Abstract: A sensor network is attached to a structure and employed to detect and analyze load changes. The sensor network has transducers, capable of acting as both passive sensors and active actuators, integrated within it. In a passive mode, the transducers detect load changes upon the structure, such as impacts. Upon detection of a load change, the transducers are engaged in an active mode to actively scan the impact area to determine the location and size of any resulting damage region. In this manner, passive and active systems are integrated within a single, convenient layer that possesses the best features of both active systems and passive systems.

Abstract: A surface wave chemical detector comprising at least one surface wave substrate, each of said substrates having a surface wave and at least one measurable surface wave parameter; means for exposing said surface wave substrate to an unknown sample of at least one chemical to be analyzed, said substrate adsorbing said at least one chemical to be sensed if present in said sample; a source of radiation for radiating said surface wave substrate with different wavelengths of said radiation, said surface wave parameter being changed by said adsorbing; and means for recording signals representative of said surface wave parameter of each of said surface wave substrates responsive to said radiation of said different wavelengths, measurable changes of said parameter due to adsorbing said chemical defining a unique signature of a detected chemical.

Abstract: A device for measuring thickness of an object has a vibration generator for generating vibrations in the object, a vibration detector for detecting vibrations generated in the object by the vibration generator and a frequency analyzer for calculating resonance frequency of the object. The vibration generator includes a light-emitting part which emits light towards the object to irradiate and to be absorbed by the object. A plurality of vibration detectors may be used and the frequency analyzer may include a sound speed analyzer for calculating speed of sound inside the object from vibrations detected by these plurality of vibration detectors.

Abstract: Two groups of inclined lines, which are included in a spurious wave scattering means, are formed at opposite angles with respect to each other in the vicinity of an upper edge of a substrate. The angles of the inclined lines are such that they are close to perpendicular toward the central portion of the substrate, and gradually decrease toward the edges thereof. In a similar manner, two other groups inclined lines, which are also included in the spurious wave scattering means, are formed at opposite angles with respect to each other, with gradually changing angles. The spurious waves that reach these regions are diffuse by the inclined lines, so that they are not propagated to converters (sensors). Three rectangular spurious wave scattering means, formed by inclined lines, inclined at angles other than 45°, also function to diffuse and eliminate spurious waves that propagate along the front surface of the substrate.

Abstract: An ultrasonic transducer for measuring a part with a coating having at least one acoustic transducer, and a buffer delay line having an impedance matched to an impedance of the coating.

Abstract: A method and apparatus for ultrasonic inspection of one or more objects in an object holder. In a first embodiment of the method, the objects are immersed in a tank containing coupling fluid and a flow of fluid is generated in the tank beneath the object holder, thereby producing a suction pressure that tends to hold the objects in the holder. Each object is insonified with ultrasound from an ultrasonic transducer and the ultrasound reflected from or transmitted through the object is sensed. In a further embodiment, the object to be inspected is moved between the upper and lower chambers of a scanning station, over a surface in the lower chamber. A coupling fluid is supplied to the upper chamber so that coupling fluid flows through one or more holes in the bottom of the upper chamber and fills the space between the ultrasound emitting surface of the ultrasonic transducer and the object to be scanned, thereby providing coupling for the ultrasound and tending the hold the objects in the object holder.

Abstract: The invention concerns a method for non-destructive ultrasonic control, combining time-of-flight diffraction (TOFD) and inclined longitudinal wave techniques, of weld joints assembling two abutted parts. The method consists of using the time-of-flight diffraction technique, displacing in the longitudinal or circumferential direction, along the weld joint to be controlled, at least one pair consisting of a first transducer and of a second transducer, one transmitting and the other receiving ultrasonic waves, these transducers being laterally positioned on either side of the joint to be controlled, these transducers comprising piezoelectric ceramics or crystals. Furthermore, it consists of displacing along the welded joint to be controlled, using the inclined longitudinal wave technique, at least a third transducer, so as to detect any defect of the joint located at a thickness ranging between 0.5 mm and 15 mm.

Abstract: A microfabricated mass-sensitive chemical preconcentrator actively measures the mass of a sample on an acoustic microbalance during the collection process. The microbalance comprises a chemically sensitive interface for collecting the sample thereon and an acoustic-based physical transducer that provides an electrical output that is proportional to the mass of the collected sample. The acoustic microbalance preferably comprises a pivot plate resonator. A resistive heating element can be disposed on the chemically sensitive interface to rapidly heat and release the collected sample for further analysis. Therefore, the mass-sensitive chemical preconcentrator can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

Abstract: A vibration information transmission apparatus for improving efficiency of field wiring of a vibration monitoring/analyzing system includes transmitters (11-1 to n) for converting vibration information from vibration sensors (2-1 to n) for detecting vibration of an object to be measured, into an electric signal and outputting the electric signal to a digital network (DN). The transmitters (11-1 to n) includes in the same casing, a transducer circuit (18) for converting the vibration information from the vibration sensors (2-1 to n) into an analog electric signal, an A/D conversion circuit (19) for converting the analog electric signal from the transducer circuit (18) into a digital signal, and a network interface (20) for outputting the digital signal from the A/D conversion circuit (19) to the digital network (DN).

Abstract: In order to arrange a heater effectively in a case containing ultrasonic sensors to melt frozen snow attached to the case assuredly to ensure the performance of the ultrasonic sensors, an ultrasonic sensor unit comprises ultrasonic sensors (9, 10), a case (11, 12) for containing the ultrasonic sensors, and a sheet component (20) arranged on an inner side of a bottom (12c) of the case to cover the bottom, and having a heater (22) buried in or mounted on it.

Abstract: A piezoelectric crystal element and a sensor utilizing the same are presented for use in a sensor device for identifying at least one foreign material from environment. The crystal element comprises at least one crystal resonator in the form of an inverted mesa structure, which has a membrane-like region and has a certain resonance frequency value. A surface region of the crystal resonator is modified by reactive molecules of a kind capable of interacting with the foreign material to yield a reaction product that effects a change in the resonance frequency of the crystal resonator from said certain resonance frequency value. This change is indicative of the identity and quantity of the foreign material.

Abstract: Disclosed herein is a method for imaging anisotropic media comprising selecting multiple points within the anisotropic media, which is to be imaged; determining an acoustic path between each selected point in the anisotropic media and a receiver position on the surface of the anisotropic media; calculating an acoustic wave velocity at all necessary points; determining an acoustic path length based on each selected point in the anisotropic media and the receiver position; determining a time delay for each acoustic wave between each image point and the receiver position on the surface of the anisotropic media; calculating a sum for each point selected based on the appropriate acoustic wave velocities and the acoustic path lengths; and generating an image of the anisotropic media using the coherent sums generated for each said image point selected.

Abstract: In order to measure a sound characteristic in a sound space, measurement sound is outputted to the sound space. Measurement sound data of a predetermined time period, which is prepared in advance, is divided into plural block periods, and plural block sound data are generated. A reproduction process of reproducing the plural block sound data in the order forming the measurement sound data is executed plural times by shifting the block sound data reproduced first by one for each time. Thereby, the measurement sound is outputted. When the above reproduction process is executed plural times, detected sound data corresponding to the block sound data reproduced at the identical reproduction order for each time are operated, and a sound characteristic is determined. Thereby, it becomes possible to measure the sound characteristic in the period shorter than the measurement sound data of the predetermined time period.

Abstract: A device 1 for measuring a mass comprises a vibrator 2, driving means 3A, 3B, 3C, 3D for exciting a basic vibration in the vibrator 2, detecting means 4A, 4B for detecting a displacement of vibration in the vibrator 2 and an adsorption film 5 capable of adsorbing a substance for detection. The mass is measured based on a difference between a detected value of the displacement of vibration obtained from the detecting means 4A, 4B when the mass is not measured and a detected value of the displacement of vibration obtained from the detecting means 4A, 4B when the mass is measured.

Abstract: An apparatus for generating and measuring bending vibration in a pipe buried underground or a pipe covered by insulating materials is disclosed. There is provided an apparatus for generating and measuring bending vibration in a non-ferromagnetic pipe without physical contact, comprising: a ferromagnetic strip adhered on a surface of the pipe; a coil wound around the surface of the pipe; two magnets for generating bias magnetic field, applied to the strip and parallel to the strip; a power source for supplying an electric current to the coil; and a measuring unit for measuring variation of voltage across the coil, the variation of the voltage being generated due to a strain according to inverse magnetostrictive effect, the strain being generated due to bending vibration, the bending vibration being generated due to deformation of the strip, the deformation being induced according to magnetostrictive effect as the power source supplies the electric current to the coil.

Abstract: Methods and systems for determining the resonance frequency of a resonator, using the Doppler effect. An interrogating sonic beam including a carrier frequency and one or more resonator exciting frequencies is directed at a resonator disposed in a measurement environment. Resonator vibrations are excited by the resonator exciting frequencies. The carrier frequency is modulated by the vibrating part(s) of the resonator. The returning signal is received and analyzed to determine the amplitude of the Doppler shifted sideband frequencies. The resulting data is processed to determine the resonator's resonance frequency. Using calibrated resonating sensors having a resonance frequency that varies as a function of a physical parameter in a measurement environment, the method and systems allow determining the value of the physical variable from the sensor's resonance frequency.

Abstract: An opto-acoustoelectric device encompasses a diaphragm having a diffraction grating, the diaphragm is susceptible to a vibration driven by an external force; a light source oriented to irradiate the diffraction grating; and a photo detector configured to detect the light diffracted by the diffraction grating and to convert the detected light into an electric signal. The electric signal corresponds to a displacement of the vibration in the diaphragm.

Abstract: Apparatus for non-destructively testing material to enable detection of any damage sites, comprising means for generating localized heating at any damage site in the material, and means for imaging the material to enable detection of any localized heating at the damage site.

Abstract: A method and apparatus for retaining a part in a carrier during an ultrasonic scan. The part is positioned above a first opening in a lower chamber while air is drawn out of a second opening in the lower chamber to apply suction to the lower surface of the part. An ultrasonic transducer is housed in an upper chamber that dispenses coupling fluid to the top surface of the object.

Abstract: A method for determining vibration amplitude limits of a mechanical device. The method comprises identifying a mechanical device and a frequency range for a spectrum to be analyzed, retrieving vibration spectra comprising individual spectrum for the mechanical device and the frequency range, calculating frequency for the individual spectrum, and identifying the individual spectrum with the smallest number of frequency lines. In addition, the method comprises calculating noise bandwidths and a largest noise bandwidth, removing outlier data, calculating conditional kernel density, and calculating vibration amplitude limits to detect faults in the mechanical device.