Abstract: Disclosed is a magnetostrictive transducer for generating and receiving elastic waves in a testing plate and an apparatus for structural diagnosis using the magnetostrictive transducers. More particularly, disclosed is a magnetostrictive transducer which may generate and transmit elastic waves using the magnetostrictive effect in any directions without re-attaching ferromagnetic patch on the non-magnetic testing plate and may produce Lamb waves and Shear Horizontal (SH) waves in desired directions, and an apparatus for structural diagnosis using the magnetostrictive transducers. There is provided a magnetostrictive transducer comprising: a patch made of ferromagnetic material; and a magnetic field generator for generating magnetic field applied to the patch, the magnetic field generator being placed on the patch, wherein the magnetic field generator comprises: a main body; two magnets for generating bias magnetic field, the magnets being apart from each other; and a coil for winding around the magnets.

Abstract: A method and apparatus for implementing magnetostrictive sensor techniques for the nondestructive evaluation of pipes or tubes. A magnetostrictive sensor generates guided waves in a pipe or tube, which waves travel therethrough in a direction parallel to the longitudinal axis of the pipe or tube. This is achieved by using a magnetized ferromagnetic strip being pressed circumferentially against the pipe or tube. For improved efficiency, the strip may be made from an iron-cobalt alloy. The guided waves are generated in the strip and coupled to the pipe or tube and propagate along the length of said pipe or tube. For detection, the guided waves in the pipe or tube are coupled to the thin ferromagnetic strip and are detected by receiving MsS coils. Reflected guided waves may represent defects in the pipe or tube.

Abstract: An eddy current probe and associated method of inspecting a structure are provided that are capable of generating a two-dimensional image of the structure, generally in real time. The eddy current probe includes an eddy current probe array having a plurality of first and second coils that cross one another to define a plurality of sensing elements. The eddy current probe array may also include a plurality of magnetically permeable core elements located coincident with respective sensing elements and at least partially encircled by respective first and second coils. The eddy current probe may also include an alternating current source electrically connected to the first coils and sense electronics for sensing current induced in the second coils. In operation, the current sensed in the second coils represents at least one characteristic of the structure, such as the electrical conductivity of the structure.

Abstract: A pulsed eddy current sensor probe includes a sensor array board. A number of sensors are arranged on the sensor array board and are operable to sense and generate output signals from the transient electromagnetic flux in a part being inspected. Each of the sensors has a differential output with a positive and a negative output. At least one drive coil is disposed adjacent to the sensors and is operable to transmit transient electromagnetic flux into the part. A first and a second multiplexer are arranged on the sensor array board and are operable to switch between the sensors. The first and second multiplexers are connected to the positive and negative outputs of the sensors, respectively.

Abstract: A sensor measurement of an article having an article surface shape is performed using a hand-held senor probe having a probe housing, a sensor support rotatably mounted in the probe housing and having an orienting structure defined thereon. The orienting structure is preferably an orienting face with substantially the article surface shape. A sensor, such as a eddy current sensor, is affixed to the sensor support and is operable through the orienting face of the sensor support. The orienting face of the sensor support is pressed against the article surface to orient the sensor support and thence the sensor relative to the article surface, and the sensor measurement is performed. The sensor is preferably a ball having the orienting face thereon, and mounted to the probe housing in a ball-and-socket relationship.

Abstract: A giant magnetoresistive flux focusing eddy current device effectively detects deep flaws in thick multilayer conductive materials. The probe uses an excitation coil to induce eddy currents in conducting material perpendicularly oriented to the coil's longitudinal axis. A giant magnetoresistive (GMR) sensor, surrounded by the excitation coil, is used to detect generated fields. Between the excitation coil and GMR sensor is a highly permeable flux focusing lens which magnetically separates the GMR sensor and excitation coil and produces high flux density at the outer edge of the GMR sensor. The use of feedback inside the flux focusing lens enables complete cancellation of the leakage fields at the GMR sensor location and biasing of the GMR sensor to a location of high magnetic field sensitivity. In an alternate embodiment, a permanent magnet is positioned adjacent to the GMR sensor to accomplish the biasing.

Abstract: An omnidirectional eddy current probe includes a number of sense coils arranged in a stack having a principal axis. At least two of the sense coils are rotationally skewed about the principal axis relative to one another. The sense coils are operatively connected to each other and a drive coil is also positioned in the stack. An impulse through the drive coil induces a magnetic influx through a conducting material specimen having a surface, thereby generating eddy currents on the surface. Secondary magnetic field generated from the eddy currents produces corresponding signals in the sense coils, and the signals are then analyzed for the possibility of surface flaw in the conducting material.

Abstract: An apparatus for applying a method for managing the integration of multiple pipeline datasets into a combined dataset or superset otherwise known as an asset survey. As each dataset is integrated into the asset survey a data management module is responsible for setting the status field of each feature point dependant on its relative age, source, name and type. The field “status” has five distinct states; active, inactive, archived, super inactive and super active. Active is representative of the latest and most accurate condition of the pipeline. Inactive indicates that the record has either been superseded by better data or the record is from new data and has not yet been validated as accurate. Archived indicates the record is associated with a piece of pipe that was removed from service (i.e. cut out of the pipeline).

Abstract: An eddy current inspection probe provides multiple interchangeable configurations for enabling an inspector to reach most or all portions of most or all turbine blades within a combustion turbine by inserting the probe through an inspection port, without disassembling the turbine. The probe shaft contains the electronic signal wire for the inspection tip and a port for a video probe, thereby facilitating use of the video probe and protecting these components. The inspection tip connector at the end of the main shaft is pivotally secured to the shaft, and may be set at any desired angle by using a semirigid or rigid member passing through the shaft, and connected to lever within the handle. Any one of a plurality of probe tips and shaft extensions may be selected to configure the inspection probe to reach a desired location within the turbine.

Abstract: An electromagnetic counter includes a case, an electromagnet, an anchor rotatable through magnetization and demagnetization of the electromagnet, and number wheels rotated by a predetermined angle according to the rotation of the anchor. A flexible board with a light emitting diode is disposed in a confined space in the case for illuminating the number wheels.

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

Abstract: A 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: A method of inspecting an interconnection pattern formed by depositing a metal onto a substrate having an interconnection pattern groove formed on a surface thereof includes: selectively measuring a thickness of a part above the substrate of a metal film formed on the substrate, the part above the substrate being a part constituted of the metal deposited upward from substantially the same surface as the surface of the substrate on which an interconnection pattern groove is formed; and evaluating how successfully the interconnection pattern groove is filled with the metal on the basis of a film thickness value obtained by the selective measurement.

Abstract: A method for determining the material from which an underground pipe is made. The method exposes a portion of the pipe, applies a coil having a primary winding and a secondary winding to the exposed portion of pipe such that the pipe contributes to an inductive coupling between the primary winding and the secondary winding, applies an excitation current to the primary winding to induce in the secondary winding a signal indicative of an induction value of the pipe, and determines the material from which the pipe is made dependent upon the signal induced in the secondary winding.

Abstract: A method for detecting breaks in a prestressed wire, rod or bar in prestressed concrete pressure pipe (PCCP), embedded in concrete and/or mortar is described. A remote field eddy current exciter/transformer coupling probe is traversed axially internally through the PCPP so as to create an energy flow path within and external to the wall of the PCPP and to induce a transformer coupling from the prestressing winding thus generating a signal in a detector spaced from and usually approximately coplanar with the exciter. As the exciter traverses a break in the wire, rod or bar, a small signal change is generated in the detector, nearly regardless but not independent of the radial position of the detector relative to the break.

Abstract: Discloses methods to perform magnetic testing of tensioning elements in a pre-stressed concrete cylinder, such as a pipe or water reservoir and testing apparatus. The apparatus includes magnetic flux production means and detector means disposed proximal to a surface of the cylinder in a plane in common with the magnetic flux production means that is orthogonal to an axis of the cylinder. The apparatus operates over a range of low frequency signals, for example, between 20 and 300 hertz or a pulse. Output of the inspection apparatus includes a signal and distance plot showing the results of testing a cylinder at one or more frequencies. In accordance with another method of analysis, a characteristic of the phase of the output over distance is plotted, including the phase or representations of the in-phase or quadrature components of the received signal in relation to the driving signal.

Abstract: An exciting coil is constructed by winding a winding in a groove formed on the outer circumference of a circular ring member, and a detecting coil in the shape of a polygon (such as a triangle and a pentagon) when seen from the front is positioned. One side of the detecting coil is placed in a diameter direction of the exciting coil, inside the exciting coil, and the vertex opposite to the one side is placed apart from the exciting coil so that the detecting coil is orthogonal to the exciting coil. A side surface of the exciting coil on the side opposite to the vertex is placed to face the surface of a test material, and used as a flaw detection surface.

Abstract: A process control method is described which uses measurements from magnetic field sensors to monitor the condition of material, such as from a heat treatment process. The sensors can be single element sensors or sensor arrays, can be used to periodically inspect selected locations, mounted to the test material, or scanned over the test material to generate two-dimensional images of the material properties. The sensors can be exposed to the same process conditions as the material, such as elevated temperatures, or the shielding layers can be placed between the test material and the sensors to reduce sensor exposure to the processing conditions. Additional property measurements, such as sensor lift-off, can be used to ensure proper sensors operation.

Abstract: Discloses methods to perform magnetic testing of tensioning elements in a pre-stressed concrete cylinder, such as a pipe or water reservoir and testing apparatus. The apparatus includes magnetic flux production means and detector means disposed proximal to a surface of the cylinder in a plane in common with the magnetic flux production means that is orthogonal to an axis of the cylinder. The apparatus operates over a range of low frequency signals, for example, between 20 and 300 hertz or a pulse. Output of the inspection apparatus includes a signal and distance plot showing the results of testing a cylinder at one or more frequencies. In accordance with another method of analysis, a characteristic of the phase of the output over distance is plotted, including the phase or representations of the in-phase or quadrature components of the received signal in relation to the driving signal.

Abstract: The testing results, etc. of surface flaws such as cracks formed in or just below a surface of a body to be detected are displayed using colors within different color regions in the color space when displaying, on the basis of a preset threshold value, the test signal ranging in magnitude from zero to the threshold value and the test signal falling in magnitude beyond the threshold value while changing the color and/or the depth of color little by little within each of the color regions according to the magnitude of the test signal. This enables small flaw signals, etc. to be displayed without exception, thereby preventing small flaws, etc. from being overlooked.

Abstract: A method for the nondestructive measurement of the thickness of thin layers having a probe, having a first coil device on an inner core, the geometrical center of which coil device and the geometrical center of at least one second coil device coincide, the at least one second coil device partially surrounding the first coil device, and an evaluation unit, to which signals of the coil devices are emitted during a measurement for ascertaining the layer thickness. A circuit is provided, by which the first and the at least one second coil devices are excited sequentially during a measurement.

Abstract: A method of detecting undesired metal objects in a document feed path and a document processing apparatus that includes a feeder for transporting document sheets along a feed path; and a detector for detecting the presence of foreign metal objects in said feed path. The detector comprises a source of alternating electrical energy connected to a conductive transmitter loop for generating a pulsed magnetic field proximate the feed path and a conductive receiver loop that receives reflected magnetic field signals. The reflected magnetic signals induce electrical signals in the receiver loop which are amplified and processed to produce output signals which are sent to a phase shift analyzer which discriminates among output signals produced in the receiver loop by magnetic reflections from metal objects of varying types to provide an output signal when an undesired metal object in the feed path is detected.

Abstract: A coating thickness measuring instrument is provided. The coating thickness measuring instrument has a first mode of operation in which it is operative to make measurements with a first resolution and a second mode of operation in which it is operative to make measurements with a second resolution, the first resolution being greater than the second. The instrument may provide a first short range high resolution mode and a second long range low resolution mode. The first range may be contained in or overlap the second range.

Abstract: A differential probe is scanned along a stator core tooth portion to detect lamination faults. The probe utilizes two magnetic flux injection yokes arranged side-by-side in relatively close proximity, each yoke having two arm portions and two core-tooth flux-injection surfaces, each yoke being wound with an excitation coil winding and at least one yoke-arm of each yoke having a magnetic flux sensor. Current is supplied to the excitation coil windings on each yoke to inject magnetic flux into the stator core laminations while the probe is moved in a scanning process along the core teeth across the laminations. The magnetic flux differential detected at adjacent regions in the core by flux sensors on each of the two yokes is used to incrementally evaluate the core for laminations faults. The output produced by the differential probe may be converted to a digital signal and provided to a computer system for storage and future analysis.

Abstract: A method and apparatus is shown for implementing magnetostrictive sensor techniques for the nondestructive evaluation of pipes or tubes. A magnetostrictive sensor generates guided waves in a pipe or tube, which waves travel therethrough in a direction parallel to the longitudinal axis of the pipe or tube. This is achieved by using a magnetized ferromagnetic strip being pressed circumferentially against the pipe or tube. For improved efficiency, the strip may be made from an iron-cobalt alloy. The guided waves are generated in the strip and coupled to the pipe or tube and propagate along the length of said pipe or tube. For detection, the guided waves in said pipe or tube are coupled to the thin ferromagnetic strip and are detected by receiving MsS coils. Reflected guided waves may represent defects in the pipe or tube.

Abstract: A method of determining a surface profile of an electrically conductive object, using a probe having a transmitter adapted for inducing transient eddy currents in the object, and a receiver which is adapted for providing a signal indicative of a magnetic field property wherein the surface profile is determined by measuring a characteristic value at selected inspection positions at a selected set of inspection points to obtain a set of inspection values, and correcting for any offsets using a calibration function determined from a set of calibration values taken at a set of calibration positions at a calibration point.

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: An exciting coil is constructed by winding a winding in a groove formed on the outer circumference of a circular ring member, and a detecting coil in the shape of a polygon (such as a triangle and a pentagon) when seen from the front is positioned. One side of the detecting coil is placed in a diameter direction of the exciting coil, inside the exciting coil, and the vertex opposite to the one side is placed apart from the exciting coil so that the detecting coil is orthogonal to the exciting coil. A side surface of the exciting coil on the side opposite to the vertex is placed to face the surface of a test material, and used as a flaw detection surface.

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: Described are methods for monitoring of stresses and other material properties. These methods use measurements of effective electrical properties, such as magnetic permeability and electrical conductivity, to infer the state of the test material, such as the stress, temperature, or overload condition. The sensors, which can be single element sensors or sensor arrays, can be used to periodically inspect selected locations, mounted to the test material, or scanned over the test material to generate two-dimensional images of the material properties. Magnetic field or eddy current based inductive and giant magnetoresistive sensors may be used on magnetizable and/or conducting materials, while capacitive sensors can be used for dielectric materials. Methods are also described for the use of state-sensitive layers to determine the state of materials of interest. These methods allow the weight of articles, such as aircraft, to be determined.

Abstract: A method for in-situ eddy current inspection of at least one coated component includes applying a drive pulse at a measurement position on an outer surface of the coated component, while the coated component is installed in an operational environment of the coated component. The coated component includes a base metal and a coating disposed on the base metal. The method further includes receiving a response signal from the coated component, comparing the response signal with a reference signal to obtain a compared signal, analyzing the compared signal for crack detection, and determining whether a crack near the measurement position has penetrated into the base metal, if the presence of the crack in the coating is indicated.

Abstract: Method of detecting cracks in an object of an electrically conducting material that is covered by a non-conductive layer using a probe comprising a transmitter coil for inducing eddy currents in the object and a receiver coil comprising selecting a set of points of the object which are to be inspected; and which method further comprises for each point positioning the probe at the point, activating the transmitter coil to induce eddy currents in the object; creating a record of the signal provided by the receiver coil over a period of time; and examining the record and comparing it to reference records, wherein the presence or absence of a crack can be inferred from the comparison.

Abstract: A gas pipe explorer formed of a plurality of connecting elements, and an articulation element between the connected elements. The connected elements include drive capabilities, and the articulation element allows the connected elements to traverse gas pipes of arbitrary shapes and sizes. A sensor may sends the characteristics of the gas pipe, and the communication element may send back those sends characteristics. The communication can be wired, over a tether connecting the device to a remote end. Alternatively, the connection can be wireless, driven by either a generator or a battery.

Abstract: A display apparatus of magnetic flux density for detecting an internal crack of a metal or a shape of the metal includes a three-dimensional magnetic flux focusing unit installed near the metal, for concentrating magnetic flux generated by the metal, a magnetic flux density measurement unit installed near the magnetic flux focusing unit, for measuring changes in magnetic flux density concentrated by the magnetic flux focusing unit, and a display unit electrically connected with the magnetic flux measurement unit, for real-time displaying and storing changes in the magnetic flux density.

Abstract: Disclosed herein is a method of discriminating a through-wall crack and measuring the through-wall length of the crack in a steam generator tube of a nuclear power plant. The method of the present invention is characterized in that the through-wall crack is discriminated and the through-wall length of the crack is measured in such a way that there are measured the number and positions of inflection points of a graph that is plotted by relating characteristic amplitude values of eddy current signals, which are generated whenever a coil of a motorized rotating probe passes the crack while being spirally rotated, to the positions in the length of the crack.

Abstract: Apparatus and methods are described for the improved throughput and increased reliability for inspection of critical surfaces on aircraft engine disks. Eddy current sensor arrays allow two-dimensional images to be generated for detection of cracks in regions with fretting damage. Background variations due to fretting damage and stress variations are also accommodated. These arrays are combined with instrumentation that permits parallel data acquisition for each sensing element and rapid inspection rates. Inflatable support structures behind the sensor array improve sensor durability and reduce fixturing requirements for the inspection.

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: A method for in-situ eddy current inspection of at least one coated component includes applying a drive pulse at a measurement position on an outer surface of the coated component, while the coated component is installed in an operational environment of the coated component. The coated component includes a base metal and a coating disposed on the base metal. The method further includes receiving a response signal from the coated component, comparing the response signal with a reference signal to obtain a compared signal, analyzing the compared signal for crack detection, and determining whether a crack near the measurement position has penetrated into the base metal, if the presence of the crack in the coating is indicated.

Abstract: This invention relates to the method and apparatus for indicating roller wear in a media handling device. Such structures of this type, generally, employ the use of variable inductance to determine roller wear. The media transport roller has a non-conductive surface with a conductive core. Located just above the conductive core is a rod containing a power coil that is driven by AC excitation and a pick-up coil. The pick-up coil is connected to circuitry that measures the inductance. As the media transport roller wears, the conductive core moves closer to an inductive pick-up unit. The measured output voltage from the pick-up unit depends upon the distance between the core and the pick-up unit. This inductance change can then be correlated to media transport roller wear and relayed to the user through the use of an LED or other similar types of numerical/graphical displays.

Abstract: A method and system for detecting or measuring defects in a rope having ferromagnetic tension members includes a magnetic field exciter and an array of magnetic flux sensors corresponding to the tension members in a known relationship. Measurements of magnetic flux leakage are indicative of defects. Another aspect of the invention includes a method and system for detecting or measuring defects in an elevator rope having electrically conductive tension members, whereby measured electrical resistance in the tension members is indicative of defects.

Abstract: A method and apparatus is shown for implementing magnetostrictive sensor techniques for the nondestructive evaluation of ferromagnetic pipes or tubes. A magnetostrictive sensor generates shear waves and/or torsional waves in ferromagnetic pipes or tubes, which waves travel therethrough in a direction parallel to the longitudinal axis of the pipe. A circumferential magnetization is generated in the ferromagnetic pipe or tube by a DC or low frequency voltage establishing a current along the longitudinal axis and past the magnetostrictive sensor. Reflected shear or torsional waves may represent defects in the pipe or tube.

Abstract: Discloses methods to perform magnetic testing of tensioning elements in a pre-stressed concrete cylinder, such as a pipe or water reservoir and testing apparatus. The apparatus includes magnetic flux production means and detector means disposed proximal to a surface of the cylinder in a plane in common with the magnetic flux production means that is orthogonal to an axis of the cylinder. The apparatus operates over a range of low frequency signals, for example, between 20 and 300 hertz or a pulse. Output of the inspection apparatus includes a signal and distance plot showing the results of testing a cylinder at one or more frequencies. In accordance with another method of analysis, a characteristic of the phase of the output over distance is plotted, including the phase or representations of the in-phase or quadrature components of the received signal in relation to the driving signal.

Abstract: The present invention relates to a device for measuring the value of a parameter relating to an electrically conductive object. Such a parameter can be the electric conductivity or the degree in which the material has changed under the influence of external conditions. Alternatively the parameter is the quality of a weld or the thickness of the object.

Abstract: The present invention relate to a device for the non-destructive evaluation of such structures and components as are in service and which are intended to continue in use for an extended period during which time a number of defects such as residual stress, fatigue, creep or the formation of magnetic phase in non-ferromagnetic steel can develop; in addition to its primary purpose of detecting and/or determining the stated defects in-service steel structures or components, the device of the present invention also possesses the advantage that it can be applied for the sorting and classification of steels of different compositions according to the results of defects detected.

Abstract: This invention relates to apparatus for the nondestructive measurements of materials. New eddy current sensing arrays and methods are described which provide a capability for high resolution imaging of test materials and also a high probabilitity of detection for defects and flaws around features such as fasteners. The arrays incorporate unique layouts for the sensing elements, generally have essentially identical sensor arrays with sensing elements aligned in proximity to the drive elements, and conductive pathways that promote cancellation of undesired magnetic flux. These features enable the use of small sense elements that permits high resolution imaging of material properties.

Abstract: An exciting coil is constructed by winding a winding in a groove formed on the outer circumference of a circular ring member, and a detecting coil in the shape of a polygon (such as a triangle and a pentagon) when seen from the front is positioned. One side of the detecting coil is placed in a diameter direction of the exciting coil, inside the exciting coil, and the vertex opposite to the one side is placed apart from the exciting coil so that the detecting coil is orthogonal to the exciting coil. A side surface of the exciting coil on the side opposite to the vertex is placed to face the surface of a test material, and used as a flaw detection surface.

Abstract: The present invention provides an apparatus and method for measuring nonferrous electrical resistance measurement. The method includes providing a nonferrous material, inducing a magnetic field on the nonferrous material, measuring the remote magnetic field of the nonferrous material, and comparing the measured remote magnetic field to a standard.

Abstract: Apparatus and methods for measuring cross sectional area and flaws in a continuous sucker rod string as the string is conveyed within a borehole. These measured parameters are useful is monitoring the physical integrity of the sucker rod string. A magnet is used to saturate an increment of continuous sucker rod, and a coil is used to measure induced flux. Cross sectional area of the rod increment is computed from the flux measurement. One or more Hall effect transducers are used to measure leakage from the increment as a function of distance along the increment. This measurement is used to detect and quantify the type of flaw within the rod increment being investigated. The process is repeated as the sucker rod string is conveyed into or out of the borehole.

Abstract: An axial direction groove is formed in a high permeability toroidal core taking the form of a pot core half with a mounting hole, a high cross-section ratio copper casing being tightly fit around core circumference, having poly-phase excitation windings shuttled through the mounting hole to encompass both the copper casing and the pot-core, forming an integral driving-sensing eddy current probe. A naked pot-core is wound as an integral driving-sensing probe. Poly-phase excitation of the probe is mesh-connected as a gramme-ring.

Abstract: In a non-destructive inspection device of the present invention which detects in a non-destructive manner a defect of a member to be inspected, based on a change in magnetic fluxes due to eddy currents that are generated by an inspection probe having a coil, a driving section which adjusts a position of the inspection probe, and measuring device for, based on a detection signal of the inspection probe, measuring a lift-off between the inspection probe and the member to be inspected are disposed. The driving section is controlled in accordance with a result of measurement of the measuring device, whereby a control of making the lift-off constant is performed.