Abstract: The present invention relates to methods for non-destructive testing of a weld joint of a bolt (8) welded onto a contact area (4) on a planar sheet metal (6), more specifically a stud bolt welded on using the lift ignition method, wherein during the welding operation a weld pool (10) having a modified material structure is formed beneath said contact area (4), said method using directed ultrasonic signals and comprising the following operational steps: transmitting of ultrasonic signals into said sheet metal (6) using a directing and obliquely transmitting ultrasonic transmitter (1) at a coupling-in point (A), coupling out of the ultrasonic signals transmitted through said sheet metal (6) at a coupling-out point (B) by means of an ultrasonic receiver (2), wherein said coupling-out point (B) is located on the acoustic path of undisturbed signal spreading of the ultrasonic signals transmitted into said sheet metal (6), wherein the acoustic path of undisturbed signal spreading of the ultrasonic signals transmitt

Abstract: A method and apparatus for measuring the properties, such as permeability, of the rock surrounding a metal cased borehole by generating a seismic or sonic shock downhole within the borehole which is propagated into the surrounding formation where it generates an electrokinetic signal which is detected by measuring the potential between at least two space apart electrodes in contact with the casing.

Abstract: In an ultrasonic transceiver, an inner housing has a bottom portion, a first tubular side wall extending from one end surface of the bottom portion and a first flange portion formed on an outer peripheral portion of the first tubular side wall. The bottom portion and first tubular side wall provide a tubular cavity formed therebetween, and the piezoelectric member is mounted on the one end surface of the bottom portion in the tubular cavity. An outer housing has a second tubular side wall coaxially arranged around the outer peripheral portion of the first tubular side wall with a predetermined gap therebetween. The second tubular side wall is provided with one end portion which is opposite to one end surface of the first flange portion and contacted thereto. A first absorption member is inserted in the gap between the first tubular side wall and the second tubular side wall.

Abstract: A hand-held Variable Angle Membrane (VAM) ultrasonic scanning head consisting of transmitting and receiving transducers is used to excite guided waves to detect corrosion, MIC and foreign objects in containers such as pipes. The scanning head includes transducers mounted on a fluid filled housing sealed by a membrane. This system couples ultrasound from the transducer to the pipe wall. The transducer housings are mounted in a rigid frame that holds the ultrasonic transducer housings a specific distance apart and allows each transducer housing to rotate about a pivot point. The membrane deforms to the pipe diameter to be scanned. The scanning head is adjusted to perform inspections in various container diameters and thicknesses. Once adjusted for diameter and thickness, the operator places the scanning head on the pipe and couples the rubber membranes to the pipe with a small amount of couplant.

Abstract: The invention concerns an ultrasonic sensor with a pot-shaped diaphragm having an oscillatory diaphragm bottom and a diaphragm wall which surrounds at least sections of the diaphragm bottom. The invention is characterized in that at least sections of the diaphragm wall have a foam-like structure.

Abstract: The present invention provides an ultrasonic probe and method for making the same is provided which has an advantageous construction and method of assembly. The ultrasonic probe has a segmented ultrasonic transducer having a plurality of individual independent transducers, a plurality of piezoelectric transducers connected to a first end of a respective individual independent transducer; and a plurality of electrical connections electrically communicating each the piezoelectric transducer with a power source.

Abstract: The system provides a means for identifying the opposite ends of each particular conduit of an array of conduits laidout in a building. The system includes a sonic transmitter and a sonic receiver which are units that are separate from each other and portable. The transmitter is connected to a sonic output transducer mounted on a wand which semi-rigid allowing it to be placed at an open end of a conduit and emit a sonic signal thereinto and through the conduit. The receiver is connected to sonic input transducer mounted on another wand which is semi-rigid allowing it to be placed at the opposite open end of the conduit and receive the sonic signal transmitted through the conduit. The sonic transducers may be moved from one of the open ends to another in the array until the input transducer receives the transmitted signal.

Abstract: The invention relates to an Ultrasound Sensor, especially for a vehicle and the passenger compartment thereof, comprising a can-shaped housing, a housing base, a housing closure and a sensor element arranged at the base inside the housing, and in the area of the housing closure there is arranged a contact device which is attachable, in locally fixed fashion, inside housing; the contact device presenting, in the direction of the longitudinal axis, a penetrating recess and being connected, in electrically conductive fashion, in at least one contact point with at least one electrode of the sensor element by means of thick-stranded wire. The invention also relates to a method for producing the Ultrasound Sensor.

Abstract: A dynamically configurable ultrasound transducer element and related circuits and methods. The transducer may comprise an array of capacitive transducer elements, a row decoder coupled to said array of capacitive transducer elements, a column decoder coupled to said array of capacitive transducer elements, a bias voltage source coupled to said row decoder, and a driving signal source coupled to said column decoder. Preferably, a master clock also is provided to allow for a synchronization of signals between the row decoder and column decoder.

Abstract: An ultrasound transducer array (408) includes at least one transducer element (412) having a first (604) and second (606) portions separated by an acoustical discontinuity (520). The first portion (604) has the desired length to form a half-wave k31 resonance, while the second portion (606) has a resonant length for an undesired very low frequency out-of-band k31 resonance. The thickness of the transducer element (412) is designed for k33 half-resonance. Given the design, the transducer element (412) can operate and provide for both forward-looking (514) and side looking (512) elevation apertures. A method is also disclosed for using the disclosed ultrasound transducer (412) in ultrasound imaging.

Abstract: An end effector for supporting an ultrasonic testing probe on a robot arm having a robot mounting bracket for use in a nuclear reactor pressure vessel. The end effector has a wrist assembly with a rotatable wrist axle. The wrist assembly is coupled to the robot mounting bracket and a probe assembly is coupled to the wrist shaft. The ultrasonic testing probe is floatably disposed within the probe assembly.

Abstract: A method for quality control testing of a laser shock peening process of a production workpiece includes (a) ultrasonically scanning at least a portion of a laser shock peened surface on the workpiece wherein a region having deep compressive residual stresses imparted by the laser shock peening process extends into the workpiece from the laser shock peened surface, (b) digitizing a signal derived from the scanning and forming a digitized image of intensity values from the scanning, (c) calculating at least one statistical function value for a plurality of points of the digitized image of the workpiece based on the intensity values, and (d) comparing the statistical function value to a pass or fail criteria for quality assurance of the laser shock peening process or accepting or rejecting the workpiece.

Abstract: The present invention provides a mounting assembly, for use with an ultrasound transducer attached to an ultrasound machine, for determining the spacial relationship between a succession of 2D image slices of a target of a subject, generated by the ultrasound machine. The mounting assembly comprises: (i) means to mount an ultrasound transducer; (ii) means to engage a surface of the subject in the proximity of the target, the means to engage a surface being moveably attached to the means to mount an ultrasound transducer; and (iii) sensing means, in communication with the means to engage a surface, to measure the movement of the means to engage a surface during acquisition of the succession of 2D image slices. Preferably, the sensing means comprises a tilt sensor and a displacement sensor.

Abstract: An ultrasonic transducer has a pot-like housing with an annular wall and with a bottom surface serving as diaphragm. A piezo-element which is connected with connection lines is arranged at the inner side of the bottom surface. The edge remote of the bottom surface is surrounded by a decoupling ring which is formed as a holder for the connection lines.

Abstract: Ultrasonic techniques are applied to the measurement of wooden members to detect splitting during sawing operations and thereby allow modification of a sawing technique or change in saw cut placement.

Abstract: Vibration transducer unit for converting vibrations to electric signals, in which unit there is a transducer part (11) and a signal processing part (14), like a preamplifier part. The transducer part (11) and the signal processing part (14) are integrated to a single structure.

Abstract: Method, apparatus and computer programs are described for compensating for the effect of temperature on the sensitivity of electrostatic ultrasound (US) transducers, particularly as used in an automotive occupancy sensing (AOS) systems for sensing the nature or type of occupant and the location of the occupant with respect to the vehicle interior. The invention permits the AOS to classify the occupancy state of the vehicle from a US echo signal substantially free of the effects of temperature on signal amplitude. A capacitive divider or voltage monitor is employed to measure the capacitance of the transducer. The voltage monitor output is used by the scaling algorithm of a compensator to determine the scaling factor to be applied to the US transducer signal to compensate for the effect of temperature on the transducer sensitivity.

Abstract: An acoustic impedance measuring apparatus emits ultrasonic waves to a target measurement object and measures the acoustic impedance of the target measurement object by ultrasonic waves fed back from the target measurement object. This acoustic impedance measuring apparatus includes an ultrasonic transducer, pulse signal generator, signal separator, frequency converter, parameter extractor, and acoustic impedance calculator. The pulse signal generator generates a pulse signal to be applied to the ultrasonic transducer. The signal separator separates, from an output from the ultrasonic transducer, an immediate ultrasonic response signal resulting from ultrasonic waves reflected by the surface of the target measurement object. The frequency converter obtains the frequency characteristics of the immediate ultrasonic response signal. The parameter extractor extracts predetermined parameters from the frequency characteristics.

Abstract: The invention concerns a monitor head for ultrasound control by pulse echo process, in particular for producing a brief ultrasound pulse, unipolar as far as possible, comprising an oscillator/transmitter (26) and an oscillator/receiver (32), each provided with electrodes (28, 30, 34, 36). The oscillator/transmitter (26) and the oscillator/receiver (32) are made of the same material. The oscillator/transmitter (26) and the oscillator/receiver (32) are arranged directly one behind the other, in the sound propagation direction, in particular flat-bonded one on the other.

Abstract: An ultrasonic transducer (10) comprises a housing (12) having an axis (52) and a diaphragm (60) centered on the axis (52) at one end (62) of the housing (12). A cylindrical vibratable mass (74) is disposed in the housing (12) and centered on the axis (52). The vibratable mass (74) has a first end (76) secured to and centered relative to an inner surface (80) of the diaphragm (60) and an opposite second end (84). The vibratable mass (74) can be vibrated in a direction along the axis (52). A second cylindrical mass (90) is disposed in the housing (12) and centered on the axis (52). The second mass (90) has a third end (92) with a recess (100) centered on the axis (52). The second end (84) of the vibratable mass (74) extends into the recess (100) and is secured to the second mass (90). The second mass (90) resists the vibration of the vibratable mass (74) toward the second mass (90). An electrode (110) is fixed to a fourth end (94) of the second mass (90) opposite the third end (92).

Abstract: A portable digital ultrasonic monitoring system and method for use by an operator in detecting the ultrasonic waves and temperature variations produced by sources such as leaks in pipes, arcing, electrical corona and machinery defects is provided. The digital ultrasonic monitoring system includes a microprocessor based system in a hand held elongate housing that digitally analyzes and stores information received from its sensors. The digital ultrasonic monitoring system provides a referenced decibel output reading of the signal strength of the received ultrasonic signals. In addition, a heterodyned type audio signal that is related to the sensed ultrasonic signals is provided to the operator through a pair of headphones. The portable device has user input keys that allow the operator to select from a variety of different operating modes. A display displays a variety of different readings depending upon the operating mode of the device.

Abstract: An ultrasonic inspection element and method of fabrication are provided for ultrasonic inspection of curved surface parts. Various points on a transducer are located. These points include the location where a ray starts, to the desired focal point in the material being inspected. The path of the ray is through a water medium and a water-metal boundary. These points are fitted onto a cylindrical surface. The ray is back propagated until it is focused at the desired focal point.

Abstract: A shoe for ultrasonically inspecting an area beneath the fillets of a crankshaft and the area adjacent each side of the fillets for flaws in the highly stressed fillet area, the shoe comprising a planar surface and a cylindrical surface disposed at a right angle thereto with a toroidal surface forming an smooth transition therebetween and mating with surfaces on the crankshaft, the shoe houses three transducer oriented toward the centerline of the cylindrical surface and disposed to generally form angles of 22.5.degree., 45.degree. and 67.5.degree. with the centerline of the cylindrical surface, the transducer oriented at 45.degree.

Abstract: A wide bandwidth, ultrasonic transducer to generate nondispersive, extensional, pulsed acoustic pressure waves into concrete reinforced rods and tendons. The wave propagation distance is limited to double the length of the rod. The transducer acoustic impedance is matched to the rod impedance for maximum transfer of acoustic energy. The efficiency of the transducer is approximately 60 percent, depending upon the type of active elements used in the transducer. The transducer input energy is, for example, approximately 1 mJ. Ultrasonic reflections will occur at points along the rod where there are changes of one percent of a wavelength in the rod diameter. A reduction in the rod diameter will reflect a phase reversed echo, as compared with the reflection from an incremental increase in diameter. Echo signal processing of the stored waveform permits a reconstruction of those echoes into an image of the rod.

Abstract: An electronic circuit serving as an interface between a piezoelectric transducer and a circuit for processing a measuring signal provided by said transducer, said electronic interface circuit serving for providing a constant direct current to said piezoelectric transducer, and for pre-processing an electric signal provided by the transducer via a voltage modulator, said electronic interface circuit being connected to said voltage modulator by a cable having two terminals at each end, the two terminals at a first end of the cable being connected to the output of the voltage modulator and the two terminals at a second end of the cable being connected to said electronic interface circuit.

Abstract: A short ring is mounted onto a back part of a housing of an ultrasonic sensor so that the short ring is coaxial with the housing. The width of the short ring along the axial direction of the housing is set such that it shields the back part of the housing including a transformer of a processor. The short ring is made up of an excellent metal conductor and is coaxial with the coils of the transformer.

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: A method is disclosed for selecting characteristics (i.e. thickness-frequency product, length and material) of leakage plates used in ultrasonic transducers that transfer ultrasonic energy via leakage to fluid media with low acoustic impedances. High leakage efficiency and wide bandwidths are achieved by exciting the low order antisymmetric Lamb wave mode (A0) at the selected frequency in the leakage plate. Various actuator configurations that can be used to excite and detect the A0 mode in the leakage plate are described. Some embodiments employ reflector structures to intercept the leaky waves and reform them into beams normal to the plane of the leakage plate.

Abstract: Method and apparatus for ultrasonic inspection of an object. A tire is mounted for rolling along the surface of the object. It contains a liquid and a transducer assembly. The transducer assembly is positioned in the tire adjacent a portion of the surface of the tire in contact with the object. The liquid and the surface of the tire in contact with the object provide an acoustic bridge between the transducer assembly and the object. An electric signal processing system is connected to the transducer assembly. It generates electric signals which are converted to acoustic signals in the transducer assembly to place acoustic signals in the object. Acoustic signals returned from the object are converted to electric signals by the transducer assembly, and are processed in the electric signal processing system to indicate flaws in the object.

Abstract: A waveguide couples ultrasonic energy from a source on one side of a fluid-bounding wall, such as a conduit, into fluid on the other side of the wall. The waveguide has a buffer that couples to the source, and a seat with an exit face, while an intermediate portion contains a redirecting surface for internally redirecting energy propagated along the buffer toward the exit face to exit as a narrow directed beam. The waveguide core has a rectangular cross section which is narrow, i.e., has an aspect ratio above two and preferably above three or four, while the buffer has a length effective to thermally isolate or protect the source from the conduit. The waveguide attaches easily, either as a clamp-on or welded unit, to a pipe or spoolpiece, allowing local fabrication of massive or custom flow cells, such as large spoolpieces with Gauss-Chebyshev interrogation paths. Several guides may be positioned in an array to cover interrogation paths for an extended range of sound speeds or flow rates.

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: A method of making a pressure sensor or acoustic transducer having high sensitivity and reduced size. A thin sensing diaphragm is produced by growing a single crystal, highly doped silicon layer on a substrate using a chemical vapor deposition process. The diaphragm is incorporated into a pressure sensor or acoustic transducer which detects pressure variations by a change in the capacitance of a capacitor which includes the diaphragm as a movable member. The thin diaphragm produces a highly sensitive device which can be fabricated in a smaller size than sensors or transducers having thicker diaphragms.

Abstract: An ultrasonic sensor has a built-in temperature compensation capacitor housed in a casing and facilitates an inside-the-casing lead-wire bonding connection process and a connection verifying process while increasing reliability. The ultrasonic sensor is provided with a piezoelectric vibration element and a capacitor for temperature compensation capacitor both housed in a casing. The temperature compensation capacitor includes a pair of electrodes located on one common surface of a dielectric body thus allowing the ultrasonic sensor to be electrically connected to lead wires on the one common surface.

Abstract: An optoacoustic system comprises an optoacoustic transducer including a first array of acoustic transducers and a second array of optical fibers; an acoustic subsystem for controllably exciting at least a first subset of the acoustic transducers to generate acoustic pulses with a prescribed pulse width, and for forming a first image based on return acoustic pulses reflected from a patient; an optical subsystem for controllably generating optical pulses to be transmitted through at least a first subset of the optical fibers toward the patient, and for forming a second image based on light reflected from the patient; and image correlation means for correlating the first and second images. The first and second arrays may take various forms, including the form of an annular array in which the acoustic transducers are arranged coaxially and the optical fibers are disposed around an outer periphery of the first array. The first and second arrays may also take the form of linear arrays.

Abstract: A composite probe apparatus exhibiting a high performance and a high efficiency in detecting internal defects of a steel pipe or a steel plate, coupled with offering a stable sensitivity and covering a wide range for flaw detection. A plurality of reception oscillators PR1 to PR4 are disposed in a zigzag fashion in both sides of a transmission oscillator PT. The length l T of the transmission oscillator PT is determined such that a near sound field is established over the entire measuring range, while the width WT of the transmission oscillator PT is determined such that a far sound field takes place over the entire measuring range. The transmission and reception oscillators are constructed with a common piezoelectric plate an electrode of which undergoes division.

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: A microelectromechanical sensor for detecting acoustic signals propagating through the ground, including reflected signals, has a cantilever provided with capacitance measurement to detect deflection or twisting of the cantilever due to the presence of acoustic signals. The cantilever size and shape may be changed to increase sensitivity to a particular frequency. An array of sensors may be used to detect buried objects, such as land mines.

Abstract: A two-dimensional ultrasonic transducer for forming images. The transducer has a plurality of transducer elements for producing ultrasonic bursts in a predetermined manner, and receiving reflected ultrasound from the subject under examination due to the ultrasonic bursts. The plurality of transducer elements are arranged in an array into columns and rows, the columns of the transducer elements arranged in a scanning plane for scanning the subject under examination in order to form a two-dimensional profile of the subject, and the rows of the transducer elements having groups of symmetrically arranged transducer elements being oriented in a elevational plane. Each of the groups of symmetrically arranged transducer elements are mechanically arranged to have a focus at specified locations distant from the transducer which is within the subject under examination.

Abstract: Method and apparatus for monitoring curing in a resin. Acoustic, ultrasonic waves are propagated through a waveguide disposed through a quantity of resin while the resin is curing. The waves are transmitted and received by transducers arranged in an acousto-ultrasonic configuration with respect to a flexible waveguide. The waveguide may be made from bundled fibers. The velocity or amplitude of the acoustic waves is affected by the physical characteristics of the resin sample. Monitoring changes in the speed or amplitude of the propagated waves permits changes in the resin to be monitored in real time. Only a small sample quantity of resin need be employed.

Abstract: An ultrasonic transducer is disclosed for emitting an ultrasonic wave radially inward. The transducer is constructed with a strip of piezoelectric material laminated with a pair of electrically conductive metal layers that are conductively isolated from one another. In a preferred embodiment, the strip of piezoelectric material is formed in a cylindrical shape and with continuous sinusoidal ripples along the circumference. The sinusoidal ripples are designed to emit a specific wave length of a desired frequency. The radius of the sinusoidal wave is based on material characteristics and the desired resonance frequency. The invention discloses various methods and apparatus for constructing and maintaining the transducer sinusoidal shape. One method includes attachment of a pair of rigid end caps on the laminated piezoelectric material, and another discloses weaving the laminated piezoelectric material through a nonconductive mesh cage, and yet another includes adhesively attaching the transducer to a housing.

Abstract: In an ultrasonic inspection apparatus, a piezoelectric element having a first resonant frequency is stuck to a complex resonance member having a second resonant frequency. The second resonant frequency is determined with a conversion in terms of half wavelength. A resultant ultrasonic probe transmits/receives ultrasonic waves of the first resonant frequency and a plurality of other frequencies. In constructing an ultrasonic tomographic image of the object to be inspected from a received signal obtained by using the ultrasonic probe, the imaging frequency is changed according to the depth in the object to be inspected.

Abstract: The present invention is directed to a blown film extrusion apparatus in which film is extruded as a tube from an annular die and then pulled along a predetermined path. The improved blown film extrusion apparatus includes a system for gauging and controlling the surface of the extruded film tube, which includes a number of components which cooperate together. At least one transducer is provided and positioned adjacent the extruded film tube for transmitting interrogating pulses to, and receiving interrogating pulses from, the extruded film tube, and for producing a signal corresponding to a detected position of the extruded film tube. A control system is provided for substituting a filtered position signal derived from a dynamic filtering process in lieu of the detected position signal. An air flow controller is provided for varying a quantity of air within the extruded film tube in response to the control system for urging the extruded film tube to a desired position.

Abstract: A device for the detection of smooth surface lesions of dental caries on a tooth crown surface, having an ultrasonic transducer for transmitting ultrasonic waves and receiving ultrasonic wave reflections produced by lesions present on the surface, and an interface operatively connected to the transducer. The interface has a contact surface forming an angle .alpha. with a longitudinal axis of the ultrasonic transducer, where .alpha. is substantially different from 90.degree.. When the contact surface is in at least partial contact with a tooth crown surface at the longitudinal axis, ultrasonic waves generated by the ultrasonic transducer are imparted by the interface onto the tooth crown surface as surface ultrasonic waves which migrate along the tooth crown surface. Any lesions present on the tooth crown surface are then identifiable as surface ultrasonic wave reflections produced thereat.

Abstract: An ultrasonic sensor for performing sensing a spatial area and/or measuring ontactless a distance has at least one ultrasonic transducer for sending ultrasonic impulses and/or receiving the echo of the ultrasonic impulses. A device for concentrating the energy of the ultrasonic impulses onto a spatial area to be sensed and for concentrating the energy of the echo of the ultrasonic impulses onto the at least one ultrasonic transducer is provided. The device for concentrating the energy has a reflector with a reflective surface. The reflective surface has parabolic surfaces of second order. The reflector comprises reflector segments that are rigidly or movably connected to one another. A first and second reflector segments are outer segments having reflective surfaces that are paraboloid segments of 50.degree. to 120.degree. of a paraboloid of revolution with a first focal point.

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: 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 surface acoustic wave position-sensing device comprising a piezoelectric substrate, a nonpiezoelectric plate, two surface acoustic wave transducing units and a controlling system connected with the units. Each unit consists of interdigital transducers (IDTs). The thickness of the piezoelectric substrate is larger than three time an interdigital periodicity of the IDTs. The thickness of the nonpiezoelectric plate is smaller than the interdigital periodicity. Each of the IDTs is placed such that the finger direction thereof is slanting to that of the IDTs by an angle .alpha.. When an electric signal is applied to each of the IDTs a SAW is excited on an area, and transmitted to an area, in contact with the IDTs of the upper end surface of the piezoelectric substrate through the nonpiezoelectric plate. The controlling system senses a touch with a finger by the generation of the electric signal at one of the interdigital transducers.

Abstract: In a method and an apparatus for exciting acoustic waves, the surface of an object is irradiated with coherent parallel energy beams and coherent focusing energy beams which have different frequencies in such a manner that they overlap each other to generate interference fringes (concentric circles) propagating from outside to the inside at propagation speed which is higher than a specific acoustic speed of the object. The acoustic waves are excited in accordance with distortion distribution generated in the surface of the object attributable to the photo-thermal effect of the interference fringes, the acoustic waves being focused to a small region in the object, the position of which is determined by the specific acoustic speed of the object and the propagation speed of the interference fringes.

Abstract: A sealing quality tester and a control method therefor includes an ultrasonic transmitter, a power supply, a charging detector, an ultrasonic oscillator and an ultrasonic generator; and an ultrasonic receiver. The ultrasonic receiver includes an ultrasonic signal detector, an A/D converting unit, a controller, a power supply, a key input unit, a sound generator and a liquid crystal display.

Abstract: An ultrasonic probe includes an ultrasonic transducer; a delay line acoustically coupled to said transducer so that ultrasonic vibrations may be transmitted into said delay line from said ultrasonic transducer in a first direction, said delay line includes a first section and a second section; the first and second sections forming an interface that is substantially perpendicular to said first direction; and the second section including a surface for coupling with a material to be investigated. The probe can be used to measure a thickness of a coating on a substrate by transmitting a signal in a first direction from the transducer into the delay line; measuring a time t.sub.1 for a first portion of the signal to travel round trip from the transducer and the interface; using the measured time t.sub.1 to calculate an expected time t.sub.2 for a second portion of the signal to travel round trip from the transducer to an opposite face of the delay line; measuring a time t.sub.