Abstract: An electromagnetic ultrasonic double wave transducer, comprising a shell (1), and a permanent magnet assembly, a coil (4), a shielding layer (5), and a wire (6) which are provided in the shell (1). The permanent magnet assembly comprises a first permanent magnet (2) and a second permanent magnet (3) sleeved on the first permanent magnet (2). The magnetizing directions of the first permanent magnet (2) and the second permanent magnet (3) are perpendicular to the bottom of the shell (1), and the magnetic field directions of the first permanent magnet (2) and the second permanent magnet (3) are opposite. A non-conducting non-magnetic bushing material (9) is provided between the first permanent magnet (2) and the second permanent magnet (3), and upper end faces of the first permanent magnet (2) and the second permanent magnet (3) realize magnetic circuit closing by means of a magnetic circuit closing element (8).

Abstract: A system may be used for determining a parameter relating to a piston in an engine. The parameter may be the piston position, speed, etc., which may be determined at a reference point in a cylinder. The system may be controlled based on the determined parameter. The engine may be a linear reciprocating engine, opposed piston engine, etc. The system may include a first sensor provided on a base connected to the engine, and a second sensor provided on the base. The first sensor may be configured to generate a signal in response to a component coupled to the piston being in a region of the first sensor. The second sensor may be configured to generate a signal in response to a component coupled to the piston interacting with the second sensor. The system may include an energy transformer configured to transform motion of the engine to electrical power.

Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head including a read head, a write head, a heater and the magnetic head, and a sensor and the control section. The control section when applying electric power to the heater, the control section predicts, on the basis of a relationship between a value of the electric power to be applied to the heater and an output value of a spectrum at a pulse frequency of a DC output of the sensor in a state where pulsed electric power is applied to the heater, the output value of the spectrum, and detects contact between the magnetic head and the magnetic disk before the predicted output value of the spectrum becomes less than or equal to a threshold.

Abstract: A method, device, and computer readable medium for displaying a two-dimensional image of a viewed object simultaneously with an image depicting a three-dimensional geometry of the viewed object using a video inspection device is disclosed. The video inspection device displays a two-dimensional image of the object surface of a viewed object, and determines the three-dimensional coordinates of a plurality of surface points. At least one rendered image of the three-dimensional geometry of the viewed object is displayed simultaneously with the two-dimensional image. As measurement cursors are placed and moved on the two-dimensional image, the rendered image of the three-dimensional geometry of the viewed object is automatically updated.

Abstract: A method and device for automatically identifying a point of interest in a depth measurement on a viewed object using a video inspection device is disclosed. The video inspect device determines the three-dimensional coordinates in a region of interest on the viewed object and analyzes those surface points to determine the desired measurement application (e.g., determining the deepest point, the highest point, or the clearance between two surfaces). Based on the desired measurement application, the video inspection device automatically identifies the point of interest on the viewed object and places a cursor at that location.

Abstract: A robotic inspection system for bridge suspender cables includes a sensing device and a transport vehicle. The transport vehicle is configured to move the sensing device along a bridge suspender cable for taking main magnetic flux (MMF) readings as the sensing device moves along the bridge suspender cable. The system also includes a control station configured to wirelessly interface with the sensing device and the transport vehicle. In addition, the control station is configured to generate a bridge cable condition assessment report from the MMF readings to identify locations and sizes of deterioration of the bridge suspender cable.

Abstract: Systems and methods are provided for implementing and utilizing magnetic inspection machines with true gauss magnetic measurements.

Abstract: A method and device for automatically identifying a point of interest in a depth measurement on a viewed object using a video inspection device is disclosed. The video inspect device determines the three-dimensional coordinates in a region of interest on the viewed object and analyzes those surface points to determine the desired measurement application (e.g., determining the deepest point, the highest point, or the clearance between two surfaces). Based on the desired measurement application, the video inspection device automatically identifies the point of interest on the viewed object and places a cursor at that location.

Abstract: An imaging method and an imaging apparatus based on a magnetic flux leakage testing. The imaging method includes: selecting an imaging region having a corrosion defect on a pipeline to be tested; dividing the imaging region into a plurality of grid areas; scanning by a three-dimensional sensor array the pipeline to be tested so as to obtain magnetic flux leakage testing data; creating a three-dimensional orthogonal coordinate system in the imaging region, defining a first two-dimensional matrix of defect images according to the plurality of grid areas based on the three-dimensional orthogonal coordinate system, and creating a second two-dimensional matrix of magnetic flux leakage signals according to the magnetic flux leakage testing data based on the three-dimensional orthogonal coordinate system; and mapping the second two-dimensional matrix to the first two-dimensional matrix using a pre-trained wavelet neural network so as to image the corrosion defect.

Abstract: A method and device for automatically identifying the deepest point on the surface of an anomaly on a viewed object using a video inspection device. The video inspection device obtains and displays an image of the surface of the viewed object. A reference surface is determined along with a region of interest that includes a plurality of points on the surface of the anomaly. The video inspection device determines a depth for each of the plurality of points on the surface of the anomaly in the region of interest. The point on the surface of the anomaly having the greatest depth is identified as the deepest point.

Abstract: A method and device for automatically identifying a point of interest in a depth measurement on a viewed object using a video inspection device is disclosed. The video inspect device determines the three-dimensional coordinates in a region of interest on the viewed object and analyzes those surface points to determine the desired measurement application (e.g., determining the deepest point, the highest point, or the clearance between two surfaces). Based on the desired measurement application, the video inspection device automatically identifies the point of interest on the viewed object and places a cursor at that location.

Abstract: Systems and methods for imaging characteristics of a sample and for identifying regions of damage in the sample are generally described. Some example systems and methods for non-destructive evaluation of regions of material may operate in a direct current (DC) mode in which the system directly images regions of material where weak structural damage has occurred by imaging a self magnetic field generated by a DC electric current coupled through the material. Some example systems may operate in an alternating current (AC) mode to image regions of material where damage has occurred by generating a time varying magnetic field due to AC excitation coils inducing eddy currents in the sample, and imaging a magnetic field generated by the eddy currents around the regions of damage. The systems may use magneto-optical imaging techniques (MOI) to measure and map the magnetic field and channels of current flow in the material, for example.

Abstract: A system by which the proportion of ferromagnetic particles in a dielectric medium is measured. A magnetic field is generated by two signals in the medium: a low frequency feed and a relatively high frequency excitation. The feed magnetizes the ferromagnetic particles in the medium to the nonlinear range of the magnetization curve. The excitation is generated so that its spectrum is relatively wide and it is dense with frequency components. The level of the excitation is so high that the magnetic flux density in the medium corresponding to the excitation fluctuates nonlinearly, when the feed is at its peak value or near this. The magnetic field of the medium is measured by a secondary winding, and from the response signal produced by the sensor is detected the part resulting from the magnetic non-linearity, which part is the output signal. In the detection the response is multiplied by the signal, which arises magnetic field and includes the same random fluctuation as the response.

Abstract: A surge current detection device 30 is detachably attached to a conductor 11 and detects a surge current entering the conductor 11. The surge current detection device 30 includes: a holder 40 releasably holding the conductor 11 via first and second holder bodies 40-1 and 40-2 facing each other; a magnetic force concentrating member 60 having a substantially U-shaped cross-section, the magnetic force concentrating member 60 being secured inside the holder 40 and concentrating a magnetic flux included in a magnetic field generated by the surge current entering the magnetic flux conductor 11 to a high density at a predetermined detection region; and a magnetic material sheet 70 secured inside the holder 40 in such a manner that the magnetic material sheet 70 is positioned at the detection region, the magnetic material sheet 70 detecting the surge current.

Abstract: A protection element (e.g., an arrester) protects a piece of equipment to be protected, from surge currents line terminals and an earth terminal. Surge current detection devices are provided on respective conductors connected to the arrester. Each of the surge current detection devices is to detect the surge current penetrated into a conductor for a short period of time, and includes a magnetic flux concentration member by which a magnetic flux produced by the penetrated surge current is concentrated in a given detection area at a high density, and a ferromagnetic material sheet positioned on the given detection area. The ferromagnetic material sheet includes a recording layer which is able to record and erase the penetration state of the surge current. A plurality of microcapsules are arranged in the recording layer, and each of the microcapsules contains a suitable liquid, and a plurality of magnetic particles suspended in the suitable liquid.

Abstract: A position-sensing system magnetically senses the position of a piston rod moving with respect to a cylinder. A magnetically hard layer on the piston rod provides a recording medium. A track comprised of a plurality of magnetized regions is magnetized in the magnetically hard layer. A plurality of magnetic-field sensors is coupled to the cylinder in proximity of the magnetically hard layer to sense the magnetized track while the piston rod is moving with respect to the cylinder. A first one of the magnetic field sensors is positioned over the track to sense the magnetized regions of the track serially and a second one of the magnetic field sensors is positioned radially to one side of the track. The magnetic field sensors generate signals, in response to sensing the magnetized regions, for use in measuring rotational movement of the piston rod.

Abstract: According to one embodiment, a touch-down determining device, includes: an alternating current perturbation module configured to periodically perturb power of a heater by an alternating current, the heater adjusting protrusion amounts of a write magnetic pole and a read element of a magnetic head in a direction towards a recording medium; a change detector configured to detect a change in a spectrum level of a portion of a spectrum of a read signal read from the recording medium by the magnetic head receiving the power perturbed by the alternating current, the portion of the spectrum corresponding to the alternating current; and a touch-down determining module configured to determine whether touch-down is made, based on the change in the spectrum level detected by the change detector.

Abstract: A position-sensing system magnetically senses the position of a piston rod moving with respect to a cylinder. A magnetically hard layer on the piston rod provides a recording medium. Information is perpendicularly magnetized in regions of the magnetically hard layer. These regions provide an encoding scheme for determining the position of the piston rod. Magnetic-field sensors are positioned over redundant tracks of magnetically recorded regions. Each magnetic-field sensor positioned over a given track senses the same magnetized regions while the piston rod moves with respect to the cylinder. Other magnetic-field sensors can sense ambient fields for use in performing common-mode rejection. A write head can dynamically repair damaged or erased regions detected by the magnetic-field sensors. Energized by a battery-backup power source, the magnetic-field sensors and associated circuitry can continue to track movement of the piston rod when the machinery is off.

Abstract: Described is a piston rod position-sensing system having a cylinder and piston rod arranged in the cylinder for movement with respect thereto. A magnetically hard layer is formed on the piston rod to provide a recording medium. The magnetically hard layer is made of a cobalt-phosphorous (Co—P)-based alloy. A magnetic pattern is recorded in the magnetically hard layer. A magnetic field sensor located in the cylinder senses the recorded magnetic pattern while the piston rod is moving with respect to the cylinder.

Abstract: A wireless tamper detection sensor is defined by a perforated electrical conductor. The conductor is shaped to form a geometric pattern between first and second ends thereof such that the conductor defines an open-circuit that can store and transfer electrical and magnetic energy. The conductor resonates in the presence of a time-varying magnetic field to generate a harmonic response. The harmonic response changes when the conductor experiences a change in its geometric pattern due to severing of the conductor along at least a portion of the perforations. A magnetic field response recorder is used to wirelessly transmit the time-varying magnetic field and wirelessly detecting the conductor's harmonic response.

Abstract: Disclosed is a CCP-CPP-GMR head assembly which has: a CCP-CPP-GMR head that includes at least a current control layer having as a microstructure a plurality of truncated cone electric conductors with axes the same as a current direction and an insulator filling between the plurality of truncated cone electric conductors, and in which a surface on which a larger-area basal plane of the plurality of truncated cone electric conductors is greater in number is a first surface of the current control layer and a surface of an opposite side of the first surface is a second surface of the current control layer; and a sense current source providing the CCP-CPP-GMR head with a sense current that flows from the second surface to the first surface, a magnetic recording/reproducing apparatus having such a head, and a specification method of an appropriate sense current direction of the CCP-CPP-GMR head.

Abstract: A position-sensing system magnetically senses the position of a first component moving with respect to a second component. A magnetically hard layer on the first component provides a recording medium. Information is magnetically recorded in regions of the magnetically hard layer. These regions provide a relative encoding scheme for determining the position of the first component. Magnetic-field sensors are positioned over redundant tracks of magnetically recorded regions. Each magnetic-field sensor positioned over a given track senses the same magnetized regions while the first component moves with respect to the second component. Other magnetic-field sensors can sense ambient fields for use in performing common-mode rejection. A write head can dynamically repair damaged or erased regions detected by the magnetic-field sensors. Energized by a battery-backup power source, the magnetic-field sensors and associated circuitry can continue to track movement of the first component when the machinery is off.

Abstract: In at least one embodiment an apparatus is provided that includes an electromagnetic coupler probe to provide sampled electromagnetic signals and an electronics component to receive the sampled electromagnetic signals from the electromagnetic coupler probe and to provide recovered sampled electromagnetic signals. Other embodiments may be described and claimed.

Abstract: Described are system for recording piston rod position information in a magnetic layer on the piston rod. A piston rod has a magnetically hard layer formed thereon to provide a recording medium. A magnetic pattern is recorded in the magnetically hard layer. A magnetic field sensor disposed adjacent to the piston rod senses the recorded magnetic pattern while the piston rod is moving and generates signals in response to the magnetic pattern that are used to determine a position of the piston rod.

Abstract: A device and method for validating a ticket having magnetic ink printed on at least one side of a ticket. The ink is magnetized to create a magnetic signal in the magnetic ink and thereafter a media reader sensor spaced from the ticket is used to verify the existence of a magnetic signal. The magnetic signal is comparable to pre-existing data to determine a match and/or validate tickets having a match. An optical reader can be used to obtain additional data stored in the form of bar codes or patterns on the printed magnetric ink. The optical signal is comparable to pre-existing data to determine a match and/or validate tickets having a match. Preferred comparators for magnetic and optical matching are microprocessors and preferred media reader sensors for magnetic readers are anisotropic magnetoresistive sensors.

Abstract: A position-sensing system magnetically senses the position of a piston rod moving with respect to a cylinder. A magnetically hard layer on the piston rod provides a recording medium. Information is magnetically recorded in regions of the magnetically hard layer. These regions provide a relative encoding scheme for determining the position of the piston rod. Magnetic-field sensors are positioned over redundant tracks of magnetically recorded regions. Each magnetic-field sensor positioned over a given track senses the same magnetized regions while the piston rod moves with respect to the cylinder. Other magnetic-field sensors can sense ambient fields for use in performing common-mode rejection. A write head can dynamically repair damaged or erased regions detected by the magnetic-field sensors. Energized by a battery-backup power source, the magnetic-field sensors and associated circuitry can continue to track movement of the piston rod when the machinery is off.

Abstract: The present invention is a device for and method of viewing a magnetic pattern recorded on magnetic media. The device includes a base. The base has an opening and includes registration marks for aligning the magnetic media as desired. The base is attachable to a viewer. A guide is connected to the base so that it slides within the opening in the base. The guide also has an opening. An inflatable bladder is attached to, and under, the guide. The inflatable bladder fills the opening in the guide. A holder is attached to the base so that it can slide along the base and be closed onto the guide. The holder also includes an opening. A magnetic garnet film is set within the opening in the holder. A magnetic media is placed on the guide. The holder is closed onto the magnetic media and the guide. The inflatable bladder is inflated so that the magnetic media is brought into physical contact with the magnetic garnet film. The pattern on the magnetic media is transferred onto the magnetic garnet film.

Abstract: A magnetic head and disk tester comprises a base, a spindle for rotationally supporting a magnetic disk, a carriage for supporting a magnetic head support which carries a magnetic head with a magnetic read/write element, and a dual-stage positioning system that moves the carriage in two perpendicular directions X and Y. The magnetic head support, the magnetic head and the magnetic read/write element have a common longitudinal axis Z. The head support is positioned such that the longitudinal axis Z forms a predetermined angle between 0° and 90° with respect to the Y direction. Preferably the predetermined angle is about 45 degrees. When the head is driven from one point of an inner track to a point of an outer track, the displacement of the head along X axis is relatively large and the displacement of the head along Y axis is relatively small.

Abstract: Described are systems of recording piston rod position information in a magnetic layer on the piston rod. A piston rod moving with respect to a cylinder has a magnetically hard layer formed thereon to provide a recording medium. A magnetic pattern is recorded in the magnetically hard layer. A magnetic field sensor senses the recorded magnetic pattern while the piston rod is moving with respect to the cylinder and generates signals in response to the magnetic pattern that are used to determine an instantaneous position of the piston rod.

Abstract: Described are a system and method of recording piston rod position information in a magnetic layer on the piston rod. A piston rod moving with respect to a cylinder has a magnetically hard layer formed thereon to provide a recording medium. A magnetic pattern is recorded in the magnetically hard layer. A magnetic field sensor senses the recorded magnetic pattern while the piston rod is moving with respect to the cylinder and generates signals in response to the magnetic pattern that are used to determine an instantaneous position of the piston rod.

Abstract: A writer coil in a data head of a data storage system is tested by coupling detection circuitry to the writer coil and driving the writer coil with a periodic pulse signal generated by the detection circuitry. As a result, voltage is generated, with the detection circuitry, as a function of an inductance of the writer coil. An inductance of the writer coil is calculated as a function of the generated voltage. Electrical short circuits and discontinuities in the writer coil are identified as a function of the calculated inductance.

Abstract: An invention including an outer shell that can be used to provide separated conductors and a method for installing a conductor in the outer shell is disclosed. The invention can assume many different embodiments. The outer shell is adapted to retain a conductor and includes a base adapted to associate with a support surface. The outer shell also includes a hollow sensing portion that extends from the base and is adapted to retain a conductor. The sensing portion is spaced from the base a distance sufficient to accommodate a portable, hand-held current sensing device. The invention also includes a method of installing a conductor in the hollow sensing portion.

Abstract: A circuit and method for detecting an abnormality in a recording head, wherein a voltage detection circuit detects a counter electromotive voltage generated across the two terminals of a recording head to which a recording current is supplied from a recording circuit; a processing circuit generates the maximum, minimum, and mean voltages from the counter electromotive voltage; a discrimination circuit using these voltages determines whether an abnormality occurs in the recording head. An output circuit outputs the result. With this operation, an abnormality in the recording head having two terminals in an MR head can be detected with a high precision.

Abstract: Techniques for ultrahigh density writing on an erasable magnetic medium include using a micromachined mechanism having two probes for writing to the medium. Use of the two probe embodiment eliminates the need to change the magnetic orientation of the probe. In another embodiment, a single probe is provided which is heated to the vicinity of its Curie temperature to enable the magnetic orientation of the probe to be switched. The probe may be heated to its Curie temperature through the use of a heating element or a focused laser. In another embodiment of the present invention, either the magnetic orientation of the probe or the magnetic orientation of the medium may be switched through the combination of a static magnetic field, a radio frequency magnetic field and, under certain circumstances, the magnetic field of the probe. In all cases, the writing techniques enable information to be written to a magnetic medium in a manner which enables the information to be erased and the medium rewritten.

Abstract: A magnetooptic device to be used in industrial applications to investigate articles for flaws or defects. The magnetooptic device is capable of revealing defects in articles of nonmagnetic and magnetic conducting material. These results are achieved by designing a magnetooptic device having a magnetooptic transformer element on its bottom surface and incorporating a front electrical contact and a rear electrical contact on the bottom surface of the MO device. The respective electrical contacts are connected by wire conductors to the respective positive and negative terminals of a source of electrical current. The defect pattern of an article can be either visually viewed or the defect pattern can be recorded on a tape or magnetic rubber sheet placed between the bottom surface of the MO device and the top surface of the article being analyzed.

Abstract: An apparatus and method for providing a fine line resistance image of a conductive pattern. A magnetic recording medium is placed in close proximity to the conductive pattern and a varying magnetic field is applied to the conductive pattern such that eddy currents in the conductive pattern are created. The eddy currents produce a magnetization pattern indicative of line resistance. The applied magnetic field is time varying and the varying magnetic field may be applied perpendicular to the recording medium or it may be applied in the plane of the recording medium.

Abstract: The present invention relates to an antidegradant system comprised of (A) an antidegradant selected from the group consisting of phenolic antidegradants, amine antidegradants and mixtures thereof; and (B) a unique polymerizable synergist. In addition, there is disclosed a stabilized polymer comprising (A) a polymer selected from the group consisting of (1) homopolymers and copolymers of monoolefins; (2) natural rubber; and (3) synthetic rubber derived from a diene monomer; (B) from about 0.05 to about 10 parts by weight based upon 100 parts of polymer of an antidegradant selected from the group consisting of phenolic antidegradants, amine antidegradants and mixtures thereof; and (C) from about 0.05 to about 20 parts by weight based upon 100 parts of polymer of a unique polymerizable aromatic sulfide synergist.

Abstract: A process for mapping the path of an electric arc through a sample of resive material whereby the magnetic field propagated by the arc is recorded on a sleeve of magnetic sensitive material which surrounds the sample, with the intensity of the recorded field at different points on the sleeve indicating the path of the arc.

Abstract: A device for the direct visualization of surface and near surface cracks, voids, flows, discontinuities, etc. in a target material. A magnetic garnet epitaxial film is deposited on either side, or both sides, of a non-magnetic substrate. A reflective material is provided adjacent to the epitaxial film, and the substrate with its associated layers is placed over a sheet of current carrying material and this sheet is placed over the target material. A bias magnetic field is then applied to the substrate together with its epitaxial film. Polarized light is transmitted onto the substrate with its associated layers and is reflected through the epitaxial layer and back out of the substrate. The existing magnetization, within the epitaxial film, interacts with nearby magnetic fields associated with eddy currents flowing adjacent to flaws in the target material, such that the domain structure of the epitaxial film is altered.

Abstract: A leakage flux flaw detection method and apparatus comprising applying one surface of a magnetic recording material to the test surface of a test material and overlaying the other surface of the magnetic recording material with a layer of magnetic material with the intervention of a non-magnetic layer, and the use of a magnetizer and an auxiliary recording member provided with layers of magnetic and non-magnetic materials.

Abstract: A device for magnetographic quality inspection of a material, whereby a magnetic-recording medium is applied onto the material to be inspected, and they are together magnetized so that the resulting magnetogram can be used to assess the quality of the material. According to the invention, the intensity of the magnetizing field is established by the maximum curvature of the surface of a drop of a magnetic fluid applied onto the surface of the material to be inspected. A magnetic substance is placed between the magnetic-recording medium and the material so that the surface of the latter is smoothed out. The magnetizing device includes a magnetic yoke and a magnetizing coil loosely fitted thereon and composed of sections which are connected in parallel to one another.

Abstract: A magnetizer for magnetographic inspection of articles comprises a main electromagnet, an auxiliary electromagnet, and a power supply unit for the windings of the electromagnets. The auxiliary electromagnet is offset with respect to the central zone of the magnetic field established by the main electromagnet, in a direction perpendicular to that of the magnetic lines of force of the main electromagnet, and is mounted for changing its position.

Abstract: A method of magnetographic quality inspection of a material, whereby a magnetic-recording medium is applied onto the material to be inspected, and they are together magnetized so that the resulting magnetogram can be used to assess the quality of the material. According to the invention, the intensity of the magnetizing field is established by the maximum curvature of the surface of a drop of a magnetic fluid applied onto the surface of the material to be inspected. A magnetic substance is placed between the magnetic-recording medium and the material so that the surface of the latter is smoothed out. A magnetizing device comprising a magnetic yoke and a magnetizing coil lossely fitted thereon and composed of sections which are connected in parallel to one another.

Abstract: A method for the direct visualization of surface and near surface cracks, voids, flaws, discontinuities, etc. in a material is disclosed. The detection of flaws or the like is accomplished by the visualization of the static and/or dynamic magnetic fields, either ambient or induced, associated with various flaws in a target material. A magnetic garnet epitaxial film is deposited on either side of a non-magnetic substrate. In one embodiment, a reflective coating or material is provided adjacent to the epitaxial film, and the substrate with its associated layers is placed over the target material. A magnetic field is then applied to the target material and substrate. Polarized light is transmitted onto the target material and is reflected through the epitaxial layer and back out of the substrate. The existing magnetization within the epitaxial film interacts with nearby magnetic fields associated with near surface flaws in the target material, such that the domain structure of the epitaxial film is altered.

Abstract: A magnetizing device includes a two-pole electromagnet with four rollers mounted in pairs on the poles of the electromagnet and interacts with a respective guide. These guides are made as rings. The rollers are mounted on the poles by means of half-axles which are secured on each roller with a displacement in relation to the rotation axle of the roller.

Abstract: A method for the direct visualization of surface and near surface cracks, voids, flaws, discontinuities, etc. in materials is disclosed. The detection of flaws or the like is accomplished by the visualization of the static and/or dynamic magnetic fields, either ambient or induced, associated with various flaws in a target material. A magnetic garnet epitaxial film is deposited on a non-magnetic substrate. In one embodiment, a reflective coating or material is provided adjacent to the epitaxial film, and the substrate with its associated layers is placed over the target material. A magnetic field is then applied to the target material and substrate. Polarized light is directed onto the through the substrate and associated epitaxial layer, and is reflected by the reflective coating such that the polarized light passes back out of the substrate.

Abstract: Method and apparatus for magnetographic testing of magnetizable test pieces including pressing a magnetic storage tape upon the test piece, magnetizing the test piece thereof while the tape is being pressed against the test piece surface, removing the tape and scanning the tape by means of a probe which responds to magnetic forces to detect any stored defect stray fluxes.

Abstract: A magnetic tape using as recording medium selected magnetic or non-magnetic material is used for on-line physical and chemical analysis by exposure to selected external agents, physical or chemical, causing permanent alterations in the material, and changes in the magnetic properties of the materials are sensed to read out the recorded information in correlation with the analyzed phenomenon or process for storage, monitoring or control purposes.

Abstract: A magnetic testing device is provided in which a magnetic recording tape or paper is wrapped around the outside of a tubular pressure member of elastomeric material which is disposed between two circular end plates which form pole portions of a yoke having a central core extending between the end plates and having a coil wound thereon with a copper shield being disposed around the outside of the coil. The device is disposed in a pipe or the like and compressed air is supplied to inflate the pressure member and press the magnetic tape paper into intimate contact with the interior surface of the pipe while an AC current is supplied to the coil to apply a magnetic field to the pipe and to record a magnetic field pattern on the magnetic tape or paper.