Abstract: A plurality of ultrasonic transducer elements are arranged on the top surface of a probe, which is a concave spherical surface, so that ultrasonic beams transmitted from the ultrasonic transducer elements will intersect at a point coincident with the center of curvature of a curve delineated by the top surface. At this time, the acoustic lines conically propagate over a region beyond the point of intersection. Namely, the ultrasonic beams transmitted from the ultrasonic transducer elements pass through the point of intersection coincident with the center of curvature, and then conically and three-dimensionally propagate over the region beyond the point of intersection. Thus, acoustic lines are three-dimensionally transmitted to a wide region beyond an intercostal part of a physiological body or any other narrow space, and echoes returned from the region are received. Consequently, the wide region can be three-dimensionally monitored.

Abstract: An apparatus and method are disclosed wherein a linear array of electromagnetic radiation emitting devices are arranged in association with a moving workpiece. Electromagnetic radiation emitted by the array is received by two or more receivers. Several non-contact measurements may be obtained on a workpiece using the present apparatus and methods.

Abstract: The bonding of an elastomeric cover to a metal roll is tested by transmitting audible frequency waves through the compliant roll cover and receiving the waves at a transducer mounted to the underlying steel roll. The resulting signal may be analyzed by a technician listing to the audio frequencies transmitted. The audio range of frequencies employed may be about 5000 Hz. The elastomeric material such as rubber does not transmit sound without considerable loss of amplitude, whereas sound travels at high speed through steel with little attenuation. A sound transmitter is spirally scanned along the rubber-covered surface of the roll, transmitting into the steel roll directly beneath the sound transmitter and throughout the roll. Sound is detected at a transducer mounted at the roll ends. Any failure or significant variation in the roll/cover bond is detected by the effect on the quality of sound transmitted through the rubber steel interface.

Abstract: The present invention provides an acoustical microscope which has a plurality of acoustical transducers, each generating an independent beam of acoustic energy. Each acoustical transducer is positioned in an adjacent relationship with the others such that each beam of acoustic energy intersects a different point on a target.

Abstract: Ultrasonic techniques are applied to the measurement of wooden members to identify splits in wooden members. Multiple angularly displaced measurements allow detection of splits at arbitrary angles.

Abstract: The exact spring height as well as the spring pressure can be determined with a single arrangement for the optimal utilization of the axle loads of a multi-axle air spring suspended vehicle and to control the distance between the chassis and the axle. An air spring (2) is equipped with an ultrasonic pulse/echo measuring system. The air spring (2) includes a transmitter/receiver component (14) arranged on the chassis and a first reference electrode (20) and a reflector component (16) fixed to the axle. The air spring height can be determined in a conventional manner from the relative value of the running times of the ultrasonic pulses which are traversed on the reference path and the measuring path. A second reference reflector (22) is mounted at a different distance to the first reference reflector (20).

Abstract: The invention is directed to an arrangement for making contactless distance and pressure measurements within an air spring. With a single arrangement, the exact elevation of the spring as well as the spring pressure can be determined. This permits optimal utilization of the axle loads of a multi-axle vehicle and permits adjustment of the distance between the chassis and the axle. In the arrangement, an ultrasonic configuration makes contactless distance measurements in accordance with the pulse/echo method. The arrangement includes a transmitter/receiver component (4) mounted on the chassis and a first reflector (24) defining a first reference distance (16) therebetween. The component (4) and a reflector (6) define a measuring distance (30). The reflector (6) is fixedly mounted to the axle. The transmitter/receiver component (4) is elastically supported by a suspension (10) in a pipe stub (8) fixedly mounted to the chassis.

Abstract: Method and apparatus for ultrasound testing of disc bodies which are shrunk onto shafts and have an unknown contour.The invention relates to a method and an apparatus for ultrasound testing of a disc body (2), which is shrunk onto a shaft (1), in the region of the shrink seating (3) and of the adjacent shrinkage influence zone, the disc body (2) having side pieces (4, 5) which taper radially outwards from the shrink seating in cross-section. The contour of the disc body (2) is scanned and its geometry is derived in this way. A geometric reflection surface is determined. Test parameters and test positions are determined from the disc body geometry in accordance with a predetermined test technique, and ultrasound test heads (9, 10) are coupled, using the determined test parameters, to the side pieces (4, 5) in order to cover the determined test paths. The associated apparatus has a geometry identification device which detects the geometry of the disc body (2) before the actual test procedure.

Abstract: An ultrasonic imaging system for imaging an object. The system includes a mechanism for designating an ultrasonic probe swiveling angle threshold beyond which the ultrasonic probe does not adequately image the scanned object, and an echo amplitude correction apparatus for correcting the amplitude of a received echo by normalizing such amplitude to the value of a previously recorded echo of higher amplitude. Furthermore, the system includes a mechanism for monitoring acoustic coupling, which includes a low frequency noise level selection apparatus for manually selecting the power at which a low frequency reference noise is generated by a vibrator, and a low frequency noise receiving crystal located in the probe holder of the ultrasonic probe, for receiving the low frequency reference noise signal.

Abstract: The invention is directed to an arrangement for making contactless distance measurements within an air spring of a motor vehicle. With the invention, it is unnecessary to modify the longitudinal support of the motor vehicle for the purpose of integrating an ultrasonic distance measuring device. The arrangement includes a transmitter/receiver component (16) which is fixedly mounted to the chassis and is mounted within the air spring (2) laterally next to the support (10) of the vehicle, that is, the transmitter/receiver component is mounted elastically off-center in a tubular stub (14) arranged as part of the cover plate (4). A reflector component (24) is fixedly mounted on the axle and assigned to the transmitter/receiver component (16). The reflector component (24) is mounted on the roll-off piston (8) and includes a lens-shaped convex surface (26) having a surface normal (28) directed toward the transmitter/receiver component (16).

Abstract: An apparatus and method are disclosed wherein a linear array of electromagnetic radiation emitting devices are arranged in association with a moving workpiece. Electromagnetic radiation emitted by the array is received by two or more receivers. Several non-contact measurements may be obtained on a workpiece using the present apparatus and methods.

Abstract: A system for assaying a fluid sample for one or more types of analytes, which employs at least one class of finely divided polystyrene spheroidal particles, each class being limited to a predetermined specific narrow range of particle diameters, the particles of each such class being coated with a specific reactant unique for that class. After the coated particles are mixed with the sample to specifically react to form conjugates of the particles and any of the analyte present, the mixture is irradiated with bursts of ultrasound swept over a range of frequencies resonant to the expected conjugate sizes. The presence of the conjugates and therefore the analyte is detected directly by measuring any selective absorption or scattering of waves of frequencies to which the conjugates are resonant.

Abstract: An apparatus and method are disclosed wherein a linear array of electromagnetic radiation emitting devices are arranged in association with a moving workpiece. Electromagnetic radiation emitted by the array is received by two or more receivers. Several non-contact measurements may be obtained on a workpiece using the present apparatus and methods.

Abstract: A flaw detection method and arrangement utilizes electromagnetic acoustic transducers (EMATs) which ultrasonically test a material for cracks or flaws. Four EMATs are used in a pitch-catch configuration, i.e. two pairs of EMAT transmitters and receivers. The EMAT transmitters and receivers are arranged such that a first EMAT transmitter is located on the surface diagonally across from a first EMAT receiver and a second EMAT transmitter is located diagonally across from a second EMAT receiver. The first and second EMAT transmitters transmit ultrasonic signals to the first and second EMAT receivers respectively; and these ultrasonic signals are transmitted orthogonal to each other. A pulser/receiver is operatively connected to the first and second EMAT transmitters and the first and second EMAT receivers for inducing the EMAT transmitters to propagate their respective waves. The pulser/receiver also receives the signal transmitted through the material after being received by the first and second EMAT receivers.

Abstract: A method and apparatus for non-destructive ultrasonic inspection in which a plurality of integrated circuits or other electronic components laid out in a fixed pattern on a liquid-permeable tray are moved along an inspection path through a scanning station. In the scanning station the electronic components are repetitively scanned by an ultrasonic beam from a transmitter/receiver moving rapidly back and forth across the inspection path; an ultrasonic coupling liquid (usually water) continuously flows along the beam path; the coupling liquid also flows along the surfaces of the electronic components opposite the beam path. The tray of electronic components is air dried as it emerges from the scanning station. Both reflected and "through" ultrasonic signals can be collected to disclose any anomalies present in the electronic components. A screen may be used to assure retention of the electronic components in the desired pattern on a tray.

Abstract: An ultrasonic method and system are provided for monitoring a fabric to identify a defect. A plurality of ultrasonic transmitters generate ultrasonic waves relative to the fabric. An ultrasonic receiver means responsive to the generated ultrasonic waves from the transmitters receives ultrasonic waves coupled through the fabric and generates a signal. An integrated peak value of the generated signal is applied to a digital signal processor and is digitized. The digitized signal is processed to identify a defect in the fabric. The digitized signal processing includes a median value filtering step to filter out high frequency noise. Then a mean value and standard deviation of the median value filtered signal is calculated. The calculated mean value and standard deviation are compared with predetermined threshold values to identify a defect in the fabric.

Abstract: A acoustical imaging scanning head includes a roller driven optical encoder. The encoder and its shaft are isolated in a non-magnetic housing. The encoder shaft and a roller driven drive shaft are provided with permanent magnets on facing steel discs on opposite sides of a relatively thin wall of a non-magnetic housing. The encoder is sealed in a chamber in such housing and is totally isolated from the surrounding environment, including the drive shaft. The position and arrangement of the magnets maintains the ability to rotate the encoder shaft to produce electrical pulses proportional to the encoder shaft rotation.

Abstract: A mechanical contour follower is disclosed for maintaining a transducer ninety degrees to a workpiece surface, with respect to longitudinal and transverse axes of the workpiece surface, and for keeping the transducer at a constant distance from the workpiece surface during an ultrasound inspection of the workpiece (these conditions being referred to as keeping the transducer normal to the workpiece surface).

Abstract: In accordance with the present invention there is presented an automated system for testing the ability of clinical ultrasound scanners to detect focal lesions in human tissue. An ultrasound scanner phantom containing background material mimicking the ultrasonic characteristics of human tissue and coplanar spherical target lesions ultrasonically contrasting with the background material is scanned using the ultrasound scanner to be tested. Digitized images are made of the ultrasound scan of slices in the ultrasound phantom containing background material only and of slices on which the focal lesions are centered. A lesion signal to noise ratio (SNR).sub.L is then calculated at each defined pixel coordinate in the target lesion slice.

Abstract: An apparatus and method are disclosed wherein a linear array of electromagnetic radiation emitting devices are arranged in association with a moving workpiece. Electromagnetic radiation emitted by the array is received by two or more receivers. Several non-contact measurements may be obtained on a workpiece using the present apparatus and methods.

Abstract: To improve and simply ultrasonic measurement of thin layers, an adaptive least-mean-square (LMS) implementation of a Wiener filter is used to deconvolve ultrasonic waveforms. This filter is structured as a finite-impulse-response (FIR) filter and solved using Widrow's adaptive linear combiner. The filter is implemented on a microcomputer with gating features for automated signal peak identification and measurement. The deconvolution process begins by assuming an impulse (the desired response) to a known input (the ultrasonic response). A transfer function is then determined that, when convolved with the response, results in the assumed impulse. The transfer function in this case is a long FIR filter typically requiring up to 128 taps to achieve acceptable results.

Abstract: The method for ultrasonic testing of work pieces to detect longitudinal, transverse and oblique errors therein uses a test head support having at least one test head. The test head support is moved in a translatory direction along a surface of the work piece. Ultrasonic impulses are generated in a rapid sequence by the test head, progress along a sound beam, and are directed to impact the surface of the work piece in test areas. All test areas of the at least one test head lie in a linear test path. In the case of uninterrupted, translatory movement, all test areas meet in one and the same test area. The sound beams progress in a given constant angle in relation to one set perpendicular line on each test area. The sound beams rotate, in a conical envelope, around the respective perpendicular line. A complete rotation of 360.degree. takes place in time t.sub.r which is shorter than time t.sub.

Abstract: A scanning range of an object under examination is divided into m pieces (m is an integer equal to or more than 2) in a subscanning direction. One measurement condition or one parameter is set in m steps, and an ultrasonic measurement is performed on the object under examination while allotting successively the m-stepped measurement conditions or the m-stepped parameters to the respective scanning regions divided in the subscanning direction. A plurality of measurement images obtained under the m-stepped measurement conditions are displayed so as to permit comparison on a screen, and one of the m-stepped measurement conditions or m-stepped parameters which corresponds to an image selected from the displayed screen is set as the measurement condition.

Abstract: A system for finish machining an in-process part having an inaccessible interior cavity, an envelope of excess material to be machined, and a predefined minimum wall thickness includes a fixture for holding the in-process part to be finish machined. Also included is a co-ordinate measuring machine having a ball probe for measuring external co-ordinates of the in-process part and also having a sonic thickness probe for measuring wall thickness of the in-process part at various selected points on the part. A programmed digital computer is operably connected to the co-ordinate measuring machine to receive data regarding the measurements made. Stored in the computer is a model of the part which is to be machined and minimum wall thickness requirements at various points on the part. The computer is further programmed to calculate the optimal position of the final part in relation to its interior cavity such that wall thickness requirements are maximally satisfied over the total part surface.

Abstract: A scanning tunneling microscope, in which the gap between a tip having a keenly sharpened end and a sample is narrowed to let flow a tunneling current between them and thereby allow observation of the surface of the sample, a strain wave detecting device is disposed on the sample or in the vicinity of the sample to detect strain waves generated within the sample. By modulating the value of the above described tunneling current, strain waves are generated within the sample. The strain waves are detected by the above described strain wave detecting device. On the basis of the amplitude information and phase information of detected strain waves, physical information regarding the inside of the sample is obtained.

Abstract: An instrument for measuring the properties of materials. This nondestructive, noncontacting instrument detects electromagnetic radiation from the materials across a wide range of the electromagnetic spectrum, and combines these diverse data so as to derive the material property values desired. In particular, the properties detectable through particle magnetic resonance, spectroscopy of light in the infrared-visible-ultraviolet range, and detection of x-ray and gamma ray radiation may be included in the instrument. Sensors detect each wavelength band of electromagnetic radiation, and data from all of these sensors is merged in a central data processor to evaluate the material properties of interest.

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 scanning tunneling microscope, in which the gap between a tip having a keenly sharpened end and a sample is narrowed to let flow a tunneling current between them and thereby allow observation of the surface of the sample. A strain wave device is disposed on the sample or in the vicinity of the sample to detect strain waves generated within the sample. By modulating the value of the above described tunneling current, strain waves are generated within the sample. The strain waves are detected by the above described strain wave detecting device. On the basis of the amplitude information and phase information of detected strain waves, physical information regarding the inside of the sample is obtained.

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 flaw detection device for detecting 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 and removing device for feeding the ball to the position of the ball rotating device and removing the tested ball from the ball rotating device to a predetermined position. The ball feeding device comprises a holding device having an air cylinder and a tip with a pair of holder claws and a pair of side support claws for holding the ball.

Abstract: A device for simulating a moving test object sensing transducer uses a plurality of individual transducers which are stationary relative to each other (for example eddy-current based surface transducers), and a selector unit. The individual transducers are, for example, mounted in a plane parallel to the surface of the test object to be sensed and scan the test object with respect to a characteristic, for example a crack. The resultant simulated transducer signal is signal processed by means of, for example, automatic compensation and vector transformation techniques.

Abstract: A method and apparatus for non-destructive ultrasonic testing of tires is disclosed wherein an ultrasonic transmitter is positioned outside of the tire and applies pulses of ultrasound to the tire at a plurality of locations around the tire's circumference for transmission through the tire wall and receipt by an ultrasonic receiver located within the tire. The ultrasonic receiver generates signals in response to the received ultrasonic transmissions and a computer processes these signals to generate characterizing data from which defects in the tire may be determined. Signals representative of the defects are then processed to generate a graphic display illustrating the location of the defects with the tire.

Abstract: A manipulator for a transducer detector for indication of cracks and the like in hot metallic blanks, has the transducer driven relative to the blank by means of a car, a slide or other transducer carrier, which is placed inside or near a tube extending in the required scanning direction relative to the blank and being raisable and lowerable relative to the blank.

Abstract: A portable ultrasonic inspection probe (400) for determining the presence, location, and size of flaws in a laminated structure such as a composite "I" stiffener (30'). The probe includes a shoe assembly (402) having a plurality of shoes (52', 54', 56', 58') that are arranged for coordinated movement relative to the "I" stiffener and house a plurality of ultrasonic transducers that produce inspection information related to the "I" stiffener. The shoes are biased by spring assemblies (64' and 66') toward the web 34' and flange 32' and flange 32' of the "I" stiffener. A fore drive (404) and an aft drive (406) are mounted on the shoe assembly and spring loaded to engage the "I" stiffener so as to cause translational movement of the shoe assembly when energized. The shoe assembly may be moved by either one or both of the drives. A position encoder (408) produces information related to the position of the probe as it is moved along the "I" stiffener.

Abstract: An automatic, electronically operated data collection and display system for a pipeline video monitoring device, and a method for collecting and displaying information on a pipeline with a video image. A plurality of data inputs are connected to the monitoring device for receiving information on the operating parameters of the device. The data inputs include an operator input. A control unit is connected to the data inputs and has an interconnected central processor, input/output control system, and graphics generation and video overlay system. Data outputs are connected to the input/output control.

Abstract: A therapeutic ultrasound hyperthermia system utilizes a phased array of ultrasound transducer elements. By varying the phase delays in the excitation of individual transducer elements, the focal depth of the ultrasonic beam can be varied, without changing the distance between the transducer and the patient. The phased array of transducer elements can be an array of rectangular elements which are rotated about an axis to deliver ultrasound to the target region while minimizing overall heating effect in the treatment areas outside the target region.

Abstract: An apparatus for inspecting a tire for structural defects as the tire is rotated on a stand comprises a movable transducer transmitter for directing a plurality of successive collimated bursts of ultrasonic energy against the tire surface, said bursts passing through the tire and forming inspection areas having the same diameter and overlapping each other as the tire is rotated during an inspection cycle. A movable receiver transducer located on the other side of the tire from the transmitter is constantly positioned to receive the collimated ultrasonic energy that passes through each inspection area. Coordination control elements are provided for moving the transmitter transducer and the receiver transducer from one side of the tire to the other generally parallel to its axis of rotation while successive ultrasonic bursts are directed through the tire as it rotates during each inspection test and while maintaining substantially the same distance between the transducers for each burst.

Abstract: A computerized system for the recording of flaw images by ultrasonic examination according to the pulse-echo method includes at least one ultrasonic probe which can be moved in steps over the surface of an object along a rectilinear scanning path. Digital signals containing information on the successive positions of the sound beam, on echo amplitudes, and on the lengths of sound paths to reflectors inside the object, are processed and used for the accumulated storage of circular patterns of echo amplitude data in a matrix memory associated with a sectional plane through the object. A video screen terminal controls the system and transforms the accumulated data into displays of sectional flaw images of greatly improved precision and sharpness of definition.

Abstract: A memory means is provided which is adapted to be mounted integral with the transducer element used in a transducer system. The memory may store nonlinearity error information or other information concerning errors in the positioning or scan control for the particular transducer, which information may be utilized by the transducer system to compensate for such errors. The memory may also be utilized to store selected information concerning the measured output characteristics of the transducer element which may be utilized by the transducer system to assure that a desired output level is achieved from the transducer element or that the output otherwise is in conformance with that desired. One or more bytes may be provided in the memory which may be utilized to inhibit use of the associated transducer element for particular fields of use or classes of service.

Abstract: The invention is a method for the on-line nondestructive determination of the internal bond strength of composite panel products. The method involves impinging an ultrasound pulse against the panel by a first transducer and receiving a transmitted pulse at a second transducer. The received signal strength, temperature and panel thickness are entered into an algorithm from which the internal bond may be calculated. Preferably the receiving transducer is located on the opposite side of the panel and displaced somewhat from the first transducer. The inclusion of temperature and panel thickness as independent variables greatly improves the accuracy over that available from uncorrected ultrasound testing.

Abstract: An ultrasonic imaging system which is used to provide contact imaging of a component. A transducer is scanned across a workpiece to collect image data from a scan area comprising a plurality of pixels. Means for resiliently carrying the transducer with two separate degrees of freedom maintain a tight acoustic coupling between the workpiece surface and the transducer. The image data relating to each position in the scanned area describe the amplitude of a reflection and its depth from a reference. Means are provided for easily varying the size of the image area while the number of pixels remains constant. The system provides a real-time visual display of the scanned area while the transducer is moving over the area in contrast as either a grey scale or a color scale for each pixel. An automatic calibration mode for the sytem is provided as another feature to remove acoustic delay, caused by transducer coupling, from the image data.

Abstract: An X-ray inspection system for manually or automatically performing digital fluoroscopy inspections and/or computed tomography inspections by X-ray examination of manufactured parts incorporates a computer system which automatically analyzes the inspected parts for flaws. The system includes apparatus for automatically positioning the parts in an X-ray machine for obtaining fluoroscopy and tomography views of the part and for acquiring data from the inspections at production rates. The system automatically identifies the location of rejectable flaws in the parts during the fluoroscopy scanning and subsequently identifies those locations for obtaining tomography scans, if the identified flaw location is questionable. The system can automatically reject parts containing flaws identified during the fluoroscopy inspections. This system operates in a real-time environment by providing analysis of one part while a subsequent part is being subjected to X-ray examination.

Abstract: A method of measuring the inclining angle of a planar defect of a solid material with ultrasonic waves which includes the steps of irradiating ultrasonic waves incident to the planar defect of a solid material while longitudinally scanning a probe forwardly and backwardly. The inclining angle of the planar defect is determined based on the inclination of an echo envelope obtained from the relationship of the echo beam path distances of the ultrasonic waves versus the echo amplitudes or heights of the reflected waves reflected from the planar defect of the solid material. The inclining angle of the defect corresponds to a straight line portion of the echo envelope in a region where the echo height decreased gradually from a maximum height position as the echo beam path distance increases.

Abstract: A supersonic flaw detecting system has a probe adapted to emit a supersonic wave towards an object to be inspected, a scanning device for causing a relative movement between the probe and the object in two orthogonal directions, a pulser-receiver adapted to supply pulses to the probe and receive the supersonic wave from the object and produce an electric signal indicative thereof, a signal processing device for converting the electric signal from the pulser-receiver into an image data signal for a C-scope display, an oscilloscope for conducting an A-scope display of the electric signal from the pulser-receiver, and a monitor T.V. having a screen for conducting the C-scope display of the image data signal from the signal processing device.

Abstract: The invention is a method for the on-line nondestructive determination of the internal bond strength of composite panel products. The method involves impinging an ultrasound pulse against the panel by a first transducer and receiving a transmitted pulse at a second transducer. The received signal strength, temperature and panel thickness are entered into an algorithm from which the internal bond may be calculated. Preferably the receiving transducer is located on the opposite side of the panel and displaced somewhat from the first transducer. The inclusion of temperature and panel thickness as independent variables greatly improves the accuracy over that available from uncorrected ultrasound testing.

Abstract: An ultrasonic flaw detecting system comprises a manual scanning unit equipped with a probe and capable of producing a probe position data signal, an ultrasonic flaw detector for transmitting an ultrasonic signal to the probe and producing flaw detection data on the basis of a reflection echo signal as received, and a data collecting/recording unit for receiving the flaw detection data from the ultrasonic flaw detector and the probe position data from the manual scanning unit to record both data on an external recording medium, wherein the scanning unit, the ultrasonic flaw detector and the data collecting/recording unit constitute a portable flaw detection data collecting apparatus. The data stored on the external recording medium can be loaded in a data processing apparatus installed at a predetermined location independent of the portable flaw detection data collecting apparatus to be thereby automatically processed for obtaining various information of flaw possibly present within an object to be tested.

Abstract: A method and apparatus for determining the location and size of structural defects in a body of solid material, particularly regions of thermoplastic deformation in semiconductor wafers. An acoustical focused beam generated by an ultrasonic transducer, having a pulsed frequency of at least 75 MHZ, is transmitted through the body to provide an attenuated signal pattern which manifests structural defects, such as slip planes which can result in wafer warp, as well as cracks, bubbles, foreign particles or segregation zones and internal interfaces.

Abstract: An apparatus for displaying ultrasonic images picked-up by an ultrasonic microscope including a digital scan converter having three image memories for storing successively picked-up three ultrasonic images. The digital scan converter functions to reconstruct a color image from the three ultrasonic images by simultaneously reading ultrasonic image signals out of the image memories as red, green and blue color signals.

Abstract: A compound ultrasonic scan of an object is effected with a pair of transducers mounted adjacent to the object but spaced apart from each other. Each transducer is operated as a "wobbler" transducer. That is, the transducer transmits pulses of ultrasonic energy into the object and receives echoes from acoustic discontinuities in the object while the transducer is oscillated mechanically, through a predetermined angle, about an axis which passes through the transducer.

Abstract: Apparatus for continuously orienting an ultrasonic transducer so that the emitted ultrasonic waves remain at a normal angle of incidence to the opposing surface of an object while the transducer is being moved laterally across the surface in order to inspect the subsurface composition of the object. The sensor casing which contains the ultrasonic transducer pivots about one end of a tubular support arm, while the other end of the support arm pivots about a gearbox casing. A drive shaft passes through the support arm and has a miter gear on each end. One miter gear is engaged with a miter gear attached to the gearbox casing, and the other is engaged with a miter gear attached to the sensor casing so that the rotation of the drive shaft causes the simultaneous rotation of the support arm about the gearbox casing and, in the opposite direction, the rotation of the sensor casing about the support arm. The gearbox casing is attached to a carriage and has the freedom to roll relative to it.

Abstract: The invention relates to a surface testing apparatus in which sensors are driven with a reciprocating movement above the surface being tested. To minimize the forces which are required for the driving of the sensors, a vibratory system is provided for this movement, which is driven by an exciter system at or close to its natural frequency.