Abstract: PURPOSE: To provide the biosolution sensor enabling a high accuracy and a small size with an SH-SAW device.

Abstract: A method for detecting an obstruction in a flow duct is provided. The method includes the steps of directing gas through at least one port of the flow duct, measuring a flow noise level of the gas directed through the at least one port, and comparing the noise level with a predetermined noise level. In the event that the flow noise level exceeds the predetermined noise level by at least a threshold amount, then the method includes the step of indicating the presence of an obstruction in the at least one port.

Abstract: The present invention provides a system and method for measuring the surface properties of polishing pads using noncontact ultrasonic reflectance. An ultrasonic probe is located over the polishing surface and configured to both transmit an ultrasonic signal to the polishing surface and receive a modified ultrasonic signal from the polishing surface without contacting the polishing surface. A subsystem coupled to the ultrasonic probe is configured to determine a surface property of the polishing pad from the modified signal.

Abstract: A process for measuring the bond of a coating on a substrate. Ultrasound echoes through the substrate of a test piece are collected and their amplitudes are measured, their decay being a function of the bond of a coating deposited on the opposite face of the substrate. Preliminary tests on calibration test pieces give a correlation function so that it is unnecessary to carry out expensive and uncertain mechanical tests on the test pieces.

Abstract: Methods for obtaining biometric identification data for an individual using a sensor and a processor coupled to the sensor are presented. In an embodiment, the present invention involves placing a portion of a biological object such as a finger, thumb, palm or foot of the individual proximate to piezo ceramic elements of the sensor and generating an output signal with the sensor that is representative of at least one feature of the biological object. The output signal is processed using the processor to produce biological data useful for identifying the individual. In an embodiment of the present invention, the sensor includes at least fifty thousand piezo ceramic elements arranged in an array. These piezo ceramic elements are spaced on a pitch equal to or less than approximately two hundred microns. A multiplexer couples the output of the sensor to the processor.

Abstract: A method to determine a physical quantity within a measuring space by means of acoustic transit time measurement uses an acoustic transducer as a transmitter and an acoustic transducer as a receiver. The two functions can also be combined in a single transducer. The acoustic transit time measurement involves a time-dependent comparison between the shape of an acoustic transmitted signal selected at least partly on the basis of the type of signal processing to be used and at least two points in an acoustic received signal and/or a signal derived from that received signal again selected at least partly on the basis of the type of processing to be used. An apparatus for this method could be equipped with an acoustic signal-generating transducer, an acoustic signal detection transducer, a signal processing device which selects measuring points from the signal, and detection algorithm adapted to the shape of the signal.

Abstract: An improved heat shield provides thermal insulation and reduced noise transmission of vehicular engine components, including exhaust manifolds. The structure has three layers; an outer structural metal layer, a center insulation layer to isolate heat and dampen noise, and an inner metal layer directly adjacent the shielded component for reflecting heat back to the shielded component. The heat shield is attached by bolts to the shielded component. In the described embodiment, the volume of the insulation layer is expanded by approximately 15 to 20 percent over conventional shields to produce a softer, thicker material having a lower density but unchanged mass. The invention provides a technique to achieve desired thickness and density in insulation layers via modal finite element analysis. The relatively thicker heat shield more effectively absorbs vibration and attenuates noise without increase in mass. In the described embodiment, the layer contains cellulose, diatomaceous earth, talc, and fiberglass.

Abstract: Ultrasonic waves are produced at the surface of a thin metal sheet (27) welded to a substrate (28): it was noted that the speed of propagation of the surface waves could then be correlated to the resilience of the welded assembly to enable non-destructive monitoring.

Abstract: A sensor for detecting stress waves for use in a stress wave analysis system. The stress waves are preferably detected in a narrow frequency range of 35-40 KHz. At this range, stress waves from friction and impact sources typically propagate through machine structures at detectable amplitudes. In order to maximize the signal to noise ratio of stress waves, relative to background noise and vibration, the sensor of the present invention is designed and calibrated with a frequency response and damping features that are specifically tailored for stress wave analysis. The sensor is a multi-functional sensor that can measure a number of logically related parameters for indicting the mechanical condition of a machine. It is often desirable to measure both friction and one or more other parameters appropriate for indication of a machine's health, where all of the measuring capability is contained in one sensor.

Abstract: The contents of a container 1 are non-intrusively monitored by probing the container with an ultrasonic signal, and measuring changes in the ultrasound signature of the received signal after the signal has passed through the contents of the container.

Abstract: In the prevent invention a controllable acoustic source (14) in connection with the process fluid (10) emits a signal (18) into the fluid (10), consisting of a suspension of particles (12), being volumes of gas, liquid or solid phase. The controllable acoustic signal (18) is allowed to interact with the particles (12), and the acoustic (pressure) signals (22) resulting from such an interaction is measured preferably via a sensor (24). A spectrum is measured. The spectrum is used to predict properties, content and/or size of the particles (12) and/or used to control a process in which the process fluid (10) participates. The prediction is performed in the view of the control of the acoustic source (14). The used acoustic signal has preferably a frequency below 20 kHz.

Abstract: While a transmitting transducer (2a) for transmitting an ultrasonic wave and a receiving transducer (2b) for receiving an ultrasonic wave are moved within a predetermined circular region (7) on a surface of a material being measured, ultrasonic waves are transmitted and received 10,000 times. Then, arithmetic averaging is performed every time an ultrasonic wave is received, on the ultrasonic wave and ultrasonic waves that have been received until then. For example, the aforementioned predetermined frequency is given by ((n±(½))×(106×v/&Dgr;L))(Hz), where &Dgr;L is a variation in distance between the transmitting transducer and the receiving transducer, v is a transmission velocity of an ultrasonic wave transmitting in a material being detected, and n is a natural number.

Abstract: A process for determining the polymer concentration in a spinning dope solution involves measuring the propagation velocity of ultrasonic sound in the solution. The process prevents fluctuations in the polymer concentration as much as possible, and is therefore highly suitable for application in the production of fibers with consistent properties. An ultrasonic device used in the process is easier to clean, install, and calibrate than other presently commercially available devices.

Abstract: A method and system for processing laser vibrometry data are embodied in a processor configured to employ a statistical signal processing technique (e.g., a Bayesian processing technique) to process one or more mathematical models, laser vibrometry data for a system under observation, and prior information to generate estimates of parameters for the one or more mathematical models.

Abstract: An acoustoelectronic method and apparatus for generating real-time three-dimensional images of an object and characterizing such object are provided. The object is insonified with an incident acoustic signal derived from an electrical signal. Acoustic signals scattered from the object are collected by an acoustic receiver, which generates analog electrical signals that are subsequently converted to digital electronic signals. The digital electronic signals are used in both direct-imaging and holographic methods to produce a three-dimensional representation of the object from which images and characterizations can be generated.

Abstract: The temperature distribution in water is measured by two thermocouples to obtain a temperature compensating parameter. Under measurement conditions where the temperature distribution in water varies, a measured V(z) curve is used to monitor a change in the wave number of a longitudinal wave in an ultrasonic wave propagation region in water to thereby detect variations in the water temperature and the longitudinal wave velocity with high accuracy.

Abstract: A system and method for testing a physical attribute of a manufactured object that includes a laser generator and pulse generator that generate a plurality of Dirac-like pulses. The pulses, directed at an object, cause a sonic signal to be initiated indicative of the physical attribute of the manufactured object, and are detected. The system also controls the width of the Dirac-like pulses and time separation between pulses. A display may also be used to present the detected signal or physical attribute. The Dirac-like pulses are structured to produce a particular output in the manufactured object. The Dirac-like pulses may be altered dynamically in the presence of deviations from the expected output. One embodiment of the Dirac-like pulses is a series of pulses with pulse widths less than 20% a time separation between successive pulses.

Abstract: In a method of detecting discontinuities on elongated workpieces, in particular tubes and bars, using ultrasonic testing system, a test object is positioned in relationship to a test head of the testing system, with the test object and the test head being moveable to one another. Signals from the test head are transmitted to an evaluation unit, where they are digitized and evaluated. The digitized signals of a test shot of a length position X are compared with digitized signals of a test shot of a length position X+&Dgr;X, wherein &Dgr;X is a multiple of a shot distance, and the difference is evaluated.

Abstract: In a method for contactless online measuring of the wall thickness of hot-rolled pipes in the hot state for determining undesirable inner wall structures, at least one measuring head, operating according to the laser ultrasound method, scans a segment of a wall of a pipe to be measured in a circumferential direction during or directly after a rolling process. The course of the wall of a cross-section of the pipe is then reconstructed with a computer. The measuring head is a compact laser ultrasound measuring head adjustable relative to the pipe dimension to be measured. It has an excitation laser and an illumination laser and optical elements for collecting a carrier light containing the ultrasound signal and reflected at a surface of the pipe. The excitation and illumination lasers and the optical elements are arranged in a common housing of the measuring head. A pivot device is provided to pivot the laser ultrasound measuring head across a segment of the pipe in the circumferential direction.

Abstract: The invention concerns an apparatus for inspecting and calculating the residual strength of an aramid fiber cable driving an elevator to determine when such cable is in need of replacement. The apparatus includes a transmitter for introducing an acoustic wave that will travel along the aramid fiber cable and a receiver for receiving the acoustic wave after its has traversed a designated section of the cable. The transmitter and receiver provide signals indicating the times the wave was sent by the transmitter and thereafter received by the receiver. From these signals, a program in the system calculates the wave velocity and the modulus, and the residual strength of the aramid cable.

Abstract: A method is described for examining a solidifying and/or hardening material such as cement, concrete or the like, using ultrasound waves emitted by an ultrasound transmitter, which penetrate the solidifying and/or hardening material, are continuously measured and analyzed. During solidification and/or hardening of the material, the signal shapes of the ultrasound waves penetrating the material, are recorded. The change with time of the compression wave velocity and/or the relative energy of the ultrasound waves and/or the frequency spectra of the ultrasound waves is extracted from the ultrasound wave shapes during the entire course of solidification and/or hardening of the material. This change with time of the compression wave velocity and/or the relative energy of the ultrasound waves and/or the frequency spectra of the ultrasound waves is approximated through a compensating function, preferably the Boltzmann function.

Abstract: Plate waves are used to determine the presence of defects within a porous medium, such as a membrane. An acoustic wave can be propagated through a porous medium to create a plate wave within the medium. The plate wave creates fast compression waves and slow compression waves within the medium that relate to the material and structural properties of the medium. The fast compression wave provides information about the total porosity of a medium. While the slow compression wave provides information about the presence of defects in the medium or the types of materials that form the medium.

Abstract: The claimed method of in-tube ultrasonic flaw detection of pipelines is effected, in accordance with one embodiment, by placing inside a pipeline an inspection pig or flaw detector having ultrasonic transducers, devices for measurements, processing and storage of the measured data. During the pig travel, the transducers emit probing ultrasonic pulses and receive the reflected pulses corresponding to said probing pulse thus deriving data on the time intervals corresponding to the transit time of said pulses, the measured data being converted and stored.

Abstract: An improvement in an on-line measurement system for product formed in a continuous manner includes a device for receiving a first waveform signal indicative of a presence of a first characteristic of the product and a second waveform signal indicative of a presence of a second characteristic of the product. A computer based device having phase shifting software is provided for shifting phase of each of the first waveform signal and the second waveform signal a predetermined amount to produce a respective first transformed waveform signal and a second transformed waveform signal.

Abstract: Ultrasonic sensors can be integrated and used to monitor composites throughout their production and during their useful lifetime. In an integrated program, ultrasonic sensors, in the illustrated embodiment contact sensors, can be used for quality control on raw rubber used for making a composite and for monitoring the cure of the rubber as it is transformed into a useful product, and non-contact sensors can be used to evaluate the product when it is completed, and to monitor its aging and wear during use. Such sensors can also be used in research to evaluate potential raw materials, and to compare cured candidate materials for properties useful in a completed product.

Abstract: An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.

Abstract: A system for measuring sound velocity in material comprises a piezoelectric substrate, first- and second comb-shaped electrodes, and a counter electrode in contact with a surface-part of a material. When input electric signals Ei having carrier frequencies fi, respectively, are applied between the first comb-shaped electrode and the counter electrode in turn, longitudinal waves are radiated into the material. The longitudinal waves are reflected at the opposite surface-part of the material, and then, detected between the second comb-shaped electrode and the counter electrode as delayed electric signals Di, respectively. The input electric signals Ei and the delayed electric signals Di interfere respectively, so that respective interference signals Ri occur. A sound velocity V in the material is estimated from the interference signals Ri.

Abstract: Electromagnetic acoustic resonance method by using EMAT is used for determining hydrogen concentration of radioactive metallic object. In one preferred embodiment, resonance frequencies fr, fr are measured with the EMAT, where where fr is a resonance frequency when a direction of an amplitude of a transverse ultrasonic wave generated by the EMAT is the same as the rolling direction of the metallic object of rolled material, and ft is a resonance frequency when a direction of the amplitude of the transverse ultrasonic wave is perpendicular to the rolling direction. A value R is calculated by using: R=(fr−ft)/{(fr+ft)/2}. The hydrogen concentration of the metallic object is calculated on the basis of the experimentally determined relation between the value R and hydrogen concentration.

Abstract: A vibration displacement sensing system comprises a piezoelectric substrate, first- and second comb-shaped electrodes, a counter electrode, and a signal analyzer. When input electric signals are applied between the first comb-shaped electrode and the counter electrode, longitudinal waves are radiated into a medium, and reflected at a material in the medium. If the material vibrates in response to times Ti, reflected longitudinal waves are detected between the second comb-shaped electrode and the counter electrode as delayed electric signals Di in accordance with distances Zi between the counter electrode and the material. In this time, the distances Zi correspond with the times Ti, respectively. Electrical coupled-signals from the input electric signals and the delayed electric signals Di interfere respectively, so that respective interference signals Ri occur. A vibration displacement caused by the material is estimated from the interference signals Ri.

Abstract: A method for the determining ultrasonic sound propagation speed and wall thickness of a tubular object. Time-domain and frequency-domain analyses are used, where the latter can determine acoustic dispersion if the specimen is made up of a dispersive material. Time of flight data is sensed from a series of transmitted ultrasonic waves, some of which are reflected and some of which are transmitted. The time of flight data can be used to calculate speed of sound in the tube, as well as wall thickness. Inherent in the time of flight data is the speed of the ultrasonic wave; accordingly, correction for temperature variations in the tube is not required. The calculations based on measured speed of sound quantities produces more accurate results than in calculations where the speed of sound in the specimen is assumed.

Abstract: A method and apparatus for measuring the relative density of a gas. The apparatus includes a chamber to which a gas in question, for example natural gas, is supplied through an inlet and leaves through an outlet. The speed of sound SoS at ambient temperature is measured using any suitable method such as electronic control and a calculating device and an ultra-sound emitter and an ultra-sound receiver. The ambient temperature Ta is observed by a temperature sensor, and a thermal conductivity sensor measures the thermal conductivity of the gas at two different temperatures above the ambient temperature. One value ThCH of the thermal conductivity is measured at 70° C. above ambient and the other value ThCL of the thermal conductivity is measured at 50° C. above ambient. The control calculates the relative density RD of the gas according to the formula RD=g·ThCH+h·ThCL+i·SoS+j·Ta+k·.Ta2+l where (g, h, i, j, k and l) are constants.

Abstract: A method for quality control monitoring of laser shock peening a surface of a production workpiece during which laser beam pulses form a plurality of corresponding plasmas. An acoustic signal of each laser beam pulse during a period of time during a duration of each corresponding one of the plasmas is monitored and an acoustic energy parameter value for each of the acoustic signals for each of the corresponding laser pulses is calculated. A statistical function value of the workpiece based on the acoustic energy parameter values is calculated and compared to a pass or fail criteria for accepting or rejecting the workpiece. The criteria may be based on a pre-determined correlation of test piece statistical function data such as high cycle fatigue failure data of test pieces. The statistical function value may be an average of the acoustic energy parameter values of the laser beam pulses.

Abstract: These objects are achieved by a method of acoustically inspecting a one-piece bladed wheel in which the wheel is driven in rotation; each blade of the wheel is subjected to mechanical excitation; its acoustic response is picked up and a corresponding electrical signal is generated; its frequency response is determined by computing a FFT; the electrical signal and the associated frequency response are stored; the characteristic frequencies of each blade of the wheel are identified; and a wheel is rejected or accepted depending on whether or not the frequency distribution obtained in this way matches a predetermined set of forbidden frequency distributions. Advantageously, an additional step is provided in which the defects of a blade are determined by comparing its frequency response with predetermined frequency responses that are characteristic of various types of defect.

Abstract: The invention relates to a method for verifying thickness modulations, in particular watermarks, in or on sheet material. To diminish the influence of disturbances from the surroundings and reduce the adjustment effort during production and maintenance of corresponding measuring systems, the sheet material is subjected to sound, in particular ultrasound, the sound transmitted through the sheet material and/or reflected on the sheet material is measured at a plurality of places on the sheet material, at least one value characteristic of the transmitted and/or reflected sound is generated for each of the places, and the thickness modulations are verified by comparing the values with predetermined reference values.

Abstract: An ultrasound imaging method forms an image of an object using signals reflected from the object after transmitting an ultrasound pulse to the object. In the method, at a first step, a predetermined first spread spectrum signal is converted to the ultrasound signal at one or more transducers and the ultrasound signal is transmitted to the object. At a second step, pulse compression is performed on a reflected signal of the ultrasound signal reflected from the object to form a pulse compressed signal. And the pulse compressed signal is processed to produce a receive-focused signal and the image of the object from the receive-focused signal is generated.

Abstract: The Roll Defect Management Process (RDMP) is a system which is designed to manage, track and evaluate all mill rolls found in use in the hot and cold production of flat rolled metal strip. The RDMP is capable of detection, distinction and differentiation of various defects found in the mill roll using a nondestructive inspection system for generating variable amplitude output voltage signals corresponding to changes in physical properties found in a mill roll and defines corrective action for each roll type, mill, stand and position. The disposition and corrective actions of the RDMP are automated and dependent on the determination of various thresholds identified by roll, mill and stand.

Abstract: A method and apparatus of measuring a predetermined parameter having a known relation to the transit time of movement of an energy wave through a medium, by transmitting from a first location in the medium a cyclically-repeating energy wave; receiving the cyclically-repeating energy wave at a second location in the medium; detecting a predetermined fiducial point in the cyclically-repeating energy wave received at the second location; continuously changing the frequency of transmission of the cyclically-repeating energy wave from the first location to the second location in accordance with the detected fiducial point of each received cyclically-repeating energy wave received at the second location such that the number of waves received at the second location from the first location is a whole integer; and utilizing the change in frequency to produce a measurement of the predetermined parameter.

Abstract: A method and system for determining meat quality in cattle is provided. In preferred embodiments the method comprises obtaining an ultrasound measurement of a cattle specimen between the 12th rib and 13th rib at weaning age. The ultrasound measurement is utilized to extrapolate a harvest quality parameter. Based on the harvest quality parameter, and preferably a yield grade, the specimen is categorized. Particularly preferred harvest quality parameters are ribeye area, fat thickness, intramuscular fat and ribeye shape. Methods for determining tenderness, stress and intramuscular fat are described and claimed.

Abstract: A crack detection method and system capable of detecting cracks on a scale of about 5 &mgr;m or greater, useful for detecting cracks in sol-gel tubes. An electromagnetic radiation signal is transmitted from a sensor to a body in which cracking may occur. The signal is reflected back to and received by the sensor. An output voltage from the sensor is measured which is proportional to a signal characteristic change between the transmitted and received signals. Signal characteristics such as frequency, phase, and amplitude may be monitored. The signal characteristic change may result from one or more mechanisms selected from the group consisting of microscopic motion of the body, media transition and fluid movement.

Abstract: An inclination angle measurement apparatus includes a first ultrasonic sensor (3) for sending an ultrasonic wave toward a reflective object (2), second and third ultrasonic sensors (4 and 5) each for receiving an ultrasonic wave reflected from the reflective object (2), and a calculation control circuit (14) for calculating an angle of inclination of a moving object with respect to the reflective object (2) based on a phase difference between ultrasonic waves received by the second and third ultrasonic sensors (4 and 5). Thus the inclination angle measurement apparatus can accurately measure the angle of inclination of the moving object with respect to the reflective object (2).

Abstract: An invention to measure of objects of non-homogeneous ultrasonic impedance in the testing path is provided to detect the present of flaws in any part of the object. The invention utilized a reference signal to compare against the actual signal derived from ultrasonic testing of the object. Reference signals are determined based upon the known or calculated properties of the object's layers or previously obtained signals measured from the object.

Abstract: A damage evaluation method and apparatus of a metal material which is capable of determining whether a flaw in the metal sample is originated by the creep damage or in the manufacturing process, and also capable of estimating a remaining life of the metal component. The damage evaluation method of a metal material by the present invention is a method for evaluating a flaw in the metal sample comprising the steps of mounting onto a metal surface including an internal flaw and on both sides of the flaw a transmitting probe for transmitting an ultrasonic waves and a receiving probe for receiving the ultrasonic waves, transmitting the ultrasonic waves towards the internal flaw and receiving the diffracted wave from the flaw for determining whether or not a flaw is present in the metal, based on the analysis of the distribution of the diffracted waves and an analysis of the sample as to whether voids (creep voids) are present and, if present, the distribution of the voids.

Abstract: The channeled wavefield transformer enables multi-dimensional wavefield signal processing which leads to significant expansion of the engineering field of electronic signal processing. The term “wavefield” is used to indicate one or more waves that operate in at least two dimensions of space where spatial form of a wave can be represented by a wavefront that is a surface of points of equal phase. This transformer produces an output wavefield in a clear medium in response to an arbitrary input wavefield. This is carried out using multiple channels that connect input sensing devices to respective output transmitting devices. The input devices are arranged along an input surface and the output transmitting devices are arranged along an output surface. An output wavefield emerges from the output surface to propagate in an output wavefield space.

Abstract: A method of predicting warp of lumber that might be sawn from any given log is disclosed. The method involves measurement of stress wave velocity in the tree stem. A scan is then made to define the exterior geometric configuration of the log. In particular, measurements relating to lack of longitudinal axis linearity (sweep) or irregularity of cross sections of the log are important. Stress wave values and selected geometric parameters are entered into a multivariate regression equation to predict warp propensity of lumber that might be sawn from the log. The equations are originally derived by examination of a representative population of logs of the particular species and locale and measurement of warp in lumber sawn from the logs. Logs determined to produce warp prone lumber can be isolated and used to produce other products such as timbers or plywood where warp is not as critical.

Abstract: A method for determining structural inhomogeneities in sheet material including exposing sheet material to ultrasonic waves, measuring ultrasonic waves transmitted through the sheet material and ultrasonic waves reflected from the sheet material at a plurality of predetermined portions located linearly along at least one track disposed on the sheet material and producing at least one value characteristic based on at least the transmitted or reflected ultrasonic waves from each of the predetermined portions on the at least one track. The method further includes forming a first mean based on the at least one value characteristic and a second mean based on the first mean to determine the structural inhomogeneities in the sheet material representative of the at least one track.

Abstract: A sealant stream anomaly detecting assembly for detecting anomalies such as gas bubbles in a high-pressure sealant stream. The assembly includes an ultrasonic transducer supported on a manifold defining a sensing chamber of a fluid channel. The transducer converts electrical voltage pulses into ultrasonic acoustic pulses and propagates the acoustic pulses through the manifold and into the sensing chamber. The transducer also receives resulting echo pulses from a back wall of the sensing chamber and converts the echo pulses into electrical output impulses. A control module including drive electronics is connected to the transducer. The module detects diminished and lost echo pulses by comparing the output impulse strength values for a given fluid passing through the sensing chamber to a known output impulse strength value for that same type of fluid having no anomalies.

Abstract: A device for detecting or analyzing machinery damage is used preferably in the determination of defects in roller bearings. Pulse-like machinery or bearing noise acquired by a sensor is converted into special time signals. These time signals correspond to events which are basically periodic in occurrence. The time signals are sent to one, preferably several, classification units depending on the time differences. Before classification, combination of adjacent time signals or events is performed using their pulse heights. The combining is multiplicative or obeys some other bivalent relation. Classification forms a frequency distribution with an abscissa which is divided into time units. Specific characteristics of the frequency distribution provide information on incipient or manifest machinery damage.

Abstract: While a transmitting transducer (2a) for transmitting an ultrasonic wave and a receiving transducer (2b) for receiving an ultrasonic wave are moved within a predetermined circular region (7) on a surface of a material being measured, ultrasonic waves are transmitted and received 10,000 times. Then, arithmetic averaging is performed every time an ultrasonic wave is received, on the ultrasonic wave and ultrasonic waves that have been received until then. For example, the aforementioned predetermined frequency is given by ((n±(½))×(106×v/&Dgr;L))(Hz), where &Dgr;L is a variation in distance between the transmitting transducer and the receiving transducer, v is a transmission velocity of an ultrasonic wave transmitting in a material being detected, and n is a natural number.

Abstract: Ultrasonic sensors can be integrated and used to monitor composites throughout their production and during their useful lifetime. In an integrated program, ultrasonic sensors, in the illustrated embodiment contact sensors, can be used for quality control on raw rubber used for making a composite and for monitoring the cure of the rubber as it is transformed into a useful product, and non-contact sensors can be used to evaluate the product when it is completed, and to monitor its aging and wear during use. Such sensors can also be used in research to evaluate potential raw materials, and to compare cured candidate materials for properties useful in a completed product.

Abstract: A method for inspecting concrete structures includes the steps of exciting the structure to be inspected with a mechanical device such as a chain, sensing resulting vibrations with an acoustical sensor such as a microphone that is not physically coupled to the structure, processing the received signals to exclude signals with frequencies outside of response frequencies of interest corresponding to defects desired to be detected, and examining the received signals. In preferred embodiments, the mean square of the processed signals are compared to a threshold. Areas for which the total energy across the frequency bands of interest exceeds the threshold correspond to defects such as delaminations. The received signals are collected from various locations on the structure. In preferred embodiments, the location of the received signals is also maintained.