Abstract: Method and apparatus for ultrasonic flaw inspection of non-rotating tubular goods. The apparatus includes a test head with circumferential arrays of transducers oriented for inspection for each of transverse, longitudinal and wall thickness defects, and the test head includes individual pulser and pre-amplifier arrays as sequentially controlled from a remotely disposed operator console. The console includes sequential signal processing circuitry for developing and displaying defect indications for the test specimen as it is moved longitudinally through the test head.

Abstract: An ultrasonic defect monitor for a moving workpiece is disclosed, including first and second test probes on opposite sides of an area of interest. The detected signals are processed for display by both a threshold monitor circuit, and an integrator-threshold-monitor circuit each connected to an output indicating unit for providing defect indications.

Abstract: A variable delay memory system (200) has an addressable memory means (66-1) having a data input port and a data output port. A counter (206) is connected to supply a write address on bus (212) for storage of data supplied to the data input port on bus (64-1). A subtracter means (214) is connected to receive the write address as one input on bus (210) and a second input proportional to a desired delay time on bus (72-1). The subtracter means (214) is connected to supply its output as a read address on bus (216) for data stored in the memory means (66-1) to be supplied at the data output port on bus (76-1).

Abstract: An ultrasonic synthetic aperture testing apparatus comprises transmitting/receiving sections having an ultrasonic wave probe for transmitting and receiving ultrasonic waves at multiple points on the surface of a steel material, an operation section for accumulating the received signals corresponding to the distance between the multiple points and a reproduction point in a desired region of the material under testing, and a display section for displaying an image formed as a result of this accumulation operation. The ultrasonic wave probe is provided with vibrators corresponding to the respective vibration modes so that two kinds of ultrasonic waves in different vibration modes may be transmitted and received. The accumulation section is provided with a mechanism which performs accumulation and arithmetic operation for the two kinds of waves in different modes.

Abstract: The device comprises n spaced transducers associated with a generator through phase-shift means. These means are formed by members (66) for supplying, on different channels and from the same pulse of the generator, pulses with different time delays. Amplifiers are each associated with a transducer and are controlled from the pulse appearing on the appropriate channel selected by storage means. A receiver (62) associated with the transducers (12) comprises a single delay line with multiple taps closed upstream across a matched impedance and forming phase-shift means at reception.

Abstract: An ultrasound diagnosis apparatus comprising, a pulser, a transducer connected to the pulser, which is driven by drive pulses from the pulser to radiate ultrasound wave toward an object and to receive echoes returned from the object to convert the echoes into electrical signals, the thickness of the transducer changing in a direction orthogonal to the ultrasound beam traveling direction, a filter connected to the transducer for filtering the electrical echo signals from the transducer with the filter characteristic which is changed according to a change of the thickness of the transducer, signal processing circuit connected to the filter for processing the electrical echo signals passed through the filter to convert it into tomogram signal, and a monitor connected to the signal processing circuit for displaying a tomogram according to a tomogram signal from the signal processing circuit.

Abstract: An ultrasonic probe (1) for use with ultrasonic imaging apparatus for investigating the internal structure of a body contains a pair of pulse echo receivers (RA1, RB1; RA2, RB2; . . . ) for each pulse transmitter in a linear array of transmitters (T1, T2, . . . ). The two receivers (A,B) in each pair lie in a plane at right-angles to the pulse propagation axis of the associated transmitter and equidistant therefrom. The outputs from the two receivers in each pair are correlated by multiplying in multipliers (11.1, 11.2, 11.3) so that in use the time coincident components of the two waveforms in each receiver pair are emphasized, thus focussing the echo information in the longitudinal plane of symmetry (4) of the probe.

Abstract: An ultrasonic flaw detecting apparatus of electronically scanning type comprises a plurality of ultrasonic vibrator elements disposed in an arcuate array, wherein groups of N vibrator elements arrayed in the circumferential direction of an object under test are sequentially changed over to one another on one-by-one base to thereby scan an object under test with ultrasonic beams. By controlling phases of pulse signals applied to the individual vibrator elements, a region of focus of the ultrasonic beams is set at a predetermined depth of the object under test. For reception, only the echoes reflected from a predetermined focal range are selectively extracted by providing corresponding window or gate means.

Abstract: In an exemplary embodiment, a transducer element row W.sub.1 through W.sub.m has a signal delay device for the delay of arriving echo signals in such a manner that phase balance of the individual signals result at the output. It is the objective of the disclosure to construct such an apparatus with which, given a specified number of transducers, the grating lobes in the directional response of the antenna are eliminated, and nevertheless the electronic outlay can be kept within boundaries. This objective is achieved in that the signals are transmitted, in groups, respectively, by the delay device to individual adders whose output signals are linked in a unit for quasi-multiplicative processing. In the case of digital technique, through binary signal processing, a considerable simplification results accompanied by the elimination of the interfering directional response of the resolution capability.

Abstract: A process and a device for the nondestructive ultrasonic testing of the material of generator rotor teeth providing with an inserted slot wedge, using a probe arrangement including transmit probes, reference probes and defect detection probes which are disposed on a support plate in such a manner as to be movably attached to the teeth, wherein ultrasonic beams are transmitted and reflected by the rotor teeth flanks and the reflected beams are received in a reference probe utilizing a two-fold deflection of the sound at the tooth flanks which are inclined with respect to the tooth back. An ultrasonic beam, reflected by any existing defects of a given type and orientation, is selectively received outside the receiving range of the normally reflected acoustic beam by means of a defect detection probe, and the damaged locations is detected by comparison of the ultrasonic signals received by the reference and defect detection probes.

Abstract: Beams of ultrasound are transmitted into a rail. The transmission alternates between vertical and oblique beams. Transmission of the beams and reception of ultrasonic echoes is accomplished by a probe which includes a two channel ultrasonic transducer. The echoes are displayed simultaneously on two linear arrays of LED's which are arranged to resemble the relationship between a vertical beam and an oblique beam.

Abstract: An ultrasonic scanning apparatus includes a transducer plate, a plurality of elongated, parallel driving line electrodes arranged on one surface of the transducer plate and a plurality of elongated, parallel grounding line electrodes arranged on the opposite surface of said transducer plate. The driving line electrodes and the grounding line electrodes intersect to effectively form a matrix of individual transducer elements capable of both emitting and receiving ultrasonic beams. The apparatus includes control means to sequentially activate selected arrays of the individual transducer elements to produce and focus the resultant ultrasonic beam and to sequentially switch selected arrays of the individual transducer elements to a reception mode to vary the effective reception area of the transducer.

Abstract: A method of and a device for ultrasonic examination of an object by means of a row of N electroacoustic transducers. Each time a group of M transducers (M.gtoreq.N) thereof is selected by means of a switching member. These M transducers are first included in transmission networks, transmission signals then being applied to the converters; subsequently, they are included in receive networks, receive signals then being applied to a display device. The transmission and/or receive signals are multiplied by weighting factors between 0 and 1. The sum of the weighting factors during transmission may deviate from that during reception. During transmission and/or reception, at least two different combinations of weighting factors are used, the sum thereof being each time the same. The scanning line density can thus be substantially increased.

Abstract: The device comprises a transducer (1) which consists of two or more transducer layers (11) and (12) and which is connected to a transmitter circuit (2) which consists of a transmission network (21) and a control network (22) which comprises a first correction circuit (223) for the correction of the transfer function of the tranmission network (21). The transducer is furthermore connected to a receiver circuit (3) which consists of a receiver network (31) and an auxiliary network (32) which comprises a second correction circuit (323) for the correction of the transfer function of the receiver network (31). The correction circuits (223) and the (323) consist of an adder circuit with a number of inputs, each of which is connected to an output of a delay line (227i, 327i) whose input is connected to the output of an attenuator (226i, 326i).

Abstract: A reliable ultrasonic method for testing inner diameter cladded pipe adjacent to welds comprising use of multiple beams, bands and pulses in addition to pulseshaping and beamforming, spectral and directional averaging, as well as spatial filtering and pattern recognition. An automated inspection mode aims short shear-wave pulses from different source locations and different beam orientations to detect signals characteristic of defects. A manual confirmation mode aims both longitudinal waves and shear waves at the suspected defect and analyzes the detected returned pulses by an associated pulse pattern recognition method.

Abstract: An ultrasonic diagnostic system for observing the state within a measured object by transmitting ultrasonic waves to the interior of a measured object such as the human body and by receiving acoustic waves reflected from the object. The system employs plural probe units which contain electric-acoustic transducers and are mutually isolated. A transmitting circuit causes the plural probe units almost simultaneously to transmit ultrasonic waves having different characteristics. A receiving circuit contains filters for isolating and extracting acoustic signals having characteristics corresponding to those particular transmitted ultrasonic waves from the other acoustic signals received. This system thereby obtains an acoustic image corresponding to each scanning line, and by means of scanning the measured object with each of the probe units, a display of the object's movement is obtained with plural scanning lines.

Abstract: An ultrasonic imaging apparatus comprises transducers for transmitting ultrasonic waves and receiving acoustic. The apparatus also transmits ultrasonic waves of different frequencies simultaneously from a plurality of transducers.The frequency characteristics of the transducers are determined in a manner so as to produce the function of frequency filters. An electric filter is additionally provided for compensation. Thus, crosstalk is eliminated even when the frequency difference between the transmitting ultrasonic waves is kept small.

Abstract: Apparatus and method for measuring the thickness of a test piece by obtaining the acoustic velocity of the test piece where an ultrasonic wave is refracted into the test piece at a first point and the wave travels substantially parallel to the surface and the transit time to a second point where the wave is refracted out of the test piece is measured. The distance between the first and second points is known and the ultrasonic wave is initially transmitted into a member of different acoustic velocity than the test piece to produce the subsurface wave in the test piece.

Abstract: Method and apparatus for ultrasonic testing of tubular goods wherein plural circumferential arrays are utilized for continuous testing for specifically oriented defects. The apparatus utilizes plural ultrasonic energy transducers disposed in circumferential array for transmitting and receiving ultrasonic energy toward a central bore area. Further support structure serves to dispose the tubular goods in the central bore area for movement relative to said plural ultrasonic energy transducers while fluid enclosure means, also including a central bore area as defined by a slidable seal, maintains a fluid environment between each of the plural ultrasonic energy transducers and the tubular goods. The plural ultrasonic transducers are then repetitively energized and received energy variations due to discontinuities in said elongate goods are then output as an indication of quality.

Abstract: An ultrasonic sector scanner using rotating transducers includes a transducer support wheel having a circumferential rim surface with a plurality of recessed seats within the circumferential surface for receiving inwardly facing transducers. The wheel and recessed seats provide accurate alignment of the transducers and acoustic mirrors direct ultrasonic energy between the transducers and ports.

Abstract: Two ultrasonic wave beams of different frequencies are emitted into a body under consideration from different locations on a surface of the body and a scattered wave beam created at a scattering point in the body by the interaction between the two ultrasonic wave beams is received. The emitting locations of the ultrasonic wave beams and the receiving location of the scattered wave beam are caused to scan. Thus, the stress distribution in the body is measured on the basis of the received outputs resulting from the scanning.

Abstract: In a method for ultrasonically measuring the thickness between opposed surfaces of a workpiece from one surface, a velocity parameter of ultrasonic longitudinal waves through the material of a workpiece is measured at a location along a first surface of the workpiece. Ultrasonic longitudinal waves are transmitted from one surface to the opposite surface, and the ultrasonic waves reflected from the opposite surface are received and a time parameter between transmission of the longitudinal waves and reception of the reflected waves is measured. The thickness between the opposed surfaces is determined from the measured velocity parameter and the measured time parameter. A device for measuring the thickness of a workpiece from one surface includes a transducer assembly with a pair of spaced apart transducer units each having a coupling member and a piezoelectric element mounted thereon.

Abstract: Apparatus and method for acoustically inspecting hot flat plates while on-line by utilizing an array or arrays of transducers continually spaced a set distance from the bottom of the plates by serrated rollers spring mounted with the array of transducers in a container with overflowing liquid wetting the passing plate to acoustically couple the transducers to the plate and a spray of sufficient force to temporarily cool the hot plate and dispel steam and vapor formed, the spray being in a direction opposite the direction of travel of the hot plate; and support of the unit on a track mounted carriage, with the liquid reused through a reservoir connected system. It is critical that the spray be at an angle of 27.degree. or less to the horizontal and that the spray have sufficient force to have an apparent liquid velocity of at least 44 feet per second, adding the speed of the water and the hot plate together.

Abstract: An ultrasound examination apparatus comprises a processing circuit for echo signals from a mosaic of ultrasonic transducers which are made of an electrostrictive material with a non-remanent polarization. These signals are applied to processing channels which comprise coupling means (10i) for coupling the electrodes of the transducers to a circuit (20) for generating a polarization voltage ramp whose waveform is the inverse of that of the attenuation curve of the ultrasonic signals in the structures examined. These coupling means, for example, an RC circuit (11i, 12i) or a transformer (13i) enable the polarization voltage to be applied to the electrodes while inhibiting the transmission to the part of the processing channels which is situated behind the coupling means.

Abstract: An ultrasonic testing method permits investigating the nodal point in the profile of a cast wheel of a motor vehicle between clinch and wheel flange. Hollow spaces occurring in this area may be tolerated when the remaining wall thicknesses between the profile legs do not drop below a certain thickness. In order to be able to check a wheel in one single measuring process and with a simple measuring geometry, two of the three intermediate leg parts are tested by direct testing by an evaluation of the echo height in consequence of lateral contraction of ultrasonic energy or in consequence of partial reflection which allows one to make conclusions with regard to the cross section and sound spots of the material through which ultrasound was sent, while the remaining part is measured by means of a simple travel time transversely to the residual wall. An apparatus for performing this method is disclosed.

Abstract: A method for ultrasonic fault localization, in which the fault is determined from the travel time of the ultrasound pulses and the echo pulses, in which an echo pulse reflected in the workpiece at a fault is received at three different points on the surface, the electronic echo pulses are electronically added in phase with a delay dependent on the different propagation times, and fed to an electronic time window such that during the open time of the time window, only echo pulses from the fault are picked up. The fault is displayed graphically as to size, position and shape.

Abstract: A parameter representative of a physical property of a continuously moving metal strip is determined by repetitively generating acoustical shock waves, containing ultrasonic frequencies, and adjacent the strip and measuring the speed of transmission of the shock wave in the strip. An electric spark generator with a collimator feeds the acoustic energy to the strip 10 and four microphones arranged as a first pair on opposite sides of the strip spaced a known distance from a second pair also on opposite sides of the strip pick up the signal transmitted through the strip. The difference between the mean time of arrival at the first pair and the mean time of arrival at the second pair enables the velocity of propagation in the strip to be determined despite movements of the strip transverse to its plane. The velocity of propagation in particular may be used as a measure of Young's modulus and hence, in the case of a material such as aluminium, as a measure of the temperature of heat treatment.

Abstract: In an ultrasonic scanner, a plurality of sound transducers are operable to project sound beams defining spaced sound paths into a sectional plane of an object and to receive echoes therefrom. The sound paths may be oscillatingly swept in the sectional plane during operating cycles so that the sound path of each sound transducer coincides at least once during each oscillating cycle with a predetermined line of reflection in the sectional plane. A fluorescent screen receives some of the echo signals to display them in a section scan mode while a sound transducer control operates each sound transducer when none of the sound paths coincides with the predetermined line in each given cycle. A scan mode control operates when the sound path coincides with the predetermined line for displaying the section scan mode in response to the echo signals in a different scan mode several times per cycle.

Abstract: A method, a device and a transducer for dimensional measurement of objects by means of ultrasonics, where the objects are carried past at least an ultrasonic measuring device consisting of a combined transmitter/receiver or separate transmitter/receiver. The reflected ultrasonic signals are used to determine characteristic three-dimensional dimensions of the objects. Said device or devices are arranged either such that the ultrasonic beam or beams therefrom are provided with a reciprocating movement which substantially crosses the direction of movement of the objects or by letting the ultrasonic beam or beams therefrom be stationary. The delay of the reflected signals is used to form a three dimensional image of the object by means of a computer, said image being compared with known images for identification. The ultra sonic measuring device has a narrow, substantially rotation-symmetric radiation diagram.

Abstract: An ultrasonic scanner for use in medical diagnosis which produces two different types of scans. The scanner includes a housing carrying one or more ultrasonic transducers which traverse an arcuate path. A first reflector is positioned within the arcuate path to intercept ultrasonic waves and converge them at a point beneath the scanner in order to produce a skin centered sector scan, which is useful for viewing through small acoustic windows such as intercostal regions. A pair of reflectors, one of which is positioned horizontally with respect to the first reflector and the transducers, are utilized to form a wide aperture sector scan which diverges upon exiting the scanner housing. The wide aperture scan is useful for scanning spaces such as the abdomen which include relatively few obstructions.

Abstract: A method and apparatus for investigating a rod-like body which is anchored in a surrounding material and which has an accessible end, for determining the state of the anchorage of the body and its length. Transient elastic oscillations are excitated in the accessible end of the body. The oscillations comprise a flexural wave causing a deformation of the body varying with respect to amplitude and phase over the cross-section of the body. The flexural wave propagates in the longitudinal direction of the body and is partially reflected at discontinuities of the body and/or the anchorage. Transient elastic ocillations comprising flexural waves reflected at such discontinuities and returning to the accessible end of the body are received and detected. The position and magnitude and/or type of at least some of the discontinuities are estimated with the aid of time-position and amplitude of the reflected flexural waves.

Abstract: Ultrasonic test equipment for testing the welding seam a thick wall includes transducers arranged in tandem and along the welding seam, whereby a tandem pair inspects in any instance two surface-near zones (inner and outer surface) as well as an interior zone. One of the transducers of the pair participates in a function test. Two pairs cover the same zones, but from opposite sides.

Abstract: A defect such as a crack in a steam pipe is monitored by employing ultrasonic techniques to generate defect dependent signals and employing an Adaptive Learning Network (ALN) model to analyze the signals, whereby changes in the defect can be detected.

Abstract: A way of automatically inspecting a machined part, for example, to a tolerance of 0.001 inches. A minicomputer monitors a change in phase of acoustic wave energy impinging upon a sample part and compares it with a change in phase of such energy for a standard or master part, any difference between the monitored changes being interpreted to determine if the sample is within acceptable tolerance limits. The inspection approach described uses no moving parts and can be used to inspect many dimensions of a part simultaneously in less than a second. Acoustic wave energy can be used to inspect parts of any shape. The inspection system disclosed can be used, as well, to monitor the geometry of an object over time to note any changes in said geometry. And the concepts of the inspection system can be employed in conjunction with robot-controlled devices to provide close-positioning data for such devices.

Abstract: A scanning unit comprises two sound transducer heads for projecting sound beams, which are caused to scan a common section plane. Echo signals are derived from the echoes generated in response to said sound beams and are displayed on a fluorescent screen at locations which are geometrically coordinated with the locations at which the corresponding echoes have originated. The sound beam from one sound transducer head scans the section surface in an area which is generally rectangular or has only slightly divergent side edges. The sound beam from the other sound transducer head scans the section surface in an area which has greatly divergent side edges. These areas of the section surface are displayed on different areas of the fluorescent screen. Such scanning unit can be adapted to object of various shapes.

Abstract: An exemplary embodiment comprises an ultrasonic applicator for line-by-line ultrasonic scanning and a picture tube, for example, a television monitor for the visible echo image. The echo lines developing from the ultrasonic applicator are alternately stored in alternating memories and read out to the picture tube. The reading-out ensues singly or multiply in such reading-out times as correspond to the line sweep time of the picture tube. An imaging apparatus is desired which, in addition to direct reproduction, also renders possible the reproduction of stored ultrasonic images given the smallest technical outlay while doing without extravagant image memories.

Abstract: Methods (and apparatus) for nondestructively testing a body of material having a surface in contact with a gaseous environment (e.g. air, nitrogen, or inert gas), that comprise (A) the step of (and means for) directing to a region at the surface of the body a pulse of laser radiation having sufficient energy density and sufficiently long wavelength to initiate in the adjacent gas a blast wave that impinges on the surface and provides an ultrasonic wave in the body, and (B) the further step of (and means for) detecting a portion of the ultrasonic wave that has been affected by the body. The radiation directing means typically comprises a laser that provides a pulse having a duration of about 0.01 to 10 microseconds, and means for focusing the pulse to provide an energy density of at least about 5 Joules per square centimeter. The detecting means typically comprises an electromagnetic or capacitive transducer.

Abstract: In an ultrasonic transducer probe having multiple rotating transducer elements the transducer outputs are switched in response to sine and cosine signals from a resolver. The same signals are used to switch and time the display scan. If the transducers are misaligned a multiple blurred image may result. It is proposed to modify the resolver signals changing the phase of the signals for at least one transducer to bring the display signals into registration. In one example it is achieved by, for at least one transducer element output, mixing a proportion of at least one of the sine and cosine signals with the other.

Abstract: In a rotating probe ultrasonic system the effective PRF may not be sufficiently high for certain purposes, such as examination of the foetal heart. The invention combines fixed transducers looking at a limited region with a rotating probe scanning over a larger region to give a higher effective PRF in the limited region. The two displays are preferably separate although the display of the larger region may conveniently indicate the location of the limited region.

Abstract: An electronically scanned phased array diagnostic system for describing internal structure of a subject by the use of ultrasonic energy. The system includes a transducer unit with an array of ultrasonic energy conversion segments and control circuitry for actuating the segments to direct ultrasonic energy into the subject. Imaging circuitry is included for interpreting electrical return signals produced by the segments in response to ultrasonic echoes. The imaging circuitry includes transmission delay circuits for imposing time delays on the return signals for steering and focusing system echo reception. Each transmission delay circuit includes first and second delay elements for impressing first and second delay time components on the return signals. Each pair of the first delay elements are coupled in parallel with separate transducer elements, and serially combined with a downstream second delay element.The first delay elements provide a portion of the reception steering capability.

Abstract: Apparatus is provided for measuring the roll gap in roll stands with automatic gap control. The apparatus comprises two relatively movable components which may interfit telescopically. The two components have respective measuring surfaces at one of which is located a pulsed ultrasonic signal transmitter. A sound receiver is located either on the same measuring surface or on the other measuring surface. Measuring means are provided for measuring the time taken for the sound pulses to travel between the measuring surfaces.

Abstract: An acoustic imaging system for displaying an object viewed by a moving array of transducers as the array is pivoted about a fixed point within a given plane. A plurality of transducers are fixedly positioned and equally spaced within a laterally extending array and operatively directed to transmit and receive acoustic signals along substantially parallel transmission paths. The transducers are sequentially activated along the array to transmit and receive acoustic signals according to a preestablished sequence. Means are provided for generating output voltages for each reception of an acoustic signal, corresponding to the coordinate position of the object viewed as the array is pivoted. Receptions from each of the transducers are presented on the same display at coordinates corresponding to the actual position of the object viewed to form a plane view of the object scanned.

Abstract: A method of determining depth propagation of a defect in a body by ultrasonic materials testing wherein a first angle probe having an ultrasonic wave transmitting oscillator produces a scatter signal at structural inhomogeneities of a body formed with a defect and the scatter signal is received by an ultrasonic wave receiving oscillator of a second angle probe, which includes: transmitting an ultrasonic wave at a first angle along a first line in direction towards the defect so that the scatter signal thereat is shadowed by the defect and diminished in intensity; receiving the diminished signal from the defect at a second angle in a direction along a second line intersecting with the first line at a defect, transmitting additional ultrasonic waves and receiving diminished scatter signals along respective lines intersecting at the defect at varying depths of the body and ascertaining the depth propagation of the defect by a marked increase in intensity of the received signal when the intersection of the respec

Abstract: In the illustrated embodiment the ultrasonic applicator is activated to emit ultrasonic pulses along a plurality of scan lines simultaneously, the echo signals of all simultaneously scanned lines being stored and then rapidly read out during ultrasonic scanning along a further set of lines, the individual lines of each set being displayed in sequence and the successive sets being correspondingly displaced on the image screen so as to reproduce the ultrasonic image.

Abstract: N elementary transducers are distributed regularly along a line of scanni An ultrasonic frequency receiver is associated with phase lag means. The distribution over n successive elementary transducers of the phases corresponding to focusing at a predetermined distance or several successive distances from the line is stored. That distribution corresponds to several Fresnel zones. Switches first connect a generator to a group of n' transducers corresponding to the central Fresnel zone of said stored distribution and later connect a group of n transducers to the receiver direct and via the phase lag means according to the stored distribution(s). The groups of n' and n elementary transducers are shifted along the line at intervals of time. The phase lag means may consist of inverter means causing a phase angle of .pi..

Abstract: Combination Doppler and B-scan ultrasonic imaging apparatus is disclosed which includes visual display means for the simultaneous visual display of received ultrasonic Doppler and B-scan information. The apparatus includes first and second focused transducers associated with the Doppler and B-scan systems, which transducers are individually mounted for movement along parallel linear paths. The transducers each comprise a generally semi-cylindrical shaped body of piezoelectric material having opposite end faces upon which electrodes are disposed for connection to Doppler and B-scan transmitter and/or receiver units. The flat side walls of the piezoelectric bodies are positioned closely adjacent a mid-plane extending between the transducers, and means are provided for focusing the transducers at substantially the same depth for operation along a common focal region at, or adjacent, the mid-plane. One such focusing means includes acoustic lenses carried by the piezoelectric bodies.

Abstract: A way of automatically inspecting a machined part, for example, to a tolerance of 0.001 inches. A minicomputer monitors a change in phase, for example, of wave energy impinging upon a sample part and compares it with a change in phase of such energy for a standard or master part, any difference between the monitored changes being interpreted to determine if the sample is within acceptable tolerance limits. The inspection approach described uses no moving parts and can be used to inspect many dimensions of a part simultaneously in less than a second. Acoustic waves or microwave electromagnetic wave energy can be used to inspect parts of any shape. The inspection system disclosed can be used, as well, to monitor the geometry of an object over time to note any changes in said geometry. And the concepts of the inspection system can be employed in conjunction with robot-controlled devices to provide close-positioning data for such devices.

Abstract: A fast ultrasonic scanner for soft tissue imaging and/or characterization has a transmitter with a divergent beam pattern and an arcuate array of receivers. The propagation delay time of a short acoustic pulse traversing a water bath and immersed specimen depends on the velocity distribution and is detected at each receiver. Digital data is derived from the receiver signals at many angular positions of the scan apparatus and is used to compute a reconstruction of the velocity distribution in the specimen. The instrument provides quantitative measurements of bulk tissue and has application in breast examination and mass screening for breast cancer.

Abstract: An arrangement for the non-destructive testing of articles in which a head, carrying at least one ultrasonic testing transducer, is caused to reciprocate so as to impact upon the article to be tested with an impulsive blow of short dwell time once during each reciprocation, the transducer element carrying out a testing operation during the dwell time of each impact.