Abstract: A method and apparatus for sizing a surface-connected planar crack through a gas- or liquid-filled gap. Ultrasonic energy having a frequency equal to the resonant frequency of the gap is emitted toward the crack edge. A first portion of the energy is back-scattered by the crack edge toward the emitter in a detection mode and a second portion is scattered by the crack edge toward a surface to which the crack is connected, which reflects the second portion toward a detector. The difference between the respective times-of-flight from emission to detection of the first and second portions is measured and used to determine the depth of penetration of the surface-connected crack. The paths traveled by the first and second portions of said emitted ultrasonic energy substantially intersect at the gap. A similar method also applies in sizing buried planar cracks across fluid-filled gaps.

Abstract: A method for internal inspection of pieces having an interface with a propagation medium, is described. The steps include: illuminating a reference piece with an ultrasound beam from a first array of transducers excited by stored excitation signals; sensing reflected echo signals received by transducers, which may be the transducers of the first array, and storing the waveforms and time distribution thereof; simultaneously sensing refracted signals, received by transducers belonging to a second array placed opposite to the the first relative to the piece and storing the waveforms and time distribution of the signals received by the transducers of the second array; replacing the reference piece with a piece to be inspected having the same shape and occupying the same location, and applying, to each of the transducers, energization signals obtained by time reversal of the stored waveforms and time distribution; and sensing the signals received by the transducers of the second network.

Abstract: This invention defines a combined inspection procedure using ultrasonic techniques for detection of hydrogen attack damage in material. The procedure comprises an initial scanning procedure for locating areas suspected of being damaged by hot hydrogen. The initial scanning procedure is a pattern-based backscattering test that provides a pattern which is classified as falling within at least one of four backscattering pattern category types. Follow-up test procedures based upon the pattern type are then performed. These tests include spectrum analysis, velocity ratio, spatial averaging backscattering, and frequency dependence for assessing whether the material has hydrogen attack damage and the extent of hydrogen damage in the suspect areas. Should hydrogen attack damage be identified, the velocity ratio and spectrum analysis tests can then be used to determine mechanical properties of the hydrogen attack damaged material.

Abstract: A method for the non-destructive evaluation of the integrity of wooden members, in situ, for example, embedded in the soil, employing the reflection of an acoustic wave off of the embedded end of the wooden member. The reflection is caused by the discontinuity in acoustic properties between wood and the supporting medium. The method allows the measurement, at one end of the member, of substantially the entire length of the wooden member without its removal. The acoustic wave is monitored in time and amplitude to provide indications of sound speed and attenuation, measurements which apparently are not unduly affected by coupling losses between the wooden member and its supporting matrix. These measured values may be empirically linked in an equation providing the integrity of the wooden member.

Abstract: The presence of a crack in a material and the orientation of the crack is determined by placing a transducer on the surface of the material for propagating a shear wave for reflection off of the back wall of the material. The reflected signal is evaluated such that no signal or a weak signal indicates the presence of a crack. The transducer is then held in place and rotated while propagating a shear wave in order to determine the orientation of the crack. The reflected shear wave is then evaluated in the same manner.

Abstract: Small changes in material properties of a work piece are detected by measuring small changes in elastic wave velocity and attenuation within a work piece. Active, repeatable source generate coda wave responses from a work piece, where the coda wave responses are temporally displaced. By analyzing progressive relative phase and amplitude changes between the coda wave responses as a function of elapsed time, accurate determinations of velocity and attenuation changes are made. Thus, a small change in velocity occurring within a sample region during the time periods between excitation origin times (herein called "doublets") will produce a relative delay that changes with elapsed time over some portion of the scattered waves. This trend of changing delay is easier to detect than an isolated delay based on a single arrival and provides a direct measure of elastic wave velocity changes arising from changed material properties of the work piece.

Abstract: The device includes a stand, a rail for supporting the wheel fixed to a horizontal part of the stand, longitudinal guide members fixed to a vertical part of the stand and extending in a direction parallel to the rail, slideways fixed to the horizontal part of the stand and extending in a direction parallel to the rail, and a carriage movable along the slideways. The carriage carries a grinding device and a hardness measuring device. Means permit applying a force on the hardness measuring device. An ultrasonic inspection device carried by the carriage may also be provided.

Abstract: The wheel rests upon a rail. A chassis mounted on a lifting and supporting mechanism carries slides arranged on either side of the rail and parallel to the rail. Two carriages are mounted to move translationally on the slides. Grinding devices, an ultrasound checking device and two position detectors are mounted on the carriages to move translationally in a direction perpendicular to the slides. The propagation time for the ultrasound in the rim is measured in two perpendicular directions and the width of the rim is measured. The propagation speeds of the ultrasound are calculated and compared so as to determine the stressed state of the rim.

Abstract: Increasing use of thermo-mechanically treated high strength steels in construction projects has created a need for on-site inspection of welded joints by ultrasonic techniques. However, such steels are acoustically anisotropic, and corrections of test results for anisotropy, according to the traditional methodologies, require lengthy and complex preparation steps which are unsuitable for on-site testing. The present invention presents an automated quick and simple methodology, and a compact apparatus for determining the acoustic anisotropy in such materials. The apparatus is expected to lead to effective management of quality assurance not only in civil and architectural engineering projects but in heavy machinery and ship building industries.

Abstract: Test apparatus (10) performs non-destructive testing of an object (O) to determine if it has flaws or defects. An ultrasonic wave (W) is generated and directed at the object. A return wave (R) reflected by the object is received and analyzed to determine if a flaw or defect. The return wave is converted to digital data which is stored for purposes of later analysis. For this purpose, digital signals containing the data are routed over a quiet bus (24). Digital signals are routed over the bus prior to generation of an ultrasonic wave to establish test parameters. Digital noise may occur during the transmission. A controller (22) controls routing of digital signals over the bus. The controller inhibits the flow of digital signals over the bus during that portion of an operational cycle of the apparatus during which the ultrasonic waves are produced and return waves evaluated. The controller allows transmission of digital signals over the bus at other times.

Abstract: A method and system for nondestructively testing in a continuous sequence a multiplicity of railroad track crossties of wood or concrete to determine the condition and life expectancy of each of the crossties and of the track as a whole. The system includes an electric pulse generator and a pair of transmitting and receiving transducers, which transducers are adapted to be brought into moving contact with the crossties at respective locations straddling desired test regions thereof, for example, the regions under a tie plate, for sending sonic mechanical pulses through that region of the crosstie from one transducer to the other. If desired, three pairs of transducers may be provided for simultaneously straddling both tie plates and a medial reference zone on each crosstie. The transducers and the pulse generator are carried by a vehicle riding on the track rails, along with a computer for processing/evaluating/storing/reproducing the test data.

Abstract: Method and apparatus are described for using stress wave measurements in the estimation of quality of finger joints in wood and quality of lumber, where quality is typically defined as strength. Application and measurement of stress waves in the transverse direction of the material allows localized measurements to be made, and features developed from this information are used in the quality estimation. A feature is a quantifiable characteristic developed from stress wave signals which can be used either by itself or in combination with other features to estimate quality. Examples of features include the propagation velocity of a stress wave, the attenuation of a stress wave, the difference in stress wave propagation times measured at different locations along the lumber, and the effects on amplitude and phase of frequency components of a stress wave. Treating features together as a feature vector and as input to an estimator function, estimated quality can be evaluated.

Abstract: A method for the detection and evaluation of faults existing on the walls of metal tubes having internal helical ribs includes for each fault signal received by an ultrasonic emitter-receiver ER, the length of the to-and-fro travel completed by the ultrasonic beam corresponding to the signal is determined and after the amplitude of the signal has been compared with a specific threshold, a correction is applied to one of the terms of the comparison, taking into account the length of travel completed by the signal.

Abstract: A non-destructive method for determining the presence of anisotropic structures in the interior of an as-formed metal. The method includes the steps of (a) attaching an ultrasonic transducer to the metal item prior to working the metal; (b) energizing the transducer to generate shear ultrasonic waves capable of penetrating the metal item; (c) measuring the time of flight of the shear ultrasonic waves through the metal item; (d) rotating the transducer approximately 90.degree.; (e) repeating step (c); and determining the difference between steps (c) and (e) to determine the presence of anisotropic structures in the interior of the metal item.

Abstract: The invention is a method and apparatus for characterizing residual uniaxial stress in a ferromagnetic test member by distinguishing between residual stresses resulting from positive (tension) forces and negative (compression) forces by using the distinct and known magnetoacoustic (MAC) and a novel magnetoacoustic emission (MAE) measurement circuit means. A switch permits the selective operation of the respective circuit means.

Abstract: Apparatus for determining, through an interposed medium, the mechanical properties of a solid. The apparatus includes ultrasonic transmission apparatus for transmitting an ultrasonic wave through the interposed medium and the solid, wherein the solid has a surface, at least first and second ultrasonic receiver units, for receiving the ultrasonic wave, and apparatus for locating the receiver units such that a first receipt time of the ultrasonic wave from the surface to the first receiver unit is generally equivalent to a second receipt time from the surface to the second receiver unit.

Abstract: An ultrasonic tip diffraction technique for determining the depth of a surface-opening crack is disclosed. Longitudinal ultrasonic waves are transmitted parallel to and along the crack and measurement of the time of travel of the waves diffracted at the tip of the crack is employed to determine the depth of the crack.

Abstract: In devices for the ultrasonic testing of a head screw inserted into a component, a skew position of an ultrasonic probe with respect to the screw head leads to inaccurate test results. In order to achieve precise test results independently of the position of the screwing-in axis, at least one ultrasonic transducer is disposed in a cradle-mounted centering piece of the ultrasonic probe. An adaptor of the centering piece is located nearer to the screw head than the ultrasonic transducer. The adaptor is matched to the configuration of the screw head. In order to achieve a centering connection with the screw head, the ultrasonic probe can be moved about its axis and in the axial direction. The device is principally to be used to test screws in the core baffle of a nuclear reactor vessel.

Abstract: An in situ method is disclosed for determining the structural integrity, set time and locations of anomalies or voids within a material as the material is being cured. Surface waves are transmitted and received a known distance along the surface of the material so that a substantially constant surface wave velocity can be calculated by dividing the known distance by the time it takes for the surface waves to travel the known distance. Surface wave velocity remains substantially constant for all wavelength measurements which do not exceed the thickness of the material. Structural integrity of the material, set time of the curing material and the detection of voids within the material can be determined from the substantially constant surface wave velocity. Structural integrity is determined as being proportional to the substantially constant surface wave velocity.

Abstract: A log analysis method can be used to determine a relative condition of a lined casing within a geothermal well from logged instrument data. Uncertain conditions, such as an unknown scale layer thickness, may perturb the indicators of a casing condition within the logged signals. The method can be used to detect the perturbed signals, discern a perturbed reference interfacial indicator in the data, searches for an adjacent interfacial indicator within a window, and axially aligns the adjacent indicator by shifting the data signal towards the reference indicator. The baseline indicator may be an arbitrarily selected signal indicator or a prior (non-scaled/non-eroded) condition indicator. A prior condition indicator can also be used to determine a second window for detecting an adjacent surface signal indicators.

Abstract: A method and apparatus is reported for detecting inhomogeneities in semi-plastic substances such as toilet bars containing soap. An ultrasound probe is utilized to test the substance at an exit orifice of an extruder. Best results are obtained by utilizing a ceramic ultrasonic probe, rectangular in shape including a transducer having a concave curvature on a lower surface thereof. The probe includes a theromplastic delay material. Ultrasonic waves directed through the probe preferably have a frequency between 1 and 2.25 MHz. Wedging of the extruded substance is also useful to improve contact with the probe as it passes through the extruder exit orifice.

Abstract: An immersion type automatic ultrasonic testing apparatus for detecting flaws of balls comprising a tank for containing a liquid medium of transmitting ultrasonic wave, a ball rotating device for rotating a ball to be tested, an ultrasonic flaws detection device for detecting surface flaws in the ball while swiveling a probe around the ball rotated by the ball rotating device or rotating the ball spirally by the ball rotating device with or without swiveling the probe, and a ball feeding device for feeding the ball to the position of the ball rotating device. The ball feeding device comprises an air cylinder for holding the ball by suction at the tip thereof. For the suction holding of the ball at the tip of the air cylinder, a level regulating device is additionally provided for setting a level of the liquid medium of transmitting ultrasonic wave in the tank wherein the ball rotating device and the ultrasonic flaws detection device are placed.

Abstract: An ultrasonic air-in-line detection system for use in detecting air bubbles in the fluid line of a disposable cassette mounted on a main pump unit is disclosed in which a self-test procedure is periodically used to ensure that any faults in the ultrasonic air-in-line detector which do not fail safe are automatically detected. After a pumping cycle is completed, if the ultrasonic air-in-line detector indicates that there is fluid in the fluid line at the location of the ultrasonic sensor, the operating frequency of the transmitting ultrasonic transducer is changed to a non-resonant frequency for the self-test procedure. If the ultrasonic air-in-line detector still produces a signal indicating that there is fluid in the line, this indicates that there is a failure in the ultrasonic detector and a fault is indicated and the system is shut down.

Abstract: Fluid leakage from a crack or other leakage point and other vibration-generating events in pipes and conduits may be located and analyzed by sensing axial and torsional vibrations and pressure fluctuations created by such events by placing accelerometers and/or strain gauges and pressure sensors on the conduit at selected points. The location of the event may be determined by comparing the travel time of selected pairs of signals such as axial propagated signals as compared with torsional propagated signals as a result in the difference of the acoustic wave speed of axial versus torsional waves. Cross correlation and deconvolution processes are carried out on the measured signals to determine differential signal arrival times at the sensors and to eliminate pipe response signals.

Abstract: A method is disclosed for ultrasonically detecting creep swelling in tubular members such as fossil utility steam lines and headers. Ultrasonic surface waves (34) are propagated around the pipe (10) in a circumferential direction. The transit time (.DELTA.T) is measured by using the pulse overlap technique with an oscilloscope (24). Circumferential dimension is obtained by multiplying the transit time (.DELTA.T) by the known Raleigh velocity of sound in the tubular member.

Abstract: A method and apparatus for nondestructively determining fiber volume fraction and resin porosity of a composite material constructed of at least two different constituent materials wherein the following parameters of the composite material to be tested are known: density, elastic moduli of the constituent materials and layup sequence. Two acoustic waves of different polarizations are propagated through the composite material and the acoustic waves propagated through the composite material are sensed and the velocity of each of the two acoustic waves, V.sub.1 and V.sub.2, are determined. The thickness of the composite material is determined. The fiber volume fraction and resin porosity of the composite material are then determined using the velocities, V.sub.1 and V.sub.2, the thickness and known parameters of density, elastic moduli of the constituent materials and layup sequence.

Abstract: An apparatus for inspecting a pipeline having a pig body which measures an inner shape and a wall thickness of a pipe body, travelling inside the pipe body, comprises: at least one distance measuring device for measuring a travelling distance of the pig body; a rotation angle gauge for measuring a rotation angle of the pig body round its center axis; a plurality of transducers for transmitting and receiving ultrasonic beams being arranged in the circumferential direction of the pig body and being confronted with the inner surface of the pipe body, which measures the inner shape and the wall thickness of the pipe body; a recorder of the pig body which stores measured data; a signal processing device for processing signals from the distance measuring device, the rotation angle gauge and the transducers; and a data processing device for analyzing the measured data stored in the recorder after the pig body has been taken out of the pipe body.

Abstract: An acoustic transducer having a curved surface to match the inner or outer surfaces of a target surface such as a cylindrical borehole tubular is disclosed. A sequence of excitation pulses causes the transducer to launch a series of high-frequency, short duration acoustic energy pulses toward the tubular. The transducer face receives echos reflected from the surface of the tubular, including multiple echo structures indicative of the repeated echoing of the acoustic energy between the inner and outer faces of the tubular. The characteristics of the tubular surfaces, including the location, area and depth of any corrosion pits on the tubular surfaces, are determined from the full echo waveform. A rule-based Expert System analyzes the full waveform of the echo pulses returned from the tubular to determine the most likely characteristics of the surfaces which produced the full echo waveform.

Abstract: Valve spring assemblies are checked for proper assembly of keys by ultrasonically scanning a plurality of assemblies along a path crossing the stem, keys and cap to acquire profile data; compensating for temperature effects by determining the average time of flight to the stems, which are nominally the same distance from the ultrasonic sensor, and searching for each individual stem in a window centered on the average time of flight; then defining windows for the keys and cap offset from the measured surface of each stem; and searching the data for points within the respective windows to determine proper positioning of each element. The apparatus includes ultrasonic equipment, a scanning manipulator to move the ultrasonic sensor over the part, and a computer interfaced to the ultrasonic equipment and manipulator for control and data analysis.

Abstract: The present invention provides an ultrasonic method for measuring the size of a possible flaw in a solid mass, in which an ultrasound is transmitted perpendicularly to the searching surface of a solid mass being the object under measurement through a liquid, a ratio in sound pressure between a reflected wave of the ultrasound from the surface of the solid mass and a reflected wave from any flaw in the solid, and a distance from the surface of the solid mass to the flaw, derived from the difference in time of reception between the reflected wave from the surface of the solid mass and the reflected wave from the flaw in the solid mass, are taken as indices of evaluation, and these indices of evaluation are compared with a reference value obtained beforehand by measuring a test piece made of a same material as that of the solid mass, thereby determining the size of the flaw.

Abstract: A computer-based defect recognition system for the automatic detection of parts defects includes an inspection knowledge base which enables automated defect inspections based upon a variety of nondestructive imaging tests, particular parts under test, the particular zone and region of the part, and the types of nondestructive imaging tests used. The knowledge database also provides for automated defect recognition to be applied to a wide variety of parts using a variety of nondestructive imaging tests while enabling flexible testing of different classified zones and regions of each part using the part-specific, zone- or region-specific, imaging test-specific inspection criteria, image processing algorithms, and computation algorithms.

Abstract: In the field of the echography, the present invention is a system and method of preprocessing and transmitting information (such as echo waveform information) from a source (such as a transducer) to a destination (such as a rule-based computer system). The present invention reduces the absolute amount of information that is transmitted without reducing the amount of meaningful information that is conveyed. In this way, the present invention is effectively able to transmit more meaningful information than would be expected for conventional transmission systems. It also acts to reduce the amount of information processing that must be done at the destination.

Abstract: A sample is cut from the upper region of a continuously cast ingot and rolled to compact the impurity band in a direction that was horizontal during casting.

Abstract: The subject of the invention is a method and a device for detecting faults in or on an object. The object form is measured and then compared with a master form. In this comparison one point and one line of the object form and of the master form with reference to a coordinate system, are brought into coincidence by shifting the form or master form. Partial forms and partial master forms are then displaced relative to one another in partial areas of the coordinate system until a maximum overlap is detected. Then the nonoverlapping points of the partial forms are checked for faults.

Abstract: An ultrasonic flaw detector comprises channels for transmitting and receiving electrical signals. The transmission channel comprises a sync pulse generator (1) connected to a sonic pulse generator (2) and transmitting piezoelectric elements (3). The receiving channel comprises receiving piezoelectric elements (4), a radio-frequency pulse amplifier (6), a video detector (7), a control voltage generator (15), and horizontal-sweep and vertical-sweep generators (16 and 15) which are connected to a frequency divider (13). The output of the video amplifier (8) is connected to a multivibrator (10). The receiving channel also comprises three electronic switches (11, 12, and 5).

Abstract: An ultrasonic inspection probe for locating and sizing flaws in the radius region (20) and adjacent areas of a laminated structure (10), such as a composite "T" stiffener (30). The probe includes a plurality of shoes (48, 50, 52, 54, 56, 58) that are arranged for coordinated movement relative to the part under inspection. Each shoe includes a plurality of ultrasonic transducers that are arranged in predetermined adjacent relationships to one another and operated in timed sequence in one or more through-transmission, pulse echo or loss-of-back modes to effect an ultrasonic scan in one direction through the part while the transducers are moved together in another direction along the part. Inspection of the radius region is effected using combinations of angular pulse echo inspection (PEF, PEA, LL45P, RL45P), "radius-to-radius" through-transmission inspection at an angle through the radius region (RTT, RTR, L37.5T, L37.5R, U37.5T, U37.

Abstract: A mechanically amplified electroacoustic transducer system comprising an electroacoustic transducer having a vibrating element and an amplifier rod forming a probe extending from the transducer and in acoustically coupling contact with the vibrating element over a relatively small region thereof. The probe has a length which is approximately equal to the quarter wavelength or a multiple of the quarter wavelength of the acoustical energy generated by the transducer, the exact length of the probe being selected to provide optimum output from the system at a selected operation frequency of the transducer.

Abstract: A method of measuring the depth of a microcrack. A sample which has a crack substantially parallel to the surface and slightly inclined is set in the neighborhood of the focal point of a converging acoustic beam, and the depth of a microcrack of the sample irradiated with the beam is measured on the basis of the phenomenon that the reflected wave intensity assumes a minimum value when the product of the crack depth and the frequency of the acoustic wave is equal to a half integral multiple of the velocity of the acoustic waves in the sample.

Abstract: A multi-viewing ultrasound transducer acquisition system for non-destructive evaluation, flaw detection and flaw reconstruction in materials. A multiple transducer assembly includes a central transducer surrounded by a plurality of perimeter transducers, each perimeter transducer having an axis of transmission which can be angularly oriented with respect to the axis of transmission of the central transducer to intersect the axis of transmission of the central transducer. A control apparatus automatically and remotely positions the transducer assembly with respect to the material by a positioning apparatus and adjusts the peGRANT REFERENCEThis invention was conceived and reduced to practice at least in part under a grant from the Department of Energy under Contract No. W-7407-ENG-82.

Abstract: A method for measuring lattice defects in semiconductor such as a silicon crystal, detects an ultrasonic velocity of an ultrasonic pulse propagating through the semiconductor to which heat is variably applied. An elastic constant of the semiconductor is calculated from the ultrasonic velocity, and a concentration or density of lattice defects of the semiconductor is obtained by converting the elastic constant.

Abstract: The subject of the invention is a method and device for non-destructive testing of electrically conducting objects (10) by means of penetrating ultra-sonic waves, whereby the ultra-sonics signals are electro-dynamically generated. While being tested the object is located in a magnetic field. The probes (30, 32) arranged on diametrically opposite sides of the object (10) are set at the smallest possible constantly maintained distance from the surface. The signals used for detecting the flaw are corrected so that any variations in the thickness of the object (10) in the area of the probes (30, 32) are taken into account.

Abstract: A system is provided for measuring the velocity of vibrations in a moving web, such as a sheet of paper. The system includes a transmitter coupled to the paper to transmit waves and a receiver to receive the waves. A signal processing system is used to determine the velocity.

Abstract: A method and device for determining the internal structure of the body by means of ultrasound beams from transit time measurement. An iterative solution of integral equations is used to calculate the actual path which the ultrasound beams follow through the object.

Abstract: An non-destructive testing method employs an ultrasound generator which provides a beam having an axis which intersects the outer surface of an object to be tested at an angle relative to a line normal to the surface which is in the range of 23.degree. to 28.degree.. A longitudinal mode wave and a shear mode wave are propogated within the object and the shear wave is converted into longitudinal mode waves by reflection from an opposite surface of the object. The propogated and mode converted waves are reflected from different portions of a defect and the echos arrive serially in time at a receiver transducer. The ultrasound generator and receiver transducer are sonically isolated. The received signals have a favorable signal-to-noise ratio and the times of receipt thereof are employed to determine the dimensions of a detected defect.

Abstract: The invention relates to an ultrasonic test instrument for the nondestructive testing of materials. The instrument includes a transit time measuring circuit and an amplitude and time gate circuit. According to the invention, to measure the amplitudes and the corresponding transit times of a number of echo signals falling within a predetermined measurement range, the output of the amplitude and time gate circuit is connected to the input of a presettable counter which outputs a signal whenever the number of counted pulses is equal to the preset value of the counter. The counter output is connected to the transit time measuring circuit and by way of a second time gate circuit to the amplitude measuring circuit so that amplitude evaluation is carried out only during the time interval defined by the second time gate circuit.

Abstract: In a method and apparatus for ultrasonic measurement, there are provided first and second ultrasonic transducers arranged to directly oppose each other across an object interposed therebetween, and a third ultrasonic transducer, the transducers being so arranged that a ray from the third ultrasonic transducer intersects, internally of the object, a ray connecting the first and second ultrasonic transducers. A first period of time required for an ultrasonic wave emitted by the first ultrasonic transducer to be received by the second ultrasonic transducer through the object is measured, as well as second and third periods of time respectively required for an ultrasonic wave emitted by the third ultrasonic transducer to be received by the first and second ultrasonic transducers following scattering of the ultrasonic wave from within the object.

Abstract: The non-destructive testing of solid bodies is conducted by generating a transverse, ultrasonic surface wave in the solid body being inspected, said surface waves having sufficient different frequencies such that they travel at different depths through the body being inspected; receiving at least a part of the reflected portion, if any, of the surface waves, the reflected portion consisting of at least two surface waves having sufficiently different frequencies such that these waves travelled at distinctly different depths through the solid body and filtering and measuring or analyzing the reflected portion of the surface waves to determine if a defect or discontinuity exists in the solid body and the depth or severity of the defect or discontinuity.

Abstract: A method and apparatus of detecting fractures along the wall of a formation, such as a well formed by test-drilling, provides for the transmission of ultrasonic signals in a direction essentially perpendicular to the wall from a position spaced from the wall by a predetermined distance and the reception of the ultrasonic signals which may be reflected by the wall. The space of predetermined thickness between the transducer which generates the ultrasonic signals and the wall is filled with an intermediate material which does not form a distinct interface with the wall of the type which would be able to produce an appreciable parasitic reflection of the transmitted signals.

Abstract: A method of automatically controlling the production of a weld bead including examining with reflected ultrasound from one surface of a piece of material the position of a weld pool on the material and the position of another surface of the material, and controlling the position of the weld bead on the material from the result of said examination.

Abstract: The invention relates to a method of suppressing unwanted indications in automated ultrasonic testing of a test piece.In order to improve the suppression of unwanted indications, in particular in the case of extended statistical suppression, a variable discriminator threshold (3) is derived from the highest of all maximum amplitudes (2) by means of a predetermined amplitude difference (4), wherein the ultrasonic signals are not evaluated as flaw signals when only said variable discriminator threshold (3) is exceeded but are evaluated as flaw signals only when additionally at least the highest of all maximum amplitudes (2) exceeds the fixed discriminator threshold (1) preset for the testing operation.