Abstract: A vibrometer may measure acoustic responses in portions of a structure along a scan path to acoustic excitation of the structure. A ranging device may measure distances to the portions of the structure along the scan path. A three-dimensional point cloud may be generated based on the acoustic responses in the portions of the structure and the distances to the portions of the structure. The three-dimensional point cloud may include points representing geometry of the portions of the structure. The points may be associated with the acoustic responses in corresponding portions of the structure. One or more properties of the structure may be determined based on an analysis of the three-dimensional point cloud.

Abstract: Methods and systems for solving inverse problems arising in systems described by a physics-based forward propagation model use a Bayesian approach to model the uncertainty in the realization of model parameters. A Generative Adversarial Network (“GAN”) architecture along with heuristics and statistical learning is used. This results in a more reliable point estimate of the desired model parameters. In some embodiments, the disclosed methodology may be applied to automatic inversion of physics-based modeling of pipelines.

Abstract: Some implementations of the disclosure are directed to an ultrasound measurement device including: multiple ultrasound sensors to capture tomographical information of a physiological structure, each ultrasound sensor comprising a transducer having a respective resonant frequency, where each transducer has a frequency response that partially overlaps with a frequency response of another transducer; and a processing device to control and process measurements made by the ultrasound sensors. The device may be incorporated in an adhesive substrate configured to be adhered to a patient's skin in alignment with an artery of the patient.

Abstract: A method and ultrasound imaging system for detecting a coherent reflector includes acquiring ultrasound channel data from a volume with a probe, calculating a transform function from the ultrasound channel data, identifying a first angle of a projection of the coherent reflector in a plane parallel to the 2D aperture based on the transform function, detecting a line-shaped echo pattern in the ultrasound channel data, and determining a second angle of the coherent reflector with respect to the 2D aperture based on the position of the line-shaped echo pattern. The method and system includes determining a position and orientation of the coherent reflector based on the first angle and the second angle, enhancing a representation of the coherent reflector in an image generated based on the ultrasound channel data, and displaying the image on a display device after enhancing the representation of the coherent reflector.

Abstract: A method for determining an electrical property of interest of material(s) in a target region confined by a boundary surface comprises receiving measured values of a measurable electrical quantity; providing simulated values of the measurable electrical quantity for an initial approximation of the electrical property conditions; determining an objective function comprising observation difference between the measured and the simulated values as well a prior model, and determining an adjusted approximation; and providing, on the basis of the adjusted approximation, an estimation of the electrical property of interest. Simulated statistics of a position deviation in the observations is provided, caused by a difference of an effective position of the measurement probe from a predetermined reference position; and by providing the observation model to define the observations of the measurable electrical quantity to correspond to measurements made with the measurement probe in the reference position.

Abstract: An apparatus for measuring normal and shear stress at a surface. The apparatus includes a substrate; and a plurality of sensing units on the substrate. Each sensing unit includes a mechanical transducer having a receiving surface and a sensing surface; and a plurality of normal force sensors between the sensing surface and the substrate.

Abstract: A bolt axial force measurement apparatus of the present invention includes an echo detection section and an axial force calculation section. The echo detection section sets a head echo gate for the head echo and sets a bottom echo gate for the bottom echo, and executes tracking for a plurality of ultrasonic pulses emitted during tightening of the bolt so that the head echo gate and bottom echo gate are shifted independently to include the predetermined positions at the same position in the head echo gate and bottom echo gate.

Abstract: This application discloses integrated probes and probe systems, which can be attached to the robotic arms of a remotely operated vehicle to perform both cathodic protection (CP) voltage measurements and ultrasonic testing (UT) thickness measurements at an underwater surface. In some embodiments, the integrated probe system couples an inner and outer gimbal together such that one or more electrically conductive legs pass from the outer gimbal through the inner gimbal. These legs are arranged about an ultrasonic sensor which extends from the front surface of the inner gimbal. When the integrated probe contacts the underwater surface, both the ultrasonic sensor and at least one leg contact the surface, thereby providing substantially simultaneous CP and UT measurements.

Abstract: A method and ultrasound imaging system for detecting a coherent reflector comprises acquiring ultrasound channel data from a volume with a probe including a 2D aperture, calculating a MRT from the ultrasound channel data, identifying a first angle of a projection of the coherent reflector in a plane parallel to the 2D aperture based on the MRT, detecting a line-shaped echo pattern in the ultrasound channel data, determining a second angle of the coherent reflector with respect to the 2D aperture, determining a position and an orientation of the coherent reflector based on the first angle and the second angle, enhancing a representation of the coherent reflector in an image generated based on the ultrasound channel data, and displaying the image on a display device after enhancing the representation of the coherent reflector.

Abstract: A respective sensing region of at least one radar unit is oriented into a passenger compartment of the motor vehicle and a control device is configured to sense a position of a body part of a person and/or a movement of the body part in the passenger compartment on the basis of the reflection respectively received by the at least one radar unit, thus providing non-contact detection of the body part of the person in the motor vehicle. As viewed from the passenger compartment, the at least one radar unit can be arranged behind a display surface of a display device or alongside the display surface of the display device.

Abstract: Exposure to ultrasound energy emitted by remote object detection systems on vehicles is reduced for vehicle occupants. An automotive vehicle has a passenger cabin and a remote sensing system including ultrasonic transceivers mounted for sensing external objects. An ultrasonic microphone is disposed to sense an ultrasonic wave entering the passenger cabin at greater than 30 kHz. An antinoise processor calculates an antinoise signal adapted to at least partially cancel the ultrasonic wave at a predetermined location in the cabin. An amplifier is coupled to the processor for amplifying the antinoise signal by a predetermined gain. An ultrasonic speaker is coupled to the amplifier to project the antinoise signal into the predetermined location to attenuate the ultrasonic wave at the predetermined location.

Abstract: An ultrasonic flow meter including a meter housing, a flow tube with an inner flow channel for a fluid to be measured, and ultrasound reflectors, the meter housing has two transducer recesses, an ultrasound transducer positioned in the first transducer recess, and a second ultrasound transducer positioned in the second transducer recess. The transducer recesses each has slanted bottom walls, with the ultrasound transducers abutted against the slanted bottom walls of the recesses.

Abstract: An electronic device comprises a CMOS substrate having a first surface and a second surface opposite the first surface. A plurality of ultrasonic transducers is provided having a transmit/receive surface. A contact surface is piezoelectrically associated with the plurality of ultrasonic transducers and is formed on the first surface of the CMOS substrate. The plurality of ultrasonic transducers is disposed on the second surface of the CMOS substrate, with the transmit/receive side attached to the second surface thereof such that the CMOS substrate is between the plurality of ultrasonic transducers and the platen. An image sensing system is also provided, together with a method for ultrasonic sensing in the electronic device.

Abstract: A fluid level sensor may include a first sound transducer, a second sound transducer, a reference element, a first deflection element, and a control unit. The reference element may be disposed at a predetermined distance from the second sound transducer and arranged in a fluid space of the fluid container. The first deflection element may be arranged in the fluid space to deflect the second sound signals by a first predetermined angle toward the fluid surface. The control unit may establish a speed of sound within a fluid in the fluid space based at least in part on the second sound signals and establish the level of the fluid surface over a base portion of the fluid container based at least in part on the first sound signals, the second sound signals, and the speed of sound within the fluid.

Abstract: A monitoring system comprising ultrasound sensors to monitor the structure of a composite material part during production is automatically calibrated using reference sensors mounted on reference blocks and placed in the production environment of the part. The automatic calibration comprises actuating a reference sensor to transmit an ultrasonic wave and measuring the amplitude of a reference echo constituted by the transmitted ultrasonic wave after it has passed through the reference block. The measured amplitude is compared to a set point value and the gain is applied to the reference sensor to obtain an amplitude value of the reference echo substantially equal to the set point value. The gain applied to the reference sensor is applied to the ultrasound sensors of the same type as the reference sensor. The operation is performed for each reference sensor, and successively for all of the stages of production of the part.

Abstract: The invention relates to novel processes for determining the quality of an uncrosslinked rubber mixture by means of ultrasound and to an apparatus suitable for this purpose.

Abstract: The present invention is related to a sensor for simultaneously measuring both normal and shear forces applied to the sensor, and further a statically responsive sensor for measuring shear forces. The present invention further includes a method of designing an object or a device using these sensors.

Abstract: A spatial position x? of each ultrasonic transducer is accurately obtained for each probe in consideration of each edge transducer gap, and a delay time T(x?(n)) and a weighting coefficient W(x?(n)) are calculated on the basis of the position of each ultrasonic transducer. A control unit executes ultrasonic transmission/reception by using the calculated delay times and weighting coefficients to realize a suitable acoustic field with high deflection angle accuracy, small sidelobes, and the like as compared with the prior art.

Abstract: A method for notifying a user of the status of a parking space. The method comprises transmitting a pulse from a transceiver assigned to a parking space and for each pulse receiving by transceiver a corresponding echo created by said pulse being reflecting back from a object occupying said parking space. The method further comprises measuring corresponding echo time by a processing unit. The method further comprises comparing said corresponding echo time to a predefined range of echo times by a processing unit to determine occupancy of said parking space. The method further comprises using said occupancy of parking space to determine the parking space status by a processing unit, together with information on time of day and parking space permission. The method further comprises notifying a user of said parking space status by visual indication from at least one light emitting diode array.

Abstract: An apparatus for determining a fluid's kinematic viscosity from ultrasonic energy that has passed through the fluid of unknown viscosity along an acoustic path of known length. A computer of the apparatus determines a characteristic frequency of a received electrical signal associated with the ultrasonic energy and measures the fluid's velocity of sound. The kinematic viscosity of the fluid is determined by the computer on a continuous basis based on the characteristic frequency and the sound velocity. A method for determining a fluid's kinematic viscosity.

Abstract: According to one embodiment, an ultrasonic diagnosis apparatus includes an ultrasonic probe, an ultrasonic transmission/reception unit which generates echo signals associated with scan planes by transmitting and receiving ultrasonic waves to and from an object via the ultrasonic probe, an image data generating unit which generate tomogram data respectively corresponding to the scan planes based on the echo signals, a contour line extraction processing unit which extracts contour lines of a specific region from the plurality of tomograms, a contour line processing unit which generates curves respectively corresponding to the extracted contour lines, and a surface image generating unit which generates one-dimensional brightness trains on the curves from the tomograms and generates a surface image expressing the surface unevenness of the specific region with brightness changes by arraying the brightness trains in accordance with the positions of the corresponding scan planes.

Abstract: An ultrasonic detection method and system are disclosed. The ultrasonic detection method includes providing an ultrasonic detection system having a first ultrasonic device arrangement and a second ultrasonic device arrangement, positioning the ultrasonic detection system in a peripheral offset position with respect to an object to be measured, and transmitting and receiving an ultrasonic beam between the first ultrasonic device arrangement and the second ultrasonic device arrangement, thereby obtaining ultrasonic detection information about the object. Additionally or alternatively, the transmitting and receiving of the ultrasonic detection method obtains data on a volume greater than that which is capable of being analyzed by a single probe arrangement. The ultrasonic detection system includes the first ultrasonic device arrangement and the second ultrasonic device arrangement positioned in a peripheral offset position with respect to an object to be measured.

Abstract: A method and apparatus for inspecting a composite structure. A response sound signal to a sound signal sent into the composite structure at a location on the composite structure is detected. An attenuation is identified in the response sound signal detected in response to the sound signal sent into the composite structure at the location on the composite structure. An indication of whether additional evaluation of the location is needed based on a comparison of the attenuation in the response sound signal to a baseline attenuation value for porosity for the location on the composite structure is generated.

Abstract: Disclosed is an apparatus, method and system for inspecting structures, and more particularly for evaluating the condition of a structure. The disclosed nondestructive inspection testing method and apparatus enables an operator to assess the condition of a structure, such as a composite laminate part and determining the location and depth of anomalies. The method includes generating a subsurface longitudinal ultrasonic wave signal at a high incidence angle into a structure being evaluated and collecting at least one of any front, back or side reflected wave data. The method may include processing the reflected wave data to determine the condition of the structure, including any anomalies that may have been detected and their location, size and shape.

Abstract: Methods and systems for connection to a transducer in ultrasound probes are provided. One connection arrangement includes a connector having a transducer connection portion configured to couple to a transducer of an ultrasound probe and a scan head connection portion configured to extend from a scan head of the ultrasound probe containing the transducer. The transducer connection portion and the scan head connection portion being a single element.

Abstract: An inspection arrangement and an associated method for inspecting an elongate object. The arrangement includes a housing providing an interior space. The housing has an entrance and exit that are aligned. The arrangement includes a plurality of ultrasonic sensor arrays disposed to direct ultrasonic sensory pluses. Each sensor array has a plurality of ultrasonic sensors with each ultrasonic sensor positioned to direct a respective ultrasonic sensory pulse in a respective direction. The arrangement includes a fluid delivery device that delivers a coupling fluid into the interior space. The coupling fluid transmits the ultrasonic sensory pluses to the elongate object. The arrangement includes a plurality of redirecting elements associated with the plurality of ultrasonic sensor arrays. Each redirecting element is positioned such that ultrasonic sensory pluses from the respective ultrasonic sensor array proceed through the respective redirecting element and are redirected along a different direction.

Abstract: An apparatus for inspecting a tubular workpiece may include a probe assembly and a rotation mechanism. The probe assembly may include a transducer array positionable adjacent to an inner surface of the tubular workpiece. The probe assembly may generate transmitted sound waves and may receive reflected sound waves. The rotation mechanism may rotate the probe assembly relative to the tubular workpiece in a manner such that the transducer array passes over the inner surface in a circumferential direction during transmission of the transmitted sound waves.

Abstract: An ultrasonic inspection apparatus includes: an ultrasonic probe apparatus including an ultrasonic transducer; a drive element selecting section that selects a required piezoelectric vibrator of the ultrasonic transducer; a signal detecting circuit that detects an electric signal dependent on a reflected echo of an ultrasonic wave emitted from the selected piezoelectric vibrator; a signal processing section that produces data on an internal image of the inspection object based on the detected reflected echo; a second display unit that combines multiple pieces of image data acquired from the signal processing section and displays an integrated visualization data result; and an second input unit that is used to perform an operation command such as a command input to start or terminate an inspection or an a command to set inspection condition.

Abstract: Frequency-steerable acoustic transducers (FSATs) that allow directional generation or sensing of waves propagating in two-dimensional domains. Directionality is the result of the spatial filtering effect produced by the characteristic shape of the sensing surface. A wavenumber spiral FSAT (WS-FSAT) maps the direction of wave sensing in the [0°, 180°] range to a specific frequency component in the spectrum of the received signal. The use of a wavenumber spiral FSAT operating in sensing mode can be used for the localization of broadband acoustic events. One configuration includes a broadband source generating guided elastic waves in an isotropic plate. The WS-FSAT records the plate response and defines the source location through a time-frequency analysis of the received signal. The frequency selective response of the WS-FSAT directly maps the dominant component of the received signal to the direction of arrival of the incoming wave, thus greatly facilitating the source localization procedure.

Abstract: A method and apparatus for inspecting a test object. A sound signal is sent from a first portion of a curved transducer array through the test object in a direction towards a second portion of the curved transducer array. The curved transducer array has a shape that is configured to cover a non-planar surface of the test object. A response signal in response to the sound signal is received at the second portion of the curved transducer array.

Abstract: Methods and apparatus for inspecting a flaws in tubular disclosed herein include but are not limited to inspection stations comprising one or more chutes adapted to receive a tubular, an inspection assembly adapted to ultrasonically inspect a tubular in the one or more chutes, and one or more rotators for apply directional forces on the tubular to advance and rotate the tubular in the one or more chutes. The inspection assembly is adapted to ultrasonically inspect tubulars while the tubulars are under a rotational force in the chute. The inspection assembly may be further adapted to identify the end of a tubular in a first chute and index the position of the inspection assembly over a second chute to inspect a tubular loaded in the second chute.

Abstract: An ultrasonic diagnostic apparatus having an ultrasonic probe configured to transmit and receive an ultrasonic wave, a transmitter for configured to supply a signal to the ultrasonic probe and forming an ultrasonic beam, a receiver configured to receive a reception signal obtained by transmitting the ultrasonic beam to an object, a signal processor configured to form an ultrasonic image on the basis of the reception signal, a display unit configured to display the ultrasonic image, and a control unit configured to control the transmitter, the receiver, the signal processor and the display unit, comprising a setting unit configured to set an operation mode of the transmitter to a low power consumption operation mode or a high spatial resolution operation mode.

Abstract: The present invention relates to a method of detecting non-linear operation of a measuring device comprising an array of transducers and at least one receiver channel portion. The method comprises receiving measured signals through transducers of the array, processing the measured signals from the transducers through the receiver channel portion, combining the processed measured signals to produce a combined measurement signal, and detecting non-linearity of the combined measurement signal and non-linear operation of the measuring device by detecting saturation of the receiver channel portion. In one embodiment, the receiver channel portion comprises an analog-to-digital converter, a threshold is assigned to a digital output of the analog-to-digital converter, and saturation of the receiver channel portion is detected when the digital output of the analog-to-digital converter oversteps the assigned threshold. In one application of the invention, the measuring device is a non-destructive testing device.

Abstract: Techniques, systems, and devices are described for implementing for implementing computation devices and artificial neurons based on nanoelectromechanical (NEMS) systems. In one aspect, a nanoelectromechanical system (NEMS) based computing element includes: a substrate; two electrodes configured as a first beam structure and a second beam structure positioned in close proximity with each other without contact, wherein the first beam structure is fixed to the substrate and the second beam structure is attached to the substrate while being free to bend under electrostatic force. The first beam structure is kept at a constant voltage while the other voltage varies based on an input signal applied to the NEMS based computing element.

Abstract: An apparatus for inspecting a tubular workpiece may include a probe assembly and a rotation mechanism. The probe assembly may include a transducer array positionable adjacent to an inner surface of the tubular workpiece. The probe assembly may generate transmitted sound waves and may receive reflected sound waves. The rotation mechanism may rotate the probe assembly relative to the tubular workpiece in a manner such that the transducer array passes over the inner surface in a circumferential direction during transmission of the transmitted sound waves.

Abstract: Ultrasonic detection methods are disclosed. The method includes providing an ultrasonic detection system having a transmitting phased array device and a receiving phased array device. A phased array wave is transmitted through a revolutionary body from the transmitting phased array device to the receiving phased array device, thereby obtaining ultrasonic detection information about the revolutionary body. In another embodiment, the method includes positioning the transmitting phased array device and the receiving phased array device on a periphery of a turbine rotor, transmitting a phased array wave into the turbine rotor, the phased array wave not reflecting off of a reflecting feature, adjusting the positioning of the transmitting phased array devices on the periphery of the turbine rotor, and transmitting the phased array wave into the turbine rotor, the phased array wave reflecting off of a reflecting feature. The reflected phased array wave is received by the receiving phased array device.

Abstract: An array of ultrasonic transducers in a conical formation emits pulses of ultrasonic simultaneously so that an anomaly of any orientation in a test object can be detected efficiently.

Abstract: An inspection fixture is provided that includes a fixture, a lens, an ultrasonic phase array, a mirror and a liquid supply connector. The fixture body includes an inner chamber and an opening to the inner chamber. The lens defines a portion of the inner chamber. The ultrasonic phase array generates ultrasonic signals and is positioned to send the ultrasonic signals through the lens. The mirror is received within the inner chamber and is positioned at 45° in relation to the lens to reflect the ultrasonic signals from the lens, out the opening, to an inspection area of a body to be inspected and to reflect returned ultrasonic signals from the inspection area to the lens. The liquid supply connector is in fluid communication with the inner chamber.

Abstract: A method and apparatus for non-destructively inspecting a composite structure with an ultrasonic system including an ultrasonic probe includes positioning the composite structure in a tank-less environment, and scanning the composite structure with the ultrasonic system to measure ultrasonic sound waves reflected by the composite structure to the single ultrasonic probe. A physical characteristic of the composite structure is determined based at least in part on the measured ultrasonic sound waves.

Abstract: A method of establishing position dependent focal laws and dynamically accessing these focal laws during inspection is disclosed comprising the steps of partitioning a CAD model into distinct geometric regions prior to inspection, generating a dedicated set of focal laws for each of the geometric regions, and associating each position of the scanner with one of the geometric regions. A method of compressing an A-Scan using a windowing technique is also disclosed. Additionally, methods for computing and displaying volumetric slices in real-time are disclosed. Finally, a method of firing multiple probes at different firing frequencies is disclosed, as well as a multi-probe inspection system that enables parallel firing.

Abstract: An embodiment is a method and apparatus for coherent ultrasonic imaging. A receiver array has a plurality of receiver elements on a substrate to detect in-phase and quadrature components of a received signal corresponding to a transmit signal. Each of the receiver elements includes a receiver transducer and a thin-film transistor (TFT) receiver circuit. The TFT receiver circuit includes a quadrature detector having a mixer to mix a received signal with a reference signal in a composite bias signal that is distributed across the plurality of receiver elements. A transmitter is acoustically coupled to the plurality of receiver elements to generate the transmit signal through an imaging medium.

Abstract: An ultrasonic sensor assembly for a test object includes a sensor array having a plurality of sensor elements. The sensor elements detect a characteristic of the test object. The sensor elements are arranged in a matrix formation. Each of the sensor elements includes a transmitter for transmitting a signal and a receiver for receiving the transmitted signal. The sensor array has a curvature that substantially matches a curvature of the test object. A method of detecting characteristics of the test object is also provided.

Abstract: The embodiments disclosed herein relate to various systems and methods for determining the residual stress in polycrystalline materials.

Abstract: An ultrasonic measurement method and an ultrasonic measurement apparatus are capable of performing an inspection for a short time with a high SN ratio and a small variation An ultrasonic measurement method and an ultrasonic measurement apparatus are capable of performing an inspection for a short time with a high SN ratio and a small variation in sensitivity in a process for detecting a defect in all directions at 360 degrees using a matrix array sensor without performing mechanical scanning in all directions, while reducing noise that is caused by a bottom surface echo. An element selecting circuit selects a group of a plurality of ultrasonic transducer elements for transmission from among ultrasonic transducer elements that constitute a two-dimensional array sensor so that the ultrasonic transducer elements for selected for transmission are arranged in line symmetry with respect to a first line symmetric axis to set the group selected for transmission.

Abstract: The disclosed embodiments include a method, system, and device for conducting ultrasound interrogation of a medium. The novel method includes transmitting a non-beamformed or beamformed ultrasound wave into the medium, receiving more than one echoed ultrasound wave from the medium, and converting the received echoed ultrasound wave into digital data. The novel method may further transmit the digital data. In some embodiments, the transmitting may be wireless. The novel device may include transducer elements, an analog-to-digital converter in communication with the transducer elements, and a transmitter in communication with the analog-to-digital converter. The transducers may operate to convert a first electrical energy into an ultrasound wave. The first electrical energy may or may not be beamformed. The transducers also may convert an echoed ultrasound wave into a second electrical energy.

Abstract: Disclosed are systems, methods and articles, including an inspection system that includes at least one generator to apply energy to an object at an application point to cause waves to travel, at least partly, through the object. The system further includes at least one detector configured to detect at least a portion of the waves traveling through the object, and a statistical analyzer to perform a statistical analysis based on an output produced by the at least one detector in response to the detected portion of the waves, the statistical analysis being used to determine whether at least one defect is present in the object.

Abstract: A method for ultrasonic guided wave defect detection in a plate-like structure is disclosed. The method includes driving a plurality of transducers to cause guided waves to be transmitted in the plate in a predetermined direction or focused at a predetermined focal point, receiving at least one reflected guided wave signal, and processing the at least one reflected guided wave signal to identify a location of at least one possible defect in the plate-like structure. Defect detection data including the location of the at least one possible defect in the plate-like structure is stored in a machine readable storage medium.

Abstract: An apparatus for inspecting a tubular workpiece may include a probe assembly and a rotation mechanism. The probe assembly may include a transducer array positionable adjacent to an inner surface of the tubular workpiece. The probe assembly may generate transmitted sound waves and may receive reflected sound waves. The rotation mechanism may rotate the probe assembly relative to the tubular workpiece in a manner such that the transducer array passes over the inner surface in a circumferential direction during transmission of the transmitted sound waves.

Abstract: Equipment of the invention provides ultrasonic flaw detection equipment using a volume focusing flaw detection method, the ultrasonic flaw detection equipment described below. That is, this equipment performs internal flaw detection of a material being tested, the material having a virtually circular cross-sectional shape, and transducers 1 . . . 1 are arranged in an arc along a circle exhibited by the material being tested. Array probes 10 . . . 10 are disposed so as to surround the material being tested. An exciting unit enables flaw detection of the material being tested to be performed by vertical and oblique flaw detection methods.

Abstract: Equipment of the invention uses a volume focusing flaw detection method. In a sectional view of a material m being tested, a plurality of transducers 1 . . . 1 of one of array probes 10 are arranged along one side of a rectangular shape of the material being tested, and a plurality of transducers 1 . . . 1 of the other of the array probes 10 are arranged along one of sides adjacent to the one side.