Abstract: Systems and methods to use customized quality control tasks for non-destructive testing (NDT) are disclosed. An example NDT system includes at least one of a magnetic particle inspection device or a penetrant testing device, a user interface device, a processor, and a memory coupled to the processor and storing machine readable instructions. When executed, the instructions cause the processor to: access a quality verification procedure comprising a plurality of tasks and corresponding task definitions; display one or more of the plurality of tasks based on statuses of the plurality of tasks; receive one or more results associated with the one or more of the plurality of tasks; store the one or more results in association with the magnetic particle inspection device or the penetrant testing device; and control at least one aspect of the magnetic particle inspection device or the penetrant testing device based on the one or more results.

Abstract: A non-destructive inspection method of inspecting an inspection target using multiple different types of non-destructive inspection means that include one non-destructive inspection means and at least one other non-destructive inspection means. The method includes determining a marking position on the inspection target in a detection result by the one non-destructive inspection means, causing a device to store the marking position, and fixedly forming a mark on the inspection target corresponding to the marking position. The mark is detectable by the other non-destructive inspection means. The method further includes causing the other non-destructive inspection means to inspect an inspection target including the mark. The method further includes contrasting detection results by the multiple different types of non-destructive inspection means in reference to the mark which is the marking position.

Abstract: Provided is a disclosure for a magnetic particle inspection system configured to generate a magnetic field for inspection of a part, comprising a programmable logic controller (PLC), a current source, and a current sensing device. The PLC may be configured to communicate an amperage signal, for amperage of an output current, to a current source, and communicate a first signal to the current source to output the output current. The current source may be configured to adjust the amperage for the output current based on the amperage signal, and output the output current upon receiving the first signal. The current sensing device may be configured to measure an output amperage of the output current, and communicate amperage information based on the output amperage to a signal conversion device. The PLC may, in response to feedback from the signal conversion device, update the amperage signal.

Abstract: Provided is a base unit for wireless power transfer or charging through a time varying magnetic field, comprising. The unit may include one or more components including a magnetic material or layer, that guide a corresponding magnetic flux generated by a coil in the base unit in one or multiple dimensions and/or to guide the magnetic flux in such a manner as to create a preferential path for returning flux flow in one or multiple dimensions. When one or more power receivers, each having one or more receiver coils or receivers associated therewith, is placed in proximity to a base unit, the coil in the base unit is used to inductively generate a current in the one or more receiver coils or receivers associated with the one or more power receivers.

Abstract: Systems and methods for high-speed non-destructive inspection of a half- or full-barrel-shaped workpiece, such as a barrel-shaped section of an aircraft fuselage. Such workpieces can be scanned externally using a mobile (e.g., translating) arch gantry system comprising a translatable arch frame disposed outside the fuselage section, a carriage that can travel along a curved track carried by the arch frame, a radially inward-extending telescopic arm having a proximal end fixedly coupled to the carriage, and an NDI sensor unit coupled to a distal end of the telescoping arm. The stiffeners of the fuselage sections can be scanned using a mobile scanner platform disposed inside the fuselage section, which platform comprises a radially outward-extending telescopic arm rotatably coupled to a mobile (e.g., holonomic or linear motion) platform and an NDI sensor unit coupled to a distal end of the telescoping arm.

Abstract: The invention concerns a method and a device for the measurement of the volumetric capacity of a textured surface, especially a ceramic-coated laser-engraved metering roll, also called anilox roll, which is mainly used in the flexographic printing process, said metering roll comprising a plurality of cells designed to receive a predetermined quantity of a liquid, preferably ink, glue, varnish or a similar product to be transferred on the surface of a support. A ferrofluid is applied in the cells that compose the anilox roll surface, a magnetic field is generated close to the roll surface, the intensity of the magnetic field, increased by the ferrofluid, is measured and the volumetric capacity of the anilox roll is determined by measuring the increase in the magnetic field due to the presence of the ferrofluid.

Abstract: A through-transmission ultrasonic (TTU) inspection system for ultrasonic inspection of a part, such as an aircraft component. The TTU inspection system may include a first end effector and/or a second end effector. The first end effector may be positioned on a first surface of the part and the second end effector may be positioned on a second surface of the part, opposite the first surface. The first and/or second end effector may also include an acoustic coupling medium encircled by a plurality of pins independently movable toward and away from a housing of the first and/or second end effector, such that the pins may follow local part contours along the first surface at all times, while retaining the acoustic coupling medium between the first surface and a transducer in the housing of the first and/or second end effector.

Abstract: A method of inspecting a glass article using nuclear magnetic resonance imaging (NMRI). An NMRI-active filler material may be applied to the interior surface, the exterior surface, or both of the container. The excess material then may be removed leaving the filler within one or more anomalies on the surface of the container. And an NMRI analysis may be performed producing images associated with the anomalies having filler material therein.

Abstract: A magnetic particle inspection system for inspecting a plurality of articles. The system includes a first magnetizing coil for generating a first magnetic field oriented in a first direction. The system also includes a second magnetizing coil for generating a second magnetic field oriented in a second direction perpendicular to the first direction, wherein the first and second magnetizing coils are located in a common plane. In addition, the system may include a mat having a plurality of drainage holes, wherein the first and second magnetizing coils are located in the mat and the first and second magnetizing coils are sized to inspect a plurality of articles. Further, the system includes a power supply for supplying power for energizing the first and second magnetizing coils and a switching unit for switching current flow between the first and second magnetizing coils.

Abstract: An analog-digital conversion system includes an analog-digital converter; and a preamplifier circuit which is provided in the previous stage of the analog-digital converter and differentially amplifies an input analog signal. In the preamplifier circuit, an offset voltage and/or a noise occurs and/or is mixed. The preamplifier circuit outputs two types of analog amplified differential signals where a phase is inverted only with respect to the offset voltage and/or the noise. The analog-digital converter has an averaging circuit which averages the two types of analog amplified differential signals for each clock cycle of sampling preceding an analog-digital conversion and outputs a digital signal based on the differential signal averaged by the averaging circuit.

Abstract: A method relates to manufacturing a tubular link rod comprising a hollow body and, at each of the ends of this body, a connecting end. This method includes the following steps: a) manufacturing a one-piece component having the hollow body and a first end part that forms one of the connecting ends of a tubular link rod, b) assembling a second end part at the other end of the hollow body, and c) inspecting and/or machining an assembly zone on the inside of the hollow body, via a bore of the second end part establishing communication between the outside and the inside of the hollow body. This second end part forms the other connecting end of the link rod.

Abstract: The present invention relates to an apparatus and a method for void size determination of voids within an object into which an aerosol containing magnetic particles has been introduced, in particular for determining the size of a patient's pulmonary alveoli, said patient having inhaled an aerosol containing magnetic particles To review information concerning the lung structure, it is proposed to use magnetic particle imaging. First and second detection signals are acquired subsequently at different moments in time after introduction of the aerosol containing the magnetic particles into the object, in particular after inhalation of the aerosol by the patient. These detection signals are exploited, in particular the drop in intensity and/or the signal decay time, to get information about the diffusion of the magnetic particles within the voids, in particular alveoli, and to retrieve information therefrom about the size of the voids, in particular alveoli.

Abstract: A bench for magnetoscopically testing a tubular part, the bench including a tool of elongate shape for inserting inside the part and carrying an endoscopic mechanism for ultraviolet illumination of the inside surface of the part and for observing any defects of the part, and an indexing mechanism co-operating by mutual engagement with external references of the tool that are regularly distributed over at least a fraction of its length to control accurately the advance and the position of the tool inside the part.

Abstract: A non-destructive inspection system that has particular application for inspecting a bore in a valve for defects. The system includes an inspection yoke having a ferromagnetic core, where a first coil is wound around the core in one direction and a second coil is wound around the core in an orthogonal direction so that orthogonal electromagnetic fields can be generated within the bore. A controller provides a current flow through the coils to generate the electromagnetic fields to detect defects in the bore.

Abstract: Methods for testing for defects on magnetic media storage disks are provided. One such method includes dividing a surface of a magnetic media disk into a plurality of radial zones, dividing the disk surface into a plurality of concentric zones, thereby forming a preselected number (N) of wedge subsections for each of the concentric zones, scanning the disk surface for defects, counting the defects contained within each of the wedge subsections, summing the defects contained within two or more of the wedge subsections, comparing the summed defects with a preselected threshold, and determining, based on the comparison, a defect type of the disk.

Abstract: A magnetic inspection station for tubular members and methods for operating the same have a longitudinal flaw detection assembly adapted to pass a circumferential magnetic field through a tubular member and a transverse flaw detection assembly adapted to pass a longitudinal magnetic field through the tubular member. The magnetic fields cause congregation of a ferromagnetic particles sprayed on the tubular member in a magnetic particle inspection fluid. The congregation of ferromagnetic particles indicates a flaw in the tubular member. The magnetic inspection station includes a clamping apparatus positioned closely adjacent to the magnetic inspection station and adapted to support the tubular member within the magnetic inspection station and exert a compensating force on the tubular member to resist the magnetic forces generated by the longitudinal flaw detection assembly and the transverse flaw detection assembly.

Abstract: It is an object of the present invention to provide an eddy current testing apparatus capable of accurately detecting any flaws occurring in a columnar or cylindrical subject to be tested regardless of their extending directions, with the use of the same probe coil. The eddy current testing apparatus 100 according to the present invention comprises a spinning plate 1 and a probe coil 2 disposed on the spinning plate 1. The probe coil is a probe coil capable of obtaining a differential output about a scanning direction of a detection signal which corresponds to a detected eddy current induced in the subject to be tested. The spinning plate is disposed in such a position that a spinning center RC of the spinning plate faces with an axial center PC of the subject to be tested.

Abstract: In a method for determining geometrical characteristics (d) of an anomaly (12) which changes the electrical conductivity in the region near the surface of an electrically conducting, in particular a metallic test object (10), a considerable simplification is achieved in that, in the region of the anomaly (12) in the test object (10), eddy currents (13, 14) of different frequencies are excited, and the magnetic field (By,0), which is produced by the excited eddy currents, is scanned in the vicinity of the anomaly (12) and the geometric characteristics of the anomaly are exclusively deduced from the distribution of the magnetic field (By,0).

Abstract: A segmented magnetostrictive patch array transducer capable of generating a high frequency shear wave in a structure such as a rod or a pipe, a structural fault diagnosing apparatus including the segmented magnetostrictive patch array transducer, and a method of operating the segmented magnetostrictive patch array transducer are shown. The segmented magnetostrictive patch array transducer includes a plurality of magnetostrictive patches attached along a circumference of a rod member; a plurality of insulators that are disposed on the magnetostrictive patches; a plurality of meander coils, each of the meander coils comprising a plurality of coil lines extending along the circumference direction of the rod member on each of the insulators, wherein a current flows through adjacent coil lines in opposite directions to one another; and a plurality of magnets that respectively form a magnetic field along the circumferential direction of the rod member on the magnetostrictive patches.

Abstract: A magnetic particle inspection (MPI) apparatus is disclosed that includes a chordal field coil pair and a radial field coil pair. The chordal field coil pair includes first and second chordal field coils configured to produce a chordally oriented magnetic flux about a test article.

Abstract: A method of eddy-current flaw detexction where an exciting device and a receiving device are held in the vicinity of a conductor. An eddy current is generated in the conductor by a primary magnetic field generated by excitation, thereby generating a secondary magnetic field, wherein the state of the magnetic field is detected by the receiving device. The exciting device includes a coil and an iron core. The coil has a first current line and a second current line in which electric current flows in opposite directions. The iron core is gate-shaped in cross section and includes a first leg portion, a second leg portion, and a beam portion. The receiving device is disposed in a corner between the second leg portion and the conductor, on a side opposite the second current line on the outer side of the iron core.

Abstract: A bench for magnetoscopically testing a tubular part, the bench including a tool of elongate shape for inserting inside the part and carrying an endoscopic mechanism for ultraviolet illumination of the inside surface of the part and for observing any defects of the part, and an indexing mechanism co-operating by mutual engagement with external references of the tool that are regularly distributed over at least a fraction of its length to control accurately the advance and the position of the tool inside the part.

Abstract: A method for inspecting semiconductor wafers patterned by a photomask includes loading a first wafer and scanning a first image of the first wafer, loading a second wafer and scanning a second image of the second wafer, comparing the first and second images, and classifying a difference detected between the first and second images as a potential defect on the photomask. The potential defect includes a haze defect on the photomask.

Abstract: The invention relates to a manual lamp, especially for optical crack testing according to the magnetic powder testing and dye penetration method. Said manual lamp comprises at least one LED having an emission wavelength located in the UVA range as an illuminating means.

Abstract: A system for inspecting a pipe weld from within a pipe through use of magnetic particle imaging “MPI” includes an apparatus having a head unit that carries a wire wheel brush for cleaning an inspection area along an inner diameter of a pipe weld, and an MPI medium dispenser for spraying an MPI medium upon the inspection area, both controlled by an operator. The head unit also includes a video inspection device controlled by the operator and used for viewing at least portions of the inspection area after being sprayed with the MPI medium and when under the influence of a magnetic field to determine if the weld has any defects. The head unit is connected to a drive unit. The drive unit includes a frame having a longitudinal axis and mounted on a set of drive wheels, and a set of support wheels spaced axially from the drive wheels.

Abstract: A method of designing a small-sized, self-shielding magnetic field gradient coil assembly that is for use in an NMR spectrometer, provides high approximation accuracy, is simple in structure, and has a large inside diameter. The gradient coil assembly consists of tightly wound inner and outer coils. The designing process starts with setting or resetting the number of the inner coils and the number of turns of each inner coil. Their positions are optimized such that the magnetic field gradient strength falls within a tolerable range under shielded condition. Then, the number of the outer coils and the number of turns of each outer coil are set. The Fourier components of a current distribution necessary for the outer coils are calculated.

Abstract: A system for inspecting a pipe weld from within a pipe through use of magnetic particle imaging “MPI” includes an apparatus having a head unit that carries a wire wheel brush for cleaning an inspection area along an inner diameter of a pipe weld, and an MPI medium dispenser for spraying an MPI medium upon the inspection area, both controlled by an operator. The head unit also includes a video inspection device controlled by the operator and used for viewing at least portions of the inspection area after being sprayed with the MPI medium and when under the influence of a magnetic field to determine if the weld has any defects. The head unit is connected to a drive unit. The drive unit includes a frame having a longitudinal axis and mounted on a set of drive wheels, and a set of support wheels spaced axially from the drive wheels.

Abstract: An ultraviolet light permeable filter for an ultraviolet detection light is equipped on a filter glass surface with a dielectric multi-film layer which allows a visible radiation of wave length from 694 nm to 780 nm to reflect on the layer. The 694 nm to 780 nm wave length does not penetrate through the multi-film layer. When placed in an ultraviolet detection system, this filter prevents the occurrence of a reddish halation during inspection and display of a flaw detection light.

Abstract: A reference standard and method for inspecting dual-layered coatings. The reference standard has a first layer adherent to a substrate, the first layer has a predetermined thickness that increases in one direction. Adherent to the first layer is a second layer, the second layer has a predetermined thickness that increases in a direction orthogonal with the first layer. The orientation of the first and second layers of the reference standard provides a spectrum of the possible variations of the dual-layered coating.

Abstract: A method and apparatus is shown for implementing magnetostrictive sensor techniques for the nondestructive evaluation of railroad rails. The system includes magnetostrictive sensors specifically designed for application in conjunction with railroad rails and trains that generate guided waves in the railroad rails which travel therethrough in a direction parallel to the surface of the railroad rail. Similarly structured sensors are positioned to detect the guided waves (both incident and reflected) and generate signals representative of the characteristics of the guided waves detected that are reflected from anomalies in the structure such as transverse defects. The sensor structure is longitudinal in nature and generates a guided wave having a wavefront parallel to the longitudinal axis of the sensor, and which propagates in a direction perpendicular to the longitudinal axis of the sensor. The generated guided waves propagate in the rail within the path of the propagating wave.

Abstract: An inspection station and process for pipe or other ferromagnetic articles utilizes a generally straight flux field amplifier made of a multi-stranded cable surrounded by non-conducting resin, for inducing transverse lines of magnetic force. The flux field amplifier is surrounded by a coil which is also energized to make longitudinal lines of force; the two types of lines of force are vectored. The pipe or other ferromagnetic article is sprayed with UV-sensitive magnetic particles in a more or less conventional manner to display the vectored lines of force together with any flaws in the metal. The cable core of the flux field amplifier does not need a cooling system and is able to last longer than conventional solid cores.

Abstract: A plurality of magnetic field members are provided, each for selectively generating a time-varying magnetic field for combination into a o time-varying composite longitudinal magnetic field with magnetic flux lines which are substantially aligned with the central longitudinal axis of the cylindrical ferromagnetic member. Additionally, a traverse magnetic field member is provided which selectively generates a time-varying traverse magnetic field with magnetic flux lines which are substantially traversed to the central longitudinal axis of the cylindrical ferromagnetic member. The plurality of magnetic field members and the traverse magnetic field member are maintained out of contact with the cylindrical ferromagnetic member. Magnetic particles are placed on selected portions of the cylindrical ferromagnetic member. A time-varying composite longitudinal magnetic field and a time-varying traverse magnetic field are applied to the cylindrical magnetic member, while it is being rotated.

Abstract: Field strength of an electromagnet is monitored at a threshold with a coupling coil positioned to monitor magnetic flux in a leg of an electromagnet. In the context of magnetic particle inspection for surface flaws (e.g. cracks) in ferromagnetic materials, sensing magnetic flux in a portion of a magnetic circuit including the material being inspected provides a continuous direct indication of whether or not the magnetic field strength produced is sufficient for reliable inspection to be performed. Since the magnetic flux in the electromagnet will be reduced with increases in reluctance of the magnetic circuit, the continuous monitoring of magnetic field strength also effectively monitors correct inspection technique by the magnetic particle inspection methodology.

Abstract: A method and an apparatus for obtaining a displacement condition of a track in a longitudinal direction thereof on a magnetic tape on which a periodic signal is recorded by detecting a signal position from image information obtained by imaging said track while moving the magnetic tape and/or the image device in the longitudinal direction of the track.

Abstract: Apparatus for measuring flux density within the surface of a ferromagnetic material (24) includes a probe (10) having an end for location on or adjacent the surface of the material (24), a first sensor at the said end of the probe (10) and capable of producing a first output signal representative of the strength of the magnetic field to which said first sensor is subjected, and a second sensor at the remote end of the probe (10) and capable of producing a second output representative of the strength of the magnetic field to which said second sensor is subjected. An electronic circuit produces a difference signal representing the difference between the first and second outputs, and an output device (14) displays and/or records said difference signal (16).

Abstract: A field strength indicator for a magnetic particle inspection process is used to determine field strength and direction sufficient to identify real flaws in a test piece. The field strength indicator is a substantially flat shim having at least one series of artificial flaws formed therein by electric discharge machining. The artificial flaws have a geometry which render them compatible with real flaws and thus enable the magnetic field strength and direction to be properly set for conducting a magnetic particle inspection procedure. The surface containing the artifical flaws must be covered with a thin inert and non-magnetic coating for proper operation.

Abstract: A magnetic particle inspection system includes apparatus for applying a magnetic field to an inspection area of a metal structure. This apparatus comprises a power cable arranged in at least one cable inspection loop to which electrical power is connected. In this way the adjacent inspection area is magnetized. The inspection aea is sprayed with disclosing fluid and an ultra violet light illuminates the sprayed area. The length of the cable inspection loop is adjustable so that the area of the inspection area can be varied. The apparatus is particularly designed to be mounted on a remotely operated vehicle.

Abstract: An apparatus for producing a uniform magnetic field in a test sample having an angled end during a magnetic particle test procedure, includes a conductive, angled fixture having a contact surface and an overall shape corresponding to that of the angled end of the test sample, so that when a pulsed current is passed through the blade, the resulting uniform magnetic field permits detection of defect indications in the angled end.

Abstract: Method and apparatus for inspecting weld seams by means of particles of magnetizable material which align themselves in a magnetic field in a manner characteristic of faults the particles are suspended at the start of a test in a first liquid Fl.sub.1, the particles being freely mobile in the suspension and no viscosity change of the suspension taking place. Thereafter a substance is added to the suspension which effects a change of state, the particles aligned in the magnetic field thereby being fixed in their position.

Abstract: A flux scanner head generates a unidirectional magnetic field external to the head adjacent a scanning surface thereof. Workpieces to be subjected to magnetic particle inspection may be successively passed through, held in, or otherwise associated with, the unidirectional field at different angles to achieve magnetization along multiple axes, without physical or electrical contact with the workpiece. The scanner head is usable with both residual and continuous methods of magnetic particle inspection, and as either a hand-held or fixed-mount system. The scanner head itself incorporates a coil having a plurality of turns with a ferromagnetic core separating such turns so as to intensify and direct outward and external to the surface of the scanner head the magnetic field generated by current flow through the coil.

Abstract: A ferrous metal inspection device particularly for elongated parts provides high intensity DC magnetic fields in each of two modes contemporaneously. One mode is generated by passing a DC current axially through the part to be inspected and the other is generated by a separate DC current passing through a pair of electromagnet coils positioned one at each axial end of a part to be inspected. Magnetic field lines are thereby generated in a pair of mutually orthogonal planes. Control and polarity of the two direct currents is effected by controlling the phase of conduction of separate corresponding silicon controlled rectifiers. The part to be inspected is drenched with a mixture of fine ferrous particles in a liquid vehicle. Solenoid wound coils connected in series or parallel are placed, one at each end of the part and a third coil surrounds the part circumferentially, thereby producing two substantially orthogonal magnetic fields.

Abstract: For marking and finding weld seams to be investigated under water ultrasonic transmitters 54 are provided which have luminous or light-reflecting characters 58. The diver brings an ultrasonic receiver 60 up to the ultrasonic transmitter 54. For more exact location determination along the weld seam 52 a tape is provided which is disposed along the weld seam 52 and has elements arranged in coded manner.

Abstract: A method for inspecting the surface of a workpiece for the presence of flaws using a ferrofluid as a penetrant which is applied to the surface of the workpiece and then scanning the surface of the workpiece with electrical detection means placed adjacent to the surface for providing responses indicative of the presence of flaws in the surface of the workpiece. If desired, a magnetic field can be used to induce the flow of the ferrofluid into any flaws prior to inspection, and for post-inspection cleanup as well. By the use of a ferrofluid, the sensitivity of the electrical detection means, advantageously of the eddy current type, is enhanced in typical applications, and also allows the use of an eddy current probe to inspect workpieces made of nonconductive and/or nonferromagnetic materials.

Abstract: The present invention relates to a method for detecting defects in metal structures and welds, especially under-water structures. The method involves applying to the surface of the suspected area of the defective structure a fast curing, cold cure impression material, curing the impression material into a solid cast and lifting off the cured cast as a three dimensional profile of the defect. The impression material may be used in conjunction with a magnetic ink which forms on the defective surface a cluster of magnetic particles, termed "indication", simulating the defect and this "indication" can be lifted off on a cast of the impression material as previously. The preferred impression material is maleinised polybutadiene.

Abstract: A dry magnetic particle bath for non-destructive testing of a magnetizable workpiece to detect flaws comprising magnetic particles, a modified dextrose adhesive, and a carrier powder. In certain other embodiments of the invention the magnetic particle bath is instead a wet bath comprising water, magnetic particles, and modified dextrose. According to the invention, the wet bath can also contain an anti-freeze component consisting essentially of urea and ethylene glycol, glycerine or monoethanolamine to depress the freezing point of the water bath to 10.degree.-15.degree. F.; the invention encompasses wet bath formulations which contain the anti-freeze component in combination with adhesives other than modified dextrose.

Abstract: An aqueous system for testing magnetizable articles is provided by a water based slurry of magnetic particles including a corrosion inhibitor, surface tension adjusting agent, an antifoam agent, a viscosity adjustment element, and a buffering element to assist in the corrosion resistance.

Abstract: Elongated ferromagnetic parts of cylindrical or polygonal cross-sectional outline are tested while rotating about their axes and while advancing longitudinally along a cushion of dry pulverulent magnetic material which is supplied by one or more pneumatic conduits into the range of one pole of a first U-shaped electromagnet whose poles extend in the longitudinal direction of but do not contact the parts. The electromagnet establishes a stray magnetic flux in the region of each defect on the ferromagnetic part which is being tested and such flux or fluxes attract pulverulent material which thereby pinpoints the locations of defects. A second electromagnet is placed next to the one pole of the first electromagnet and its poles are spaced apart from each other as considered in the longitudinal direction of the tested part.

Abstract: A non-destructive inspection arrangement for ferrous and non-ferrous metallic workpieces. The inspection arrangement employs a liquid crystal indicator medium and electrical current flow through the workpiece to develop potential differences across work surface flaws that are to be detected. The concepts of direct application of the liquid crystal medium to the work area surface and containment of the liquid cyrstal medium within a viewing device are also included.

Abstract: A metal body is inspected for defects by relatively longitudinally displacing it and a plurality of pairs of coils connected in respective bridge circuits that are excited with alternating current. The coils are also excited with alternating current so that eddy-current variations caused by defects in the body become impedance variations of the coils which in turn become imbalance signals in the respective bridges. The imbalance signals are demodulated to form respective imbalance voltages which are periodically sampled and the levels of the sampled demodulated voltages are stored. The sampled demodulated voltages of each bridge are averaged to produce respective base lines which are compared with the respective stored levels of each sampled voltage for generation of respective error signals corresponding to the differences. These error signals are compared with a first relatively low threshold corresponding to the smallest defect to be detected and with a second relatively high threshold.

Abstract: An automatic overhead trolley-driven magnetizing system for inducing a residual magnetic field in seamless steel pipe in order to detect non-visual defects therein by the magnetic particle inspection method is described. The magnetizing system consists of a trolley-driven magnetizing unit which moves on an overhead runway until a retractable limit switch causes the unit to stop upon reaching the trailing end of the pipe, an electrical contact pad then lowers onto the surface of the pipe, and introduces a magnetizing current to the pipe sufficient to cause magnetic particles deposited on the pipe surface to indicate the location of defects in the pipe. The magnetizing system is arranged to remain remote from the manufacturing flow path of the workpiece until the magnetization thereof is required.