate portions of the cores are connected in series with each other to form a third coil. A signal processing circuit is provided for AC-energizing the third coil to process a detection signal from the first coil and a detection signal from the second coil.

Abstract: A sensor that characterizes welds in materials. The sensor includes a meandering drive winding with at least three extended portions and at least one sensing element placed between an adjacent pair of extended portions. A time varying electric current is passed through the extended portions to form a magnetic field. The sensor is placed in proximity to the test material and translated over the weld region. An electrical property of the weld region is measured for each sensing element location. The weld quality is determined using a feature of the electrical property measurement and location.

Abstract: In an electronic device, a method of measuring an external field and displaying indicia related to the measurement, wherein the electronic device generates a first internal field and at least a second internal field, wherein the method includes the steps of measuring the external field when the electronic device is generating the first internal field; and only displaying indicia related to measurements taken while the electronic device is generating the first internal field. In the preferred embodiment, the first internal field is generated by a rotor of a stepping motor being in a first orientation, and the at least second internal field is generated by the rotor of the stepping motor being in a second orientation, wherein the method includes the steps of determining whether the rotor is in the first orientation before measuring the external field; and if not, causing the rotor to rotate into the first orientation prior to measuring the external field.

Abstract: Magnetic field sensor probes are disclosed which comprise primary or drive windings having a plurality of current carrying segments. The relative magnitude and direction of current in each segment are adjusted so that the resulting interrogating magnetic field follows a desired spatial distribution. By changing the current in each segment, more than one spatial distribution for the magnetic field can be imposed within the same sensor footprint. Example envelopes for the current distributions approximate a sinusoid in Cartesian coordinates or a first-order Bessel function in polar coordinates. One or more sensing elements are used to determine the response of a test material to the magnetic field. These sense elements can be configured into linear or circumferential arrays.

Abstract: A chemical mechanical polishing apparatus and method can use an eddy current monitoring system and an optical monitoring system. Signals from the monitoring systems can be combined on an output line and extracted by a computer. A thickness of a polishing pad can be calculated. The eddy current monitoring system and optical monitoring system can measure substantially the same location on the substrate.

Abstract: A method for detecting a change in permeability of a magnetostrictive object due to a change in strain. At least one first coil and at least one second coil are obtained and positioned such that magnetic flux lines induced by an electric current in the first coil(s) pass through at least one portion of the object in a direction substantially parallel to the strain direction, such that magnetic flux lines induced by an electric current in the second coil(s) pass through at least one portion of the object in a direction substantially parallel to the strain direction, and such that any electromagnetic interference sensed by the first coil(s) is sensed oppositely by the second coil(s). The total inductance of the positioned first and second coil(s) is measured over time. A change in permeability of the object is detected from a change in the measured total inductance over time.

Abstract: A method and apparatus is disclosed for measuring electrical properties of objects by the transmission of electromagnetic waves through a non-magnetizable material. The disclosure also describes a method of measuring changes in electromagnetic signals as the amplitude and frequency of the electromagnetic waves is varied to determine the thickness of an object.

Abstract: An eddy current probe comprising two solenoid coils wound around a common rectangular wafer base of high permeability material extending beyond the coils at wafer corners with the wafer becoming the solenoid core. Posts also of high permeability material depend from a wafer front at its corners with coils crossing orthogonally on the wafer. The coils are connected to alternating current to produce magnetic fields that have like magnetic poles at wafer corners diagonally opposed across the wafer, the coils switching in phase to alternate the magnetic field between posts at base diagonal corners. With the posts at the wafer base corners, the combined magnetic fields generated from the orthogonal coils conduct through the posts and emanate from post ends. The post ends have a curvature matching that of a material to be tested for better coupling the magnetic field into the material.

Abstract: A method which compensates errors resulting from offset voltages and external magnetic fields when a magnetic sensor is used to measure coating thickness. The method also allows compensation of a temperature dependent change for output voltages of the magnetic sensor.

Abstract: An apparatus and method for inspecting contours formed along a predetermined region of a surface on a workpiece formed of an electrically conductive material using eddy current. A probe includes a longitudinal axis and is moveable along a path of travel with respect to the predetermined region to be inspected on a workpiece. At least two coils are spaced longitudinally from one another and supported by the probe to be electrically excited with a predetermined frequency and amplitude during movement of the probe along the path. Sensors are provided for measuring the excitation voltage of each coil as eddy currents are induced in the electrically conductive material of the workpiece by the coils supported on the probe moving along the path of travel with respect to the workpiece.

Abstract: A cylinder position sensing system includes a cylinder housing which slidably receives a rod or shaft element. The cylinder housing has an end piece which slidably receives the shaft element. A first axial groove is formed in the shaft element, and a first magnet member is mounted in the first groove. A second helical groove is formed in the shaft element and is spaced apart from the first groove. A second magnet member is mounted in the second groove. A magnetic field sensor is mounted in the cylinder housing so that the sensor generates an output signal as a function of a relative distance between the first and second magnet members as the second element moves with respect to the first element. Preferably, the shaft element includes a central cylindrical shaft and a hollow cylindrical sleeve mounted over and receiving the shaft. Preferably, the first and second grooves are formed in an inner surface of the sleeve, and the sleeve and the end piece are formed of nonferrous material.

Abstract: The present invention provides for a metallic surface identifying sensor including: a magnetic pole portion for detection which shifts facing a surface of a magnetic body to be identified having an uneven shape wherein the distance from the surface to be identified changes along with the uneven shape while shifting; a reference magnetic pole portion which is placed across from a reference surface, wherein the distance from the reference surface to the magnetic pole portion is maintained approximately constant regardless of the shifting of the magnetic pole portion for detection in relation with the surface to be identified; magnetizing coils which are separately wound around the magnetic pole portion for detection and the reference magnetic pole portion to generate magnetic fluxes; and detecting coils which are separately wound around the magnetic pole portion for detection and the reference magnetic pole portion to detect the magnetic fluxes wherein the uneven shape of the surface to be identified of the met

Abstract: A system for measuring the magnetostriction coefficient &lgr; of a sample material applied to a substrate element fixed at one end leaving the other end free to be deflected. An external rotating magnetic field of rotation frequency f and intensity Hext is applied to the cantilever substrate element the amplitude Am of the deflection of the free end is measured at each of a plurality of rotation frequency harmonics {fm} by, for example, using a plurality of lock-in amplifiers. The harmonic deflection amplitudes {Am} are combined to determine the magnetostriction coefficient &lgr; of the sample material. At an Hext equal to the sample saturation moment Msat and assuming a 15 Oe sample anisotropy Hk and coupling bias Hp, the error in the saturation magnetostriction coefficient &lgr;S measured according to this invention may be reduced by 80% to 90% over the error seen when using only the second harmonic deflection amplitudes A2.

Abstract: A method for non-contact measurement of dimensions such as thickness or diameter and electrical characteristics of an electrically conductive object (6) based on electromagnetic induction and a time-varying magnetic field. A substantially constant current is supplied to at least one transmitter coil (3) such that an electromagnetic field penetrates the object (6). Current to the transmitter coil (3) is cut off and a voltage induced in at least one receiving coil (8) by at least one decaying magnetic field. The voltage in receiving coil (8) is measured from a first time following decay of a magnetic field in the air (T3) until a time when the field has decayed to zero (T4, T5, T6) and the signal is integrated. A value for a physical dimension of the object (6) is calculated from this integral. The method is accurate, undisturbed by surface contamination or object movement, and applicable to different geometric forms including plate, bar or tube.

Abstract: Inductive sensors measure the near surface properties of conducting magnetic materials. The sensors generally include parallel winding segments to induce a spatially periodic magnetic field in a material under test. The sensors may provide a directionally dependent measure with measurements made in varying orientations of the sensor with respect to the material property variation directions. The sensors may be thin, conformable sensors that can be mounted on a test material and, for example, monitor crack initiation under the sensor. A second sensor may be left in air to provide a reference measurement, or the temperature of the material under test can be varied to verify the response of the individual sensing elements. Sensors can be mounted to materials under test in order to not modify the environment that is causing the stress being monitored.

Abstract: A temperature sensing apparatus including a sensor element made of a magnetically soft material operatively arranged within a first and second time-varying interrogation magnetic field, the first time-varying magnetic field being generated at a frequency higher than that for the second magnetic field. A receiver, remote from the sensor element, is engaged to measure intensity of electromagnetic emissions from the sensor element to identify a relative maximum amplitude value for each of a plurality of higher-order harmonic frequency amplitudes so measured. A unit then determines a value for temperature (or other parameter of interst) using the relative maximum harmonic amplitude values identified. In other aspects of the invention, the focus is on an apparatus and technique for determining a value for of stress condition of a solid analyte and for determining a value for corrosion, using the relative maximum harmonic amplitude values identified.

Abstract: Devices and methods for improved inspections of conducting structures of different shapes. An eddy-current probe includes an excitation coil unit, a magnetic detector within the probe, a signal-conditioning/preamplifier circuit within the probe, and a signal channel. The excitation coil unit is shielded on substantially all sides except an emission face that transmits an alternating magnetic signal to a conducting (e.g., metal) object, such that the metal object modifies the alternating magnetic signal. The magnetic detector within the probe is also shielded on substantially all sides except a reception face, such that the alternating magnetic signal as modified by the metal object is received into the shielded magnetic detector and converted into a first electrical signal. The signal-conditioning/preamplifier circuit within the probe is shielded on substantially all sides and provided with electrical power.

Abstract: An embedded eddy current inspection apparatus includes a substrate having an opening, and a test eddy current coil (“test coil”) affixed to the substrate near the opening. An internally inspected multilayer component structure includes an upper layer, a lower layer, and an eddy current probe embedded between the upper and lower layers. The eddy current probe includes the test coil facing a subject layer selected from the upper and lower layers. A method of inspecting a multilayer component structure includes simultaneously energizing the test coil and a reference eddy current coil (“reference coil”) embedded between the upper and lower layers and facing the subject layer. The reference coil is located in a reference region of the multilayer structure. A test signal from the test coil is compared with a reference signal from the reference coil, to determine whether a flaw is present in the subject layer near the test coil.

Abstract: The invention concerns a method and apparatus for determining the hydride content in an electrically conductive substrate by generating a first electromagnetic alternating field that at least partly penetrates the substrate which in turn produces a second alternating field that reacts with the first field. The first field is set at at least two different frequencies and measurement at the frequencies of the combined alternating field formed by the interaction of the first and second fields determines the hydride content in the substrate.

Abstract: The inductive sensor arrangement for detecting metal objects hidden in a surrounding medium comprises a pair of field coils for generating an alternating magnetic flux by a sequential excitation with an AC-current and a pair of sense coils respectively mounted inside each associated field coil in an orientation to the axes of each of said field coils such that essentially no voltage is induced in said sensor coils in an environment free of a metallic object. If a metallic object comes into the vicinity of the inductive sensor four characteristic voltage value sets are produced by the sense coil pair which become subject of an algorithmic processing for defining a position and distinction criterion in respect to said hidden metallic object. The sensor arrangement has the advantage of a single point measurement resulting in an accurate position discrimination for a hidden metallic object like a rebar in concrete.

Abstract: Apparatus for detecting a metal object comprises a transmitter for generating a pulsed or an alternating magnetic field in the vicinity of the metal object to be detected and a detector for detecting the secondary magnetic field induced in the metal object by the transmitted magnetic field. The detector measures at least three magnetic field gradient components of at least first order of the secondary magnetic field. The apparatus also comprises a processor for determining at least one of the position or the electro-magnetic cross-section or an estimate of the shape of the metal object from the measured magnetic field spatial gradient components. The processor fits the measured components to dipole, multiple dipole, multipole, or extended source models. In a preferred embodiment, the invention may comprise three or more pairs of gradiometric coils, or other sensing means.

Abstract: Detecting the presence of an anomaly in or near an object using a probe comprises: a) selecting a set of points on the near surface which are to be inspected, and selecting a first direction and a second direction; b) selecting a first inspection point from the set; c) positioning the probe at the selected inspection point in the first direction, inducing eddy currents in the object and determining a characteristic value of the electromagnetic field; d) positioning the probe in the second direction at the selected inspection point, inducing eddy currents in the object and determining a characteristic value of the electromagnetic field; e) selecting a next inspection point from the set and repeating steps c) and d) until all inspection points have had their turn; and f) inferring that an anomaly is present at an inspection point if a combination of the characteristic values in the first and second direction deviates significantly from a norm.

Abstract: A method and mechanism for ensuring quality control in printed biological assays is provided. A multi-ejector system having a plurality of individual drop ejectors is loaded with a variety of biofluids. Biofluids include at least a carrier fluid, a biological material to be used in the testing, and markers, such as fluorescent dyes. Data regarding the biofluid loaded in each of the drop ejectors is stored along with an expected signature output of the biofluid. Particularly, the signature output represents signals from individual ones of the fluorescent markers included within the biofluid. Once a biological assay consisting of the biofluid drops has been printed, a scanner capable of detecting the markers scans the biological assay and obtains signature output signals for each of the drops of the biological assay.

Abstract: A proximity sensor has a transducer coil that is part of an oscillator circuit. The oscillating signal varies as a function of the presence or absence of a metallic object adjacent the transducer coil. By analyzing selected characteristics of that oscillating signal, the presence of and object and the distance to the object can be determined. Other analysis techniques enable the sensor to distinguish between ferrous and non-ferrous materials. A mechanism also is provided to automatically configure operation of the proximity to avoid interference from another adjacent proximity sensor.

Abstract: An apparatus for the magnetic inspection of ferrous conduit for signs of wear includes a housing having a first end, a second end and a conduit travel passage extending through the housing from the first end to the second end. At least one coil is positioned within the housing encircling the conduit travel passage. The coil is disposed at an angle to the conduit travel passage so as to create a transverse flux component. Sensor supports are positioned along the conduit travel passage encircled by the coil. At least one sensor array is mounted on the sensor supports. The sensor array is oriented to detect flux patterns which extend transversely relative to the conduit travel passage. A computer is in communication with the sensor array to receive and interpret signals from the sensor array.

Abstract: The present invention provides a leakage flux flaw detecting method in which a ferromagnetic substance such as a steel sheet or coil is magnetized by a plurality of magnetic fields with different intensity and magnetic flux leaking from the ferromagnetic substance having been magnetized is detected by a magnetic sensor, and output signals of the magnetic sensor after the detection of leakage flux are processed so that a signal caused by a flaw in the ferromagnetic substance is highlighted. Since this leakage flux flaw detecting method makes it possible to detect flaws with high accuracy, a scaled or descaled hot rolled steel sheet or coil in which the accurate flaw information such as location, density, size, and the like is known can be provided by applying this method to the manufacturing of hot rolled steel sheet or coil.