Abstract: An ultrasonic flaw detection apparatus is equipped with a probe which is driven by a transmission signal and which transmits an ultrasonic pulse at an angle with respect to a surface of a test object. The probe receives an ultrasonic pulse, which has been reflected by a defect in the test object, as an echo. The apparatus further includes a scanner for scanning the probe over a predetermined scanning zone on the test object and for outputting a spatial position of the probe. The apparatus is further equipped with a transmitter-receiver which has a transmitter for generating a transmission signal and outputting the transmission signal to the probe, a position detector for receiving a spatial position of the probe from the scanner, and a signal processor for detecting the defect according to the stored spatial position of the probe and the stored echo, taking the spread of an ultrasonic beam attributable to diffraction into account.

Abstract: The invention relates to an electrical surface treatment device which is provided with an acoustic surface type detector with which a type of a surface to be treated can be detected during operation. According to the invention, the surface type detector delivers an output signal (u.sub.FT) during operation which is characteristic of the type of surface to be treated and which is determined by a value of a physical quantity of air vibrations reflected by the surface to be treated, which value is measured by a vibration detector of the surface type detector. In a special embodiment, the physical quantity is an amplitude, and the surface type detector is a vibration generator for generating air vibrations having a predetermined amplitude. The generated air vibrations preferably have a frequency of at least 15,000 Hz which varies within a predetermined range.

Abstract: A load-indicating device including a load-bearing member adapted to deform when stressed. Ultrasonic waves are directed into one end of the load-bearing member and ultrasonic echoes are received at the same end by ultrasonic wave transmitting and receiving equipment. In one embodiment, ultrasonic waves are transmitted and received using an ultrasonic transducer disposed on either the head or the opposite end of the load-bearing member. The head, the end, the shank or a combination thereof are contoured to reduce the influence of geometric variations and asymmetrical stress in the load-bearing member on the ultrasonic measurement. A method is also provided, which encompasses a model, by which preferred geometries of the contoured surfaces of the load-bearing member can be designed.

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

Abstract: Ultrasonic sensors and associated methods for on-line monitoring of material properties for die casting, molding and extrusion processes at elevated temperatures are disclosed. The sensors include the use of ultrasonic waveguides embedded in the processing machines and piezoelectric ultrasonic transducers. The sensors are operated in the reflection geometry in which one side access of the processing machines is required. The monitoring parameters are the flow front, gap development and temperature of the materials being processed and filled in the cavities of the die in casting processes and the mold in injection molding, and the temperature and viscosity of the molten polymers in the polymer extrusion machines.

Abstract: A contaminant detection system includes a transmitter for transmitting a guided wave through the skin at particular resonances, wherein each resonance point utilized will have propagation characteristics sensitive to a condition of interest. A contaminant may then be classified by transmitting several resonances and then carrying out appropriate feature extraction and pattern recognition techniques utilizing a host processor.

Abstract: An ultrasonic material constant measuring system comprising a reference unit, an examination unit, at least a case equipped in at least the examination unit, and a signal processing unit. The reference unit consists of at least an input ultrasonic transducer T.sub.o and at least an output ultrasonic transducer R.sub.o. The examination unit consists of at least an input ultrasonic transducer T.sub.s and at least an output ultrasonic transducer R.sub.s. The case is placed between the ultrasonic transducers T.sub.s and R.sub.s. The signal processing unit is connected with output terminals of the ultrasonic transducers R.sub.o and R.sub.s. When electric signals are applied to the ultrasonic transducers T.sub.o and T.sub.s, ultrasounds are emitted in air from the ultrasonic transducers T.sub.o and T.sub.s, respectively, and then received by the ultrasonic transducers R.sub.o and R.sub.s, respectively. If at least a sheet of paper is placed in case 1, the ultrasound emitted from ultrasonic transducer T.sub.

Abstract: Measuring the limpness of a note is necessary to separate a worn note out of circulation. Several methods are disclosed which can be used either alone or in combination to test for limpness. One method measures the note's ability to reflect light or transmit the light. Another method measures the response of the note to an acoustic wave. Another method measures the note's deflection to a pressure or force. Yet another method measures the dielectric value of the note when placed between the plates of a capacitor. A final method involves measuring the thermal conductivity of the note. In each case, a limp note will produce distinguishable results from a stiff note.

Abstract: An apparatus and method are disclosed wherein a linear array of electromagnetic radiation emitting devices are arranged in association with a moving workpiece. Electromagnetic radiation emitted by the array is received by two or more receivers. Several non-contact measurements may be obtained on a workpiece using the present apparatus and methods.

Abstract: The present invention includes a fully programmable plurality of multi-channel receivers, each receiver having a digital multi-channel receive processor and a local processor control. Each receive processor includes a first decimator, time delay memory, second decimator, and complex multiplier. The receive beamformer is a computationally efficient system which is programmable to allow processing mode trade-offs among receive frequency, receive spatial range resolution, and number of simultaneous beams received. Each local control receives focusing data from a central control computer and provides final calculation of per-channel dynamic focus delay, phase, apodization, and calibration values for each receiver signal sample. Further, this invention includes a baseband multi-beam processor which has a phase aligner and a baseband filter for making post-beamformation coherent phase adjustments and signal shaping, respectively.

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: An ultrasonic inspection technique using a specially designed electromagnetic acoustic transducer (EMAT) launches and receives longitudinal ultrasonic waves into a thin metal wall or thin metal foil seal of a container, causing it to vibrate and launch ultrasonic compressional waves into liquid contained therein. The contents of plastic containers having a metal foil seal forming one wall are easily inspected. The EMAT establishes a magnetic field in the surface of the metal parallel to the surface. Radio frequency (RF) eddy currents are also induced by the EMAT in the surface of the metal. A Lorentz force is generated in the metal surface according the vector product of J, the current density, and H, the magnetic field, and the force generated by the interaction of the perpendicular components of the magnetic field H and the eddy currents J is directed normally to the surface of the metal.

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

Abstract: A non-destructive method of identifying a type of compound in a sample using an acoustic microscope, particularly, identifying the type of compound used in an integrated circuit package by comparing attributes of the tested molding compound with known attributes of known compounds to identify the compound being evaluated. The attributes that are compared include voltage, attenuation, peak frequency, average frequency, and the velocity of reflected sound.

Abstract: An apparatus and method are disclosed wherein a linear array of electromagnetic radiation emitting devices are arranged in association with a moving workpiece. Electromagnetic radiation emitted by the array is received by two or more receivers. Several non-contact measurements may be obtained on a workpiece using the present apparatus and methods.

Abstract: A method for rapid, noninvasive identification and monitoring of chemicals in sealed containers or containers where direct access to the chemical is not possible is described. Multiple ultrasonic acoustic properties (up to four) of a fluid are simultaneously determined. The present invention can be used for chemical identification and for determining changes in known chemicals from a variety of sources. It is not possible to identify all known chemicals based on the measured parameters, but known classes of chemicals in suspected containers, such as in chemical munitions, can be characterized. In addition, a large number of industrial chemicals can be identified.

Abstract: A system for ultrasound transmission in materials comprising a reference unit, an examination unit, at least a case equipped in at least the examination unit, and a signal processing unit. The reference unit consists of at least an input ultrasonic transducer T.sub.o and at least an output ultrasonic transducer R.sub.o. The examination unit consists of at least an input ultrasonic transducer T.sub.s and at least an output ultrasonic transducer R.sub.s. The case is placed between the ultrasonic transducers T.sub.s and R.sub.s. The signal processing unit is connected with output terminals of the ultrasonic transducers R.sub.o and R.sub.s. When electric signals are applied to the ultrasonic transducers T.sub.o and T.sub.s, ultrasounds are emitted in air from the ultrasonic transducers T.sub.o and T.sub.s, respectively, and then received by the ultrasonic transducers R.sub.o and R.sub.s, respectively.

Abstract: This invention provides a closed-loop system for in situ testing of formation fluid conditions and for selectively collecting substantially mud filtrate free formation fluid samples at original formation conditions. The system contains an elongated member having a probe that is sealingly placed against the wellbore formation to withdraw formation fluids. A surface controlled pump controls the flow of a fluid from the formation into a flowline placed in the elongated member. A pressure sensor provides downhole hydrostatic pressure and an acoustic density cell provides the speed of sound in the fluid, acoustic impedance of the fluid and acoustic absorption coefficient of the fluid in the flowline. The system determines the density and compressibility of the formation fluid in the flowline from the speed of sound in the fluid and acoustic impedance of the fluid. The formation of the bubbles are identified or detected from the acoustic absorption coefficient of the fluid in the flowline.

Abstract: The apparatus and method for evaluating images for quality assurance parameters of ultrasound image scanners are described. The apparatus includes a digital computer with display output, a video frame grabber or direct image read-out interface from ultrasound scanner, a digital storage, and software. Using a transducer, an ultrasound scanner produces an image, of test objects or phantom, that is temporarily stored in scanner memory. The phantom image is transferred to the memory of the processing computer either by digitizing the video output of the scanner or reading directly by digital means from the scanner. The software enables the user to acquire the image by the above means; associate the images with information on scanner, operator, and expected performance standards and accuracies. As selected by user, the software evaluates scanner performance parameters and produces quantitative results, graphs, and reports for screen display and printer.

Abstract: Ultrasonic waves from a transmit device are transmitted to an object subject to measurement. A surface reflected wave propagated in a contact medium and reflected at the surface of a tube and bottom surface reflected waves passing through an oxidation layer on the tube and reflected at the inner surface of the tube are convened into electric signals. A feature extracting part 5, in consideration of a correlation relationship of energy with respect to the frequency of a received signal, based on the received signal of ultrasonic waves converted to electric signals, extracts a signal feature data determined beforehand which has a strong correlation relationship with the thickness of a measured part. Based on the extracted signal feature data, a thickness conversion part references a relationship storage part which has stored therein beforehand a function that shows a relationship between the signal feature data and the thickness of the oxidation layer, and obtains the thickness of the oxidation layer.

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

Abstract: New physical principles are used to determine the number of inventory goods on a store's display shelves. One principle involves transmitting waves (mechanical, sound or ultrasound) thru an unknown number of goods resting on an insulated plate. Another principle to determine the unknown mass is the inertial response caused by mechanical vibration. By measuring the reflected waves or response time, a computer or processor can determine the steady state condition. For the absorption method, the device receives waves and determines when the phase angle difference (between the transmitter's wave profile and the receivers' average wave profile) is zero. This zero phase angle means a standing wave exists in the insulated plate and its goods. By subtracting the intensities of the waves (transmitter minus receivers' average) the total absorption energy can be determined.

Abstract: A method for nonintrusive monitoring of slow speed machinery incorporates a high sensitivity accelerometer capable of detecting low level mechanical vibrations, and a standard data collector/analyzer for processing the accelerometer output in accordance with a slow speed technology (SST) methodology that is implemented by firmware or software. To prevent the high frequency components from overwhelming the low frequency components of the accelerometer output as a result of dynamic range loss during processing of the accelerometer output by the data collector/analyzer, the SST methodology converts the accelerometer output from the acceleration domain to the velocity domain with an analog integrator that amplifies the low frequency components of the accelerometer output while attenuating the high frequency components. The analog integrator distorts the low frequency vibration components as well as the electrical noise introduced by the accelerometer.

Abstract: A non-destructive method of identifying a type of molding compound in a sample using an acoustic microscope, particularly, identifying the type of molding compound used in an integrated circuit package by comparing attributes of the tested molding compound with known attributes of standard molding compounds to identify the molding compound being evaluated. The attributes that are compared include voltage, attenuation, peak frequency, average frequency, and the velocity of reflected sound.

Abstract: A contaminant detection system includes a transmitter for transmitting a guided wave through the skin at particular resonances, wherein each resonance point utilized will have propagation characteristics sensitive to a condition of interest. A contaminant may then be classified by transmitting several resonances and then carrying out appropriate feature extraction and pattern recognition techniques utilizing a host processor.

Abstract: The present invention comprises an image processing system to process an array of ultrasonic scanning image data. The image processing system is capable of performing local attenuation estimations by the use of the scanned data and displaying the estimated local attenuations in clearly identifiable images whereby the results of the ultrasonic scan can be accurately and easily interpreted. The estimation process comprises the steps of macro segmentation, micro segmentation, classification, and filtering wherein various techniques of average thresholds, classification and homogenization are used to minimize measurement noises and determine the pixels within a homogeneous geometrical element.

Abstract: A method and apparatus for obtaining information relating to the eating quality of meat. The meat under test may include a hot or cold meat carcass, raw or cooked meat or live animal. The method includes the steps of injecting an acoustic signal into the meat, monitoring the effect of the meat on at least one characteristic of the acoustic signal propagated into the meat, and applying the monitored effects to a predetermined algorithm relating eating quality to monitored acoustic effects to indicate the eating quality of the meat under test. The acoustic probe assembly of the apparatus includes a pair of arms adapted for insertion into a meat carcass. The arms carry respective means for coupling acoustic signals into and receiving signals from the carcass. Further, the arms include means for coupling the acoustic signals to the surface of a carcass and monitoring scattering of the acoustic signals to predict the eating quality of meat.

Abstract: An ultrasonic inspection technique using a specially designed electromagnetic acoustic transducer (EMAT) launches and receives longitudinal ultrasonic waves into a thin metal wall or thin metal foil seal of a container, causing it to vibrate and launch ultrasonic compressional waves into liquid contained therein. The contents of plastic containers having a metal foil seal forming one wall are easily inspected. The EMAT establishes a magnetic field in the surface of the metal parallel to the surface. Radio frequency (RF) eddy currents are also induced by the EMAT in the surface of the metal. A Lorentz force is generated in the metal surface according the vector product of J, the current density, and H, the magnetic field, and the force generated by the interaction of the perpendicular components of the magnetic field H and the eddy currents J is directed normally to the surface of the metal.

Abstract: The thickness of a vapor barrier layer embedded in a co-extruded plastic fuel tank is measured using ultrasound. An interference method using ultrasonic tone-bursts employs a frequency progression wherein a frequency producing a minimum in the reflection echo from the barrier layer identifies the thickness of the barrier layer. The method is useful in polyethylene fuel tanks wherein an ultrasonic attenuation which is highly dependent upon frequency limits the resolution of barrier layer thickness.

Abstract: A method for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein. A direct correlation between the octane rating of gasoline and the frequency of corresponding acoustic resonances therein has been experimentally observed. Therefore, the octane rating of a gasoline sample can be directly determined through speed of sound measurements instead of by the cumbersome process of quantifying the knocking quality of the gasoline. Various receptacle geometries and construction materials may be employed. Moreover, it is anticipated that the measurements can be performed on flowing samples in pipes, thereby rendering the present method useful in refineries and distilleries.

Abstract: The present invention is directed to a method of displaying the Poisson's ratio image of a material part. In the present invention longitudinal data is produced using a longitudinal wave transducer and shear wave data is produced using a shear wave transducer. The respective data is then used to calculate the Poisson's ratio for the entire material part. The Poisson's ratio approximations are then used to displayed the image.

Abstract: An ultrasonic edge detector system wherein the lateral position of a moving web or sheet is monitored by projecting an ultrasonic beam from a transmitting transducer toward a receiving transducer and the web edge occludes or shadows more or less of the ultrasonic beam changing the ultrasonic energy received by the receiving transducer. Changes in output of the receiving transducer are detected as a measure of change in edge position. Accuracy in the measurement of the position of the edge is achieved by lengthening the path of acoustic energy from the transmitting transducer to the receiving transducer by positioning an acoustic reflector in said path. Reverberations are reduced by causing the angle of incidence of the ultrasonic beam to be at an angle .alpha. of greater than 0 degrees. A dual receiving transducer system is disclosed compensating for fluctuations in power to the edge detector system.

Abstract: A method is disclosed for identifying the presence or concentration of a target species in a sample by transmitting a wave of ultrasonic vibration through the sample and calculating, from measured values for time of flight of the wave through the sample and its attenuation during that time, an identification parameter dependent on the type or concentration of the target species in the sample and independent of the distance travelled by the wave through the sample. The method is more convenient to use than existing identification techniques because of the removal of distance from the measurements and calculations necessary. The method is of particular use in identifying polymers, for example, in reclamation and recycling processes. An apparatus for performing the method is also disclosed.

Abstract: An ultrasonic leak detector which discriminates against leak signals originating from outside a desired detection zone. Incoming ultrasonic waves are divided into mutually exclusive low and high frequency signals, which signals are then processed to form an intensity ratio. The intensity ratio is compared to a pre-selected ratio corresponding to an ultrasonic source at the boundary of the detection. Ultrasonic leak signals originating from outside the desired detection zone are ignored. The presence of a leak within the detection zone is indicated by audio and/or visual devices.

Abstract: An apparatus and method are disclosed wherein a linear array of electromagnetic radiation emitting devices are arranged in association with a moving workpiece. Electromagnetic radiation emitted by the array is received by two or more receivers. Several non-contact measurements may be obtained on a workpiece using the present apparatus and methods.

Abstract: Power values of backscattered ultrasonic echoes from an interrogation region of a patient's body are stored in a 2-D envelope table. The region is thereby represented as a 2-D pattern of image elements. In a processing mode, these elements are grouped into processing windows. After row averaging of the power values for each window, a window attenuation coefficient is generated corresponding to a decay parameter of a non-linear decay model of local attenuation of the interrogation region as a non-linear function of the average positional power values for each row in the processing window. The coefficients are then used to scale the power values before scan conversion and display, and thus to compensate for local attenuation. The invention can also test for tissue heterogeneity by first defining convergence and non-convergence criteria. A rationalized gain control processor then iteratively estimates the window attenuation coefficients until either criterion is met.

Abstract: In a process for finding the value of parameters which change the resonance frequencies of microstructures wherein the microstructures include at least one membrane mounted at its periphery and wherein at least one resonance frequency of the microstructures is between 100 kHz and 100 MHz, the frequency of the characteristic resonance frequency of the microstructures is detected by exposing the microstructures to ultrasound and measuring the intensity of the ultrasound transmitted through, or reflected from, the microstructure and the value of the parameter is then determined by means of a calibration curve.

Abstract: An ultrasound densitometer is disclosed in which ultrasonic transducers are located spaced apart in a water bath into which the heel of a person may be inserted. The transit time of an ultrasonic pulse through the water and heel and the attenuation of the pulse may be measured to evaluate the physical properties of the bone in the heel. A central controller coordinates the ultrasonic measurement with the automatic filling and draining of the water bath to ensure hygienic and repeatable operation. The water may be preheated to reduce patient discomfort and to improve the reduced by preheating water in a separate pre-fill chamber during the previous scan. Gravity feed of the water reduces the complexity of the water handling and provides extremely quiet operation. A toe peg in the water bath, which fits between the patient's toes, and a calf support help to reduce patient motion during the measuring.

Abstract: A detector indicating ice formation on the wing of an aircraft or any planear surface, based on a thread-like or a tape-like transducer, through which an ultrasonic signal is transmitted at one end. The attenuation of the signal having passed through the thread is measured with a receiver at the opposite end while the thread is simultaneously being heated such that ice that may surround it melts again, the attenuation thus resuming its initial level.

Abstract: A method and apparatus for ultrasonically characterizing a polymer melt flowing in a predetermined direction between two opposed parallel surfaces spaced from one another to define a gap filled with polymer are disclosed. Ultrasonic pulses are propagated through the polymer melt between the two surfaces in a direction normal to the direction of flow for interaction with the polymer, the ultrasonic pulses having a duration such as to prevent successive echoes from overlapping with one another while reverberating between the two surfaces. The time delay between two echoes exiting from the polymer melt and generated from each pulse having interacted with the polymer is continuously monitored while simultaneously monitoring amplitude variations of the two echoes, to provide output signals representative of ultrasonic velocity and attenuation in the polymer melt. These output signals are processed to obtain data comprising ultrasonic velocity and attenuation values measured simultaneously as a function of time.

Abstract: A bone assessment apparatus provides a precise bone assessment based on the attenuation factor of an ultrasonic wave which has passed through a bone of a patient. A transmitting transducer and a receiving transducer are positioned at either side of the bone respectively, and an ultrasonic wave is irradiated to the bone, and passes therethrough. A transmitter/receiver provides an attenuation spectrum of the ultrasonic wave and determines a reference frequency f.sub.p peculiar to the patient at which the attenuation factor is minimum. A gradient .DELTA. of the attenuation spectrum is calculated based on the difference between the attenuation factor .alpha..sub.p at the reference frequency f.sub.p and the attenuation factor .alpha..sub.q at a frequency f.sub.q which is spaced apart by a predetermined value from the reference frequency f.sub.p. A density index .rho..sub.I is also calculated which is a gradient of the attenuation spectrum per unit thickness of the bone.

Abstract: A method for acoustic examination of a medium and detection of reflective targets includes a preliminary step of injecting a divergent sound beam into the medium from at least one transducer. Then the echo signals reflected by the medium and received by several transducers in an array are picked up. A time gate is used to select echoes coming from a particular zone of the medium. The echoes are stored, time-reversed and re-emitted. The signals newly reflected by the medium are stored and the time-reversal operation is repeated. After a final time reversal of rank 2n+1 (where n is a positive non-zero integer) over the full depth of the measurement time gate, the characteristics of the wavefront passing closest to the maxima of the signals are determined, advantageously in the form of a time distribution of the maxima. The characteristics can often be approximated with a polynomial law. An apparatus is disclosed for implementing the method.

Abstract: A method for determining bond integrity of a sealed package has a lid bonded to a container rim by detecting flaws in the bond between the lid and the container. The method comprises: i) positioning the container rim between an ultrasonic transmitter system and an ultrasonic receiver system; ii) ultrasonically coupling the transmitter system and the receiver system to the container rim; iii) transmitting ultrasound waves from the transmitter system through the container rim to the receiver system; iv) generating a signal representative of the ultrasound waves received by the receiver system; and v) analyzing the signal for predetermined signal characteristics representative of a flaw in the bond to identify a flawed package seal.

Abstract: An ultrasonic wave is applied to an anisotropic sample material in an initial direction and the intensity of the ultrasonic wave is measured on an opposite surface of the sample material by two adjacent receiving points located in an array of receiving points. A ratio is determined between the measured intensities of two adjacent receiving points, the ratio being indicative of an angle of flux deviation from the initial direction caused by an unknown applied load. This determined ratio is then compared to a plurality of ratios of a similarly tested, similar anisotropic reference material under a plurality of respective, known load conditions, whereby the load applied to the particular anisotropic sample material is determined. A related method is disclosed for determining the fiber orientation from known loads and a determined flux shift.

Abstract: An ultrasonic structure which has a thin planar sheet of material forming a Lamb wave propagation medium The propagation medium is coated with a gel. The structure may also include a Lamb wave generator for generating Lamb waves in the propagation medium and an output device for producing an electrical signal representative of the propagation characteristics of the Lamb waves propagating along the propagation medium. A measuring device can be included to measure selected characteristics of the output electrical signal. The propagation medium has some physical characteristics that are determined by the value of a measurand acting on the medium and the determined physical characteristics determine the propagation characteristics of the Lamb waves which are propagated along the medium. When the sensor is acted on by a measurand to determine the physical characteristics of the propagation medium, the characteristics of the electrical signal are also determined.

Abstract: An ultrasonic detector for detecting air in a fluid passage is disclosed. The detector comprises a transmitting crystal and complementary receiving crystal disposed around the fluid passage. A sweep oscillator is used to apply a variable-frequency signal to drive the transmitting crystal into resonance so that a burst of ultrasonic energy is released therefrom. The swept frequency range encompasses the resonant frequency of the transmitting crystal, ensuring that it resonates. If there is fluid in the passage, the ultrasonic energy causes a relatively high voltage to develop across the receiving crystal. Air in the passage attenuates transmission of the ultrasonic energy so that a low voltage signal is developed across the receiving crystal. A sensor circuit connected to the receiving crystal monitors the signal developed thereacross and in response to the magnitude of the signal, asserts a signal that indicates whether there is air or fluid in the passage.

Abstract: An ultrasonic sensor which has a thin planar sheet of material forming a Lamb wave propagation medium, the sheet having a thickness which is no greater than about twenty microns. The sensor also includes a Lamb wave generator for generating Lamb waves in the propagation medium and an output device for producing an electrical signal representative of the propagation characteristics of the Lamb waves propagating along the propagation medium. A measuring device is included in the sensor to measure selected characteristics of the output electrical signal. The propagation medium has some physical characteristics that are determined by the value of a measurand acting on the medium and the determined physical characteristics determine the propagation characteristics of the Lamb waves which are propagated along the medium. When the sensor is acted on by a measurand to determine the physical characteristics of the propagation medium, the characteristics of the electrical signal are also determined.

Abstract: A method and apparatus for sensing a liquid-solid phase transition event is provided which comprises an acoustic plate mode detecting element placed in contact with a liquid or solid material which generates a high-frequency acoustic wave that is attenuated to an extent based on the physical state of the material is contact with the detecting element. The attenuation caused by the material in contact with the acoustic plate mode detecting element is used to determine the physical state of the material being detected. The method and device are particularly suited for detecting conditions such as the icing and deicing of wings of an aircraft. In another aspect of the present invention, a method is provided wherein the adhesion of a solid material to the detecting element can be measured using the apparatus of the invention.

Abstract: An ultrasonic wave is emitted from an ultrasonic wave transducer for transmission to polymeric materials and received by an ultrasonic wave transducer for reception arranged at a predetermined distance away from the transducer for transmission. A propagation time of the ultrasonic wave and the level of the reception wave are measured during the process to heat or cool the polymeric materials. A state of the polymeric materials is discriminated on the basis of a characteristic curve which is determined by the propagation time and the reception wave level of the ultrasonic wave. In the case of measuring an asphalt paved road, when shoulder characteristics appear on the characteristic curve which is determined by the propagation time of the ultrasonic wave and the reception wave level, it is determined that a solid state in which a traffic lane can be opened was obtained.

Abstract: Apparatus for determining, through an interposed medium, the mechanical properties of a solid. The apparatus includes ultrasonic transmission apparatus for transmitting an ultrasonic wave through the interposed medium and the solid, wherein the solid has a surface, at least first and second ultrasonic receiver units, for receiving the ultrasonic wave, and apparatus for locating the receiver units such that a first receipt time of the ultrasonic wave from the surface to the first receiver unit is generally equivalent to a second receipt time from the surface to the second receiver unit.