Abstract: The invention relates to a device for detecting faults in and/or measuring the wall thickness of continuously moving strips, sections or tubes of plastics, using ultrasonic signals. To this end a number of ultrasonic heads (A, B, C, D) with transmitters and receivers are disposed distributed over the width of the strip or section or the periphery of the tube. The signal, emitted by a transmitter of an ultrasonic measuring head (3) and reflected without scatter, is received by the receiver of said ultrasonic measuring head (3), while the scattered signals reflected on the tube, section or the like are received by the receivers of its adjacent ultrasonic measuring heads (A, B). The inclusion of the scattered and reflected signals in the measurement appreciably increases the measured area per measurement in comparison with using exclusively the signal directly reflected without scatter.

Abstract: The geometry of a cavity in a cast, molded or machined part is compared to that of a reference part. Measuring the amplitude or phase shift of an acoustic wave traveling through the sealed cavity, at a multiplicity of predetermined frequencies, forms an acoustic spectrum, unique to the geometry of the cavity. The acoustic spectrum of the part under test is compared to the acoustic spectrum obtained from the corresponding cavity in a reference part.

Abstract: Methods and apparatus for ultrasonically scanning cylinders are provided. The methods and apparatus employ as few as one ultrasonic sensor for full immersion scanning and defect detection. Self-centering fixturing spins the cylinder, reducing vibration, allowing for fast ultrasonic scans. To create the 45 degree angle beam shear waves for the circumferential scans, the ultrasonic sensor is offset from the centerline of the cylinder, creating the correct angle for excitation of the shear wave.

Abstract: A method for inspecting a titanium-based alloy that comprises alpha phase grains to detect flaws in the titanium-based alloy, the titanium-based alloy comprises an alpha phase that is provided by thermomechanically processing the alloy to provide a microstructure which comprises the alpha phase that defines an average grain size and a crystallographic orientation of the grains of the alpha phase that is highly randomized. The method comprises ultrasonically inspecting the titanium-based alloy using an ultrasonic beam, the ultrasonic beam comprising a cross-sectional area that is less than the average grain size of the alpha phase in the titanium-based alloy; and determining flaws based on the step of ultrasonic inspecting.

Abstract: A method and system are provided for detecting a void in backfill material such as soil surrounding a buried conduit such as a pipeline. The void is detected by monitoring an acoustic response from the conduit in response to acoustic excitation of the interior of the conduit. An analysis of changes in the acoustic response is then related to the presence or absence of a void in the backfill material.

Abstract: An ultrasonic ice detector that can be mounted directly to the skin of an aircraft includes a transducer that is coupled to the interior surface of the skin, and transmits acoustic vibrational energy through the skin. A reflector bar having a reflector surface is mounted on the interior surface of the skin at a location spaced from the transducer and is effective to reflect acoustic energy back to the transducer. The reflector bar is raised from the interior surface and preferably has a width equal to the width of the acoustic wave that is generated by the transducer at the reflector location. The transducer and reflector are non-intrusive and do not alter the aircraft skin structural integrity. The arrangement provides an accurate, responsive sensor for determining presence of ice or other contaminants on the exterior surface of the skin.

Abstract: This invention intends to provide a method for inspecting an inner state of an object by determining whether or not any foreign matter is generated inside the object material without being affected by any outside state of the object. This method comprises irradiating waveform of ultrasonic wave to an object whose inner state is desired to be inspected from outside, extracting waveform of a reflected wave traveling inside the object, detecting a difference of acoustic impedance of the foreign matter from the waveform of the reflected wave by extracting a deflection of the waveform and detecting for presence/absence of the foreign matter inside the object or presence/absence of the foreign matter and a quantity of the foreign matter.

Abstract: A novel method of non-destructive die crack inspection of a plastic encapsulated integrated circuit (PEIC) uses a scanning acoustic microscope, such as a C-mode scanning acoustic microscope. To generate scan of a die surface of the PEIC, the width of a data gate of the microscope is set to scan only the die surface. Then, the data gate is moved to cover only die subsurface reflection area on a screen of the microscope, and scan of the die subsurface is generated.

Abstract: A titanium article for an ultrasonic inspection is provided in which the titanium article can be ultrasonic inspected for determining its acceptability in for microstructurally sensitive applications. The ultrasonic inspection method comprises providing a titanium article, directing ultrasonic energy of ultrasonic inspection to the titanium article; scattering reflected energy in the titanium article; determining an amount of noise generated by the ultrasonic inspection of the titanium article; and characterizing the titanium article as acceptable if the amount of noise as a function of ultrasonic frequency or wavelength is characteristic of predominantly Rayleigh scattering and the magnitude of the noise is less than a pre-determined noise level. The titanium article comprises an uniform-fine grain microstructure. The uniform-fine grain microstructure generates predominantly Rayleigh scattering when undergoing ultrasonic inspection. The invention also sets forth a method of forming a titanium article.

Abstract: A method is provided for obtaining dimensional accuracy in a seal assembly. The seal assembly includes a substrate comprised of a material that reflects ultrasonic waves. The seal assembly also includes a deformable sealant material that may, for example, surround the substrate. The method can include ultrasonically measuring a thickness of the sealant between a face of the sealant and a surface of the substrate. The thickness of the sealant is reduced if it exceeds a predetermined value.

Abstract: The invention describes a method and system for detecting anomalies in a material. The method comprises the steps of transmitting waves through the object, receiving the waves after passage through the object, determining more than one reference characteristic, measuring more than one characteristic of the received wave, comparing a first reference characteristic with a first characteristic of the received wave to create a first factor, comparing a second reference characteristic with a second characteristic of the received wave to create a second factor, combining the first factor with the second factor to create a defect index, and identifying a location of one or more anomalies in the object using the defect index. The step of determining the reference characteristics may comprise transmitting another wave of known characteristics through a material free of anomalies to produce a standard wave, and measuring one or more characteristics of the standard wave.

Abstract: An ultrasonic computed tomography tree or log scanner has a plurality of ultrasonic transceivers carried on a belt (102) sized to encircle a tree (100). The belt includes an apparatus for engaging is tightly around the tree (104). The transceivers are strapped around the tree, and their mutual relative distances are known. Electronic circuitry energizes the transmitters in a known sequence. The signals received at each of the receivers are also collected and analyzed. Computed tomographic techniques analyze the time of arrival of the acoustic pulse that is first to arrive at each receiver. A signal processor generates a two-dimensional image of a slice of the tree (110) at the locus of the belt.

Abstract: An ultrasonic testing method uses surface waves to prevent false detection of primary cracks, to lower the level of structural noises from grain boundaries, and to improve the detectability in the ultrasonic testing by surface wave testing of hot rolling rolls. A surface wave probe 10 capable of transmitting and receiving a surface wave is provided with a piezoelectric element 10A, a resin wedge 10C disposed on the front surface of the piezoelectric element 10A and a damping block 10B disposed on the back surface. The surface wave probe 10 is driven to produce a short pulse having a pulse length being at most 2.5 times the wavelength of the surface wave to be produced. A coupling liquid medium is supplied to the probe 10 in accordance with the peripheral speed of the roll to be tested. Depending on the height of the reflected waves measured, the grinding allowance of the roll is determined, and the roll is ground according to the thus-determined grinding allowance.

Abstract: An aircraft has several ultrasonic phased arrays acoustically bonded to parts of its structure to be monitored. The arrays are energized to produce an ultrasonic beam that scans the structure in two planes. A monitor receives the output from the arrays produced by reflection of energy from discontinuities within the structure. When there is a change in these outputs, the monitor signals a pilot display unit and a flight control system such that the aircraft flight envelope can be restricted to minimize damage.

Abstract: A method for evaluating bonding properties of a metallic pipe, the method comprises steps of measuring, in advance of a pipe expansion operation, at least one selected from a degree of shape discontinuity, a degree of defect at a bonding portion, and a degree of change in crystal structure, and comparing a measurement value with a predetermined threshold value to evaluate suitability of the bonding properties for applying pipe expansion.

Abstract: A process and device are disclosed for recognizing foreign bodies in viscous or fluid masses with lumpy foodstuffs. The mass to be checked runs through a measurement section, in which, pulsed ultrasonic signals are emitted through the mass, are reflected after passing through the mass, and after passing again through the mass they are received and compared with the ultrasonic echo of the reflection surface. When the changes of the received signals exceed a predetermined threshold value, a warning or actuating signal is generated to interrupt mass advance. The parameters to be evaluated for the signal may be their amplitudes, as well as the speed of change of their amplitudes or the propagation times.

Abstract: A flaw detection system using acoustic Doppler effect for detecting flaws in a medium wherein there is relative motion between the medium and system includes a transducer, spaced from the medium to be inspected, for introducing to and sensing from the medium an acoustic signal that propagates in the medium at a predetermined frequency; and a detector, responsive to the sensed propagating acoustic signal, for detecting in the sensed acoustic signal the Doppler shifted frequency representative of a flaw in the medium.

Abstract: A method of detecting corrosion on an elongate member, such as a pipe. Far side and near side electric pulses (waves) are transmitted into a magnetically permeable pipe at spaced locations to travel toward one another. These are synchronized to intersect at various locations on the pipe. The resulting wave forms are analyzed by combining adjacent wave forms resulting from pulses intersection at spaced locations. Two combined wave forms are analyzed by subtracting one from the other to produce a difference wave form and the difference wave forms are compared to detect corrosion.

Abstract: A flaw detection system using acoustic Doppler effect for detecting flaws in a medium wherein there is relative motion between the medium and system includes a transducer, spaced from the medium to be inspected, for introducing to and sensing from the medium an acoustic signal that propagates in the medium at a predetermined frequency; and a detector, responsive to the sensed propagating acoustic signal, for detecting in the sensed acoustic signal the Doppler shifted frequency representative of a flaw in the medium.

Abstract: A system and method of detecting anomalies and/or grain variations in a wooden member. At least one ultrasonic transmitter applies an ultrasound waveform into a surface of a wooden member so as to generate a multiplicity of ultrasonic waves including, e.g., longitudinal and shear ultrasonic waves. These ultrasonic waves are measured after propagation through the wooden member by at least one ultrasonic receiver disposed on the same surface of the wooden member. At least one ultrasonic receiver may also be placed opposite the ultrasonic transmitter so as to detect radial transmission of the longitudinal ultrasonic wave at a point across from the wooden member. The received ultrasonic waves are processed to determine anomalies and/or grain variations in the wooden member at positions of the wooden member between the ultrasonic transmitter and the ultrasonic receiver(s). The ultrasonic transmitters and receivers may be placed in rollers to facilitate high-speed, in-line processing of wooden members.

Abstract: A flaw detecting method and apparatus for continuously testing a strip that is continuously carried through a liquid includes features for reducing air bubble generation in a liquid. The apparatus includes a liquid, carrying rolls for passage of the strip through the liquid, and ultrasonic testing probes arranged in the liquid for testing the strip. A carrying roll in contact with the liquid is fully immersed. Air bubble generation is inhibited to improve the testing reliability by at least one of (a) shielding the liquid dropping from the portion of the strip leaving the liquid, (b) reducing the dropping force of the liquid onto the liquid surface by inclining the strip, (c) installing the fully immersed carrying roll at a depth of at least 5 mm in the liquid, and (d) using a carrying speed of less than about 200 m/min. Upon manufacturing steel strips, testing is carried out in the stage of hot-rolled steel sheet, or, preferably, in pickling equipment.

Abstract: A cleaving tool provides pressurized gas to the edge of a substrate in combination with a sharpened edge to cleave the substrate at a selected interface. The edge of the tool is tapped against the perimeter of a substrate, such as a bonded substrate, and a burst of gas pressure is then applied at approximately the point of contact with the edge of the tool. The combination of mechanical force and gas pressure separates the substrate into two halves at a selected interface, such as a weakened layer in a donor wafer.

Abstract: An aspect of the present invention is an apparatus for inspecting a base of a liquid filled tank for corrosion, having (a) a housing for use in the liquid filled tank; (b) a set of one or more ultrasonic transducers mounted to the housing, for directing one or more ultrasonic pulses at the base, where the ultrasonic pulses each have a frequency selected to produce a return signal from the base, and for receiving this return signal; and (c) a data capturing system for storing information from these return signals. Optional features include a second set of one or more ultrasonic transducers for directing one or more ultrasonic pulses at the liquid/gas interface at a frequency selected to produce a return signal from the liquid/gas interface, a data analysis system, a locomotive system, and a spatial location system.

Abstract: Method for measuring residual stress in a metallic specimen wherein, by means of an ultrasound transducer an ultrasound entry wave having a ground frequency is introduced into a surface of the metallic specimen, the ultrasound entry wave is measured by means of an entry wave detector and the succeeding ultrasound exit wave is measured by means of a exit wave detector and the measured values of the ultrasound entry and exit wave are used to determine residual stress, characterized in that, for a selected entry gate time the value of the entry convolution integral of the measured ultrasound entry wave and a periodic wave of the ground frequency is calculated and during a selected exit gate time the value of the exit convolution integral of the measured ultrasound exit wave and a periodic wave of the ground frequency is calculated and the residual stress is determined using the calculated values of the entry convolution integral and the exit convolution integral.

Abstract: A &ggr;-ray tool and acoustic logging instrument combination includes in an elongated housing a transmitter for sound and at least one and preferably two, sound sensors located at predetermined distances above the transmitter. The sound sensors are separated from the sound transmitter by a steel tube that has a layer of lead bonded onto its exterior surface and has electronic components of the instrument placed into its interior. The portion of the housing that surrounds the lead bonded steel tube consists of fiberglass, polytetrafluoroethylene (TEFLON®) or other material which does not conduct sound whereby the lead-bonded tube and the immediate housing around it act as a sound isolator bar. The transmitter and the sound sensors are surrounded by portions of the housing that comprises slotted steel to allow free flow of acoustic energy through these portions of the housing.

Abstract: A method for inspecting welds uses a single EMAT tranducer operated in pulse-echo mode that sends and receives Rayleigh waves to detect defects in a weld between sheet plates of dissimilar thicknesses.

Abstract: A tube flaw detecting method detects a flaw portion in a heat exchanger tube constituting a boiler furnace wall using two probes, enabling one to carry out appropriate inspection work with a high efficiency. A transmitter probe and a receiver probe are juxtaposed in a circumferential direction, and an ultrasonic wave is transmitted from the transmitter probe to propagate. Repeated reflections occur at a tube inner surface and tube outer surface, and the wave is reflected at a crack extending in the circumferential direction to return, propagating likewise to be received by the receiver probe so that existence of the crack is confirmed. Thus, inspection work for a crack can be done with certainty with a simple arrangement.

Abstract: The technique is based on comparing the spectral response of the "suspect" signal with that of a reference signal. The "suspect" signal is a signal detected in the weld heat-affected zone by a high-frequency (10 MHz), angle-beam (typically 45 degree) shear wave transducer operated in the pulse-echo mode. The reference signal is taken from the base metal next to the weld or heat-affected zone with two matched transducers of the same kind as the pulse-echo transducer but operated in the pitch-catch mode. The two signals are gated and Fast Fourier Transformed to the frequency domain for comparison. Relative to the reference spectrum, the high temperature hydrogen attack spectrum has an amplitude which increases with an increase of frequency, while welding defects and inclusions have the same frequency dependence as the reference spectrum. Therefore, localized high temperature hydrogen attack can be easily differentiated from other defects due to its unique spectral response.

Abstract: An electromagnetic acoustic transducer is provided which includes magnets and a sheet type coil unit. The magnets are permanent magnets or electromagnets to provide a static magnetic field to an object to be inspected. The coil unit includes a pair of spiral or meander coils of an electrically conductive material, sandwiched between upper and middle insulation sheet and middle and lower insulation sheet. The coils are used for transmission and reception, respectively. All the ends of the respective coils extend through throughholes formed through the upper and middle insulation sheets to the surface of the ultrasonic transducer, and are connected to external leads. The ends for earth are commonly connected to form a common ground terminal. The inspection system with the electromagnetic acoustic resonance which is a combination of resonant technique and a non-contact electromagnetic acoustic transducer can accomplish evaluating the absolute value of ultrasonic attenuation.

Abstract: A method and apparatus for nondestructive inspection of packaged integrated circuits and defect detection in the integrated circuits. In a scanning acoustic microscopy system, a packaged integrated circuit under test 31 is placed in a tank containing an acoustic transmission medium such as de-ionized water. An acoustic reflector 29 is placed beneath the integrated circuit 31. A pulse-echo mode transducer 17 is used to scan the area containing the integrated circuit 31 with ultrasonic energy. The reflective signal energy is captured by the transducer 17 and the signals are digitized and stored. A computer system analyzes the reflective signal amplitude, and presents a visual image based on where the reflective signal was strong and where it was weak. In a preferred embodiment the image is presented so that the signal from the reflective plate is shown as a dark region where the reflection was weak or zero.

Abstract: A method of detecting corrosion on an elongate member, such as a pipe. Far side and near side electric pulses (waves) are transmitted into a magnetically permeable pipe at spaced locations to travel toward one another. These are synchronized to intersect at various locations on the pipe. The resulting wave forms are analyzed by combining adjacent wave forms resulting from pulses intersection at spaced locations. Two combined wave forms are analyzed by subtracting one from the other to produce a difference wave form and the difference wave forms are compared to detect corrosion.

Abstract: A method for producing objective, verifiable data which discovers and documents hidden prior vehicle paint and body damage by measuring paint with non-destructive instrumentation at several locations on the exterior surface of an automotive vehicle's body panels, comparing the highest and lowest of these measurements with the standard maximum and minimum measurements, and evaluating the vehicles as to the extent and location of repainting or body damage. Another step of calculating the range of the vehicle's measurements, and comparing these measurements and their range to the normal measurement variations found on new or unrepaired vehicles provides more conclusive evidence of repainting. A vehicle is then evaluated as having one or more body panels refinished if the range of measurements is greater than normal acceptable factory variation.

Abstract: A focusing electromagnetic acoustic transducer is provided which comprises a pair of meander coils, three insulation sheets and a magnet. The meander coils are formed on both surfaces of one of the insulation sheets to be positioned such that the meander coils are coincident with each other, and they are covered with the other insulation sheets. Each of the meander coils comprises a plurality of coil segments wherein intervals between adjacent coil segments sequentially are varied from one end to the other end. The magnet is positioned above the layers consisting the meander coils and insulation sheets. The coil segments of each meander coil are straight lines in parallel with each others, sector shapes on respective circulars having the same center point, or generally circular shapes having the same center point.

Abstract: A bottle testing apparatus for testing bottles for flaws of a predetermined magnitude, the bottles having a predetermined bottle configuration and having at least one natural frequency comprising a sound system which produces sound of a character sufficient to rupture one of the bottles having a flaw of at least a predetermined magnitude but insufficient to rupture one of said bottles not having a flaw of at least said predetermined magnitude.

Abstract: A pipe (P) carries corrosive fluids (F). Ultrasonic measurements of the pipe's thickness are made with an instrument (10) to determine if it needs to be replaced. If the pipe is coated with a layer (L) of protective material (C), a time of flight (TOF) measurement is made to determine the velocity of ultrasonic pulses transmitted through the material from which the pipe is manufactured. A second measurement is made to determine the velocity of pulses through the coated pipe material. The pulse velocity is now a function of the coating thickness by knowing the two velocity values, the coating thickness is determined. An ultrasonic pulse measurement of the thickness of the coated pipe is then made. The coating thickness is then calculated by a processor (12) of the instrument. If the thickness value is less than a minimum thickness value (M), an indication is given that the pipe needs to be replaced.

Abstract: Method and equipment for the detection and identification of particles in a suspension with the aid of acoustic signals, directed at at least one measurement volume within the suspension, via reception of acoustic reflection signals, conversion of the acoustic reflection signals into electrical reflection signals, counting the number of electrical reflection signals which have an amplitude in excess of a predetermined value and converting the count into numbers of particles which are larger than a certain size, at least one curve being composed on the basis of a cumulative count of the number of reflection signals which have an amplitude in excess of a specific value as a function of the amplitude and the at least one curve being compared with predetermined standard cumulative count curves and material properties, particle concentration, particle size distribution and/or particle characteristics, such as particle shape, particle size and standard deviation thereof, are deduced from the comparison.

Abstract: A method is provided for testing prestressed concrete pipe. In the method, elastic waves are serially induced at at least three different inducing locations along the surface of the conduit. The shear wave component of each induced elastic wave is detected by at least one, and preferably two, acoustic sensors disposed at fixed sensing sites along the conduit. The relationship between at least one parameter of each induced shear wave and the distance between each inducing location and the acoustic sensor(s), are correlated and compared with standard correlations to identify structural discontinuities in the conduit. In a typical example of the method, elastic waves are induced using a mechanical hammer at multiple inducing sites around a multiplicity of annuli along the length of the conduit. Each annulus is separated from adjoining annuli by 2-4 feet.

Abstract: A method and apparatus for the measurement of a property of particles suspended in a medium are described. In one embodiment, the deformability of sampled red blood cells is measured. A pulse generator (40) provides a narrow square pulse to a transmitting transducer (35), which passes an ultrasonic wave through the sample medium (15) to be received by a receiving transducer (36). The output signal from the transducer (36) is amplified by an amplifier (41) then subjected to signal processing. The acoustic absorption of the sample is calculated and scaled with frequency. The slope of a plot of scaled absorption with frequency gives a measure of the red blood cells' deformability.

Abstract: A detecting device for detecting a physical quantity of an object, which includes a transmission signals generating device for generating first and second transmission signals of different frequencies, an ultrasonic wave transmission device that is excited by the first and the second transmission signal, for transmitting ultrasonic pulses corresponding to the first and the second transmission signal to an object, and a signal processing device for carrying out a signal processing process on the first and the second echo. The signal processing process is such that it detects phases of the first and second echo corresponding to the first and second transmission signal, which are received by the ultrasonic wave receiving device. An indeterminacy integer times as large as 2.pi.

Abstract: An apparatus for analyzing a liquid product. The apparatus includes a conveyor assembly having a conveyor belt and an agitator. The conveyor belt is constructed to deliver a unit of liquid product from the agitator to an analysis position. The agitator is constructed to impart motion to a unit of liquid product. The apparatus further includes an ultrasound transmissive pad assembly having a pad defining a chamber therein. A liquid acoustical couplant is contained in the chamber. The ultrasound transmissive pad assembly further includes an ultrasonic transducer in ultrasonic contact with the liquid acoustical couplant. The pad is positioned to contact a unit of liquid product at the analysis position. The pad has an upper portion and a lower portion and is orientated such that the upper portion contacts a unit of liquid product delivered to the analysis position before the lower portion contacts the unit of liquid product delivered to the analysis position.

Abstract: A method and apparatus for evaluation and inspection of a composite-repaired structure generates a frequency-varying electrical signal to test and evaluate the composite-repaired area. The electrical signal is converted into a mechanical signal and transmitted through the composite-repaired area of the structure. The transmitted mechanical signal is received and converted into an electrical signal for processing. The processed signal is compared with a baseline reference signal to determine whether the composite-repaired area is damaged or undamaged. The baseline reference signal is obtained at the time of the composite repair of the structure.

Abstract: There is disclosed a method and apparatus for testing inflated vehicle tires to determine internal physical characteristics such as tire pressure. The apparatus includes a waveform transceiver for subjecting a tire to be tested to a transmitted waveform and for transmitting an ultrasonic waveform from a location external to the tire under test and for receiving the ultrasonic waveform from a tire under test at a location external thereto; and a processor for interpreting the received waveform with reference to the decay or attenuation of the amplitude of the waveform with time to provide a measure of the internal physical characteristic.

Abstract: A system for the non-contact inspection and characterization of an object in which wideband (40 kHz to approximately 2 MHz) air/gas coupled ultrasonic transducers are used. The system of the present invention enables a single set of transducers to be used in an inspection/defect detection arrangement to characterize materials having a wide range of through-thickness, and other resonances. For example, the through-thickness fundamental resonance of 11 mm thick plywood is 44 kHz, 723 kHz for 2 mm thick carbon fiber, and 1.47 kHz for 0.75 mm thick polystyrene, all of which are measurable in the same system. The system is used in a method to characterize a defect by being able to operate at or near the resonant frequency of the normal material and at or near the resonant frequency of the material in a defect region to improve the accuracy of detecting specific types of defects including inclusions, material thinning, delamination and pitting by monitoring changes of various attributes (e.g.

Abstract: A method and apparatus of inspecting for flaws in a specular reflector, where the flaws having an expected length and the reflector is electrically conductive. The method includes directing a beam of an electromagnetic acoustic transmitting transducer along a beam axis toward the specular reflector for producing a reflected electromagnetic acoustic beam. The transmitted beam has side lobes with zero points therebetween, at least some of the side lobes being major side lobes. The reflected beam is received using an electromagnetic acoustic receiving transmitter set at an angle to the beam axis, the angle being selected to be at one of the zero points and past all of the major lobes of the transmitted beam to eliminate root and crown signals of the weld, in the reflected signal.

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: An objective and non-destructive test of the fused joints in an armature, that can be used on every armature being manufactured on an armature manufacturing line, as well as apparatus for performing that test, are provided. The armature is immersed in an acoustic coupling medium. Acoustic pulses, preferably ultrasonic pulses, are beamed onto the commutator tang/wire interface region of a commutator tang/bar fused joint or the fused joint itself and an acoustic signature is measured. The quality of the joint can be determined by comparing the acoustic signature to a predetermined acoustic signature of known quality. A testing station on an armature production line includes a mechanism for removing the armature from the production line, immersing it in the coupling medium, and rotating it as each joint in the commutator of that armature is checked.

Abstract: In an ultrasonic inspection apparatus for detecting a flaw present in a target object (2) on the basis of an echo signal (b) from the target object (2), a high-frequency echo signal (b) output from an ultrasonic transmit-receive unit (1) is A/D-converted at a high sampling frequency (f.sub.S) in only a predetermined measurement time interval (T.sub.M) in a repetitive period (T.sub.O) of an ultrasonic pulse (a) and is temporarily stored in a storage unit (12). Thereafter, the sampling data is read out at a read frequency (f.sub.R) lower than the sampling frequency (f.sub.S). A digital signal process for noise reduction using a first digital filter (18) or a synchronous adding/averaging circuit (27) is performed to only data in the measurement time interval (T.sub.M). As a result, noise included in the echo signal (b) is considerably reduced while on-line inspection is kept performed.

Abstract: A sheet material detector has an ultrasonic transmitter and an ultrasonic receiver spaced from one another to permit the passage of a sheet of material therebetween in use. The transmitter and the receiver are mounted on a support to transmit and receive the ultrasonic beam respectively along an axis which is at an acute angle, preferably in the range from 50.degree. to 70.degree., in relation to the plane of the sheet material in use, and each of the transmitter and the receiver includes a hood for shielding the ultrasonic beam against contamination by stray sound waves reflected from extraneous bodies or at the surface of the web or sheet. The detector also includes output signal responsive to the received ultrasonic beam for generating an output signal. One application of the detector is in splice detecting apparatus for detecting the presence of splices in a web of material, and another application is in edge detecting apparatus for indicating the position of an edge of the web or sheet of material.

Abstract: An apparatus for detecting breakage of a web of material traversing a machine for feeding the web, and a method for the same. The apparatus includes a housing for mounting three transducers, a first transducer adapted to periodically emit a burst of energy for a period of time, the burst of energy being reflected off an object and producing an echo signal. A second transducer adjacent to the first transducer receives a portion of the echo signal, and a third transducer also adjacent to the first transducer receives another portion of the echo signal. The strongest portion of the echo signal is used to detect whether the web is broken.

Abstract: An apparatus and method are disclosed for producing acoustical reflected images from selected planes within an integrated circuit package to detect flaws within the package.