Abstract: A process for measuring a property of a sample is provided. The sample has an external surface enclosing an inner portion, and firstly, the sample is deformed by applying a predetermined non-contact pressure to deform a portion of the sample. Then a signal, which is at least suitable for transmission over the air, is directed towards the deformed portion of the sample, and further propagates through the external surface and the inner portion of the sample. Then an echoed signal generated by the inner portion of the sample in response to the propagation of the signal is detected; wherein the echoed signal incorporates information relating to a deformation of the inner portion of the sample. The property of the sample is determined from the deformation of the inner portion of the sample.

Abstract: A small photodetector type microphone (10) exhibiting excellent directivity without requiring any mirror surface. A diaphragm (27) vibrates in response to a sound pressure. An optical waveguide (28) is formed along the diameter of the diaphragm (27) and integral vibration of the optical waveguide (28) and the diaphragm (27) causes a variation in the quantity of light leaking from the optical waveguide (28) to the outside thus causing a variation in the quantity of light being transmitted across the optical waveguide (28). The optical waveguide (28) has one end side for introducing light into a light emitting elements (20) and the other end side for delivering light to a light receiving element (24). The light receiving element (24) outputs an electric signal related to the quantity of incident light.

Abstract: A vibration test system for structures comprises a vibration exciter that vibrates a real model portion, a load meter that measures a load, and a computer that receives a numerical model representing a numerical model portion. The computer includes a block that calculates a displacement, which is made in a predetermined time after completion of measurement, according to a load value and an external force value. A signal production block produces a command signal using as a target value the displacement calculated by the displacement calculation block. A step control block controls the displacement calculation block and signal production block so that they will act cyclically. The displacement calculation block uses an ?OS method to time integrate a solution of a vibrational equation.

Abstract: A system and method for determining whether leaks exist in a pressure vessel comprises measuring a mechanical response of the pressure vessel using any of an acoustic sensor and a vibration sensor; processing the mechanical response using a digital signal processor system; categorizing the processed mechanical response into events of interest and events not of interest; and determining if any of a ballistic impact and penetration of the pressure vessel has occurred based on the processed mechanical response, wherein the mechanical response comprises any of an acoustic response and a vibration response, wherein the events of interest comprise any of environmental events and ballistic events, wherein the categorizing comprises differentiating the environmental events from the ballistic events, and wherein the events not of interest comprise noise.

Abstract: A torsional vibration measuring instrument has a plurality of reflecting means (6, 7) arranged with stipulated intervals along surface of a rotator (5) of which torsional vibration is to be measured; a pulse light irradiating means (1, 2) for irradiating a repetitive pulse light beam to the reflecting means; and an outgoing-transmitting means (3, 4) for transmitting the irradiated pulse light beam. The torsional vibration measuring instrument also has a plurality of transmitting-receiving means (8, 9) for irradiating the transmitted pulse light beam to the reflecting means, and for receiving reflected pulse light beams which have been reflected by the reflecting means; and an incoming-transmitting means (3, 4) for transmitting the reflected pulse light beams which have been received.

Abstract: Ultrasonic pulser-receiver circuitry, for use with an ultrasonic transducer, the circuitry comprising a circuit board; ultrasonic pulser circuitry supported by the circuit board and configured to be coupled to an ultrasonic transducer and to cause the ultrasonic transducer to emit an ultrasonic output pulse; receiver circuitry supported by the circuit board, coupled to the pulser circuitry, including protection circuitry configured to protect against the ultrasonic pulse and including amplifier circuitry configured to amplify an echo, received back by the transducer, of the output pulse; and a connector configured to couple the ultrasonic transducer directly to the circuit board, to the pulser circuitry and receiver circuitry, wherein impedance mismatches that would result if the transducer was coupled to the circuit board via a cable can be avoided.

Abstract: A method and apparatus are disclosed for coupling ultrasound between an ultrasonic transducer and an object. A fluid cavity in an upper chamber has an inlet for receiving a flow of coupling fluid, a first aperture for admitting the ultrasonic transducer into the fluid cavity and a second aperture for dispensing coupling fluid from the fluid cavity to the object. The first and second apertures may be sized to restrict flow of coupling fluid from the fluid cavity. The focus of the ultrasound transducer may be varied by moving the ultrasonic transducer relative to the upper chamber.

Abstract: The inertial rotation sensor comprising a vibrating resonator associated with transducers defining a pair of control channels and a pair of detection channels, preferably comprises a single multiplexer member for all of the channels, the multiplexer member being associated with a processing unit generating cycles comprising control action times on each control channel followed by detection action times on each detection channel, with two succession action times being separated by a relaxation time.

Abstract: An arrangement for tracking resonant frequency of electrically resonant structures through a single channel includes a variable frequency oscillator associated with each resonant structure which provides an excitation signal of a variable frequency encompassing a possible resonant frequency of the associated resonant structure. Coupling device(s) are provided which connect each variable frequency oscillator to said resonant structure(s). An I-mixer is provided for each oscillator which forms a synchronous detector, a first input of each I-mixer being connected to its associated oscillator and a second input being connected to the coupling device, each I-mixer mixing the excitation signal from the associated variable frequency oscillator with a response signal generated by the resonant structure(s) in response to each excitation signal.

Abstract: A method and system for determining the fiber volume fraction of a composite structure. The system includes a unit for ultrasonically determining the porosity volume fraction in the article, and a unit for calculating the volume fraction of the fibrous reinforcement material in the article based on the porosity volume fraction in the article and the mass densities of the article and the fiber and matrix materials within the article. The method entails determining the mass density of the article, obtaining the mass densities of the fiber material and the matrix material, ultrasonically determining the porosity volume fraction in the article, and then calculating the volume fraction of the fibrous reinforcement material in the article based on the porosity volume fraction in the article, the mass density of the article, the mass density of the matrix material, and the mass density of the fiber material.

Abstract: Ultrasonic apparatus and associated methods for the in-line monitoring of melting, mixing and chemical reaction processes of materials inside an enclosed chamber having rotating elements associated therewith are presented. The chamber may be heated and the rotating elements may be blades and/or screws. The chamber may be a heating barrel and the materials may be polymer and polymer composites pellets, metal pellets and chemical compounds. Ultrasonic sensors, which are preferably coupled to a wall of the chamber, may be high temperature ultrasonic transducers attached to the external surface of the chamber or ultrasonic buffer rods embedded into the chamber and coupled to cooled ultrasonic transducers. These sensors are operated in the reflection mode and are placed over the rotating elements. The number and locations of the sensors depend on applications.

Abstract: A gas detector and process for detecting a fluorine-containing species in a gas containing same, e.g., an effluent of a semiconductor processing tool undergoing etch cleaning with HF, NF3, etc. The detector in a preferred structural arrangement employs a microelectromechanical system (MEMS)-based device structure and/or a free-standing metal element that functions as a sensing component and optionally as a heat source when elevated temperature sensing is required. The free-standing metal element can be fabricated directly onto a standard chip carrier/device package so that the package becomes a platform of the detector.

Abstract: A method and apparatus for monitoring a condition having a known relation to, or influence on, the transit time of a cyclically-repeating energy wave moving through a transmission channel, by: (a) transmitting a cyclically-repeating energy wave through the transmission channel from a transmitter at one end to a receiver at the opposite end; (b) continuously changing the frequency of the transmitter according to changes in the monitored condition while maintaining the number of waves in the transmission channel as a whole integer; and (c) utilizing the changes in frequency of the transmitter to provide a continuous indication of the monitored condition. Operation (b) is preferably performed by detecting a predetermined fiducial point in each cyclically-repeating energy wave received by the receiver, but may also be performed by the use of a phase-locked loop circuit, to maintain the number of energy waves in the loop of the transmission channel as a whole integer.

Abstract: A method and apparatus (10) is provided which employs phase or amplitude modulated electromagnetic probing waves (20) (in optical or microwave frequency ranges or both) emitted toward a vibrating object (8). The optical and/or microwave probing signals (20) remotely irradiate an object (8) of interest. The object (8) reflects and/or scatters the probing wave (20) toward a receiver (22). The reflected/scattered modulated signal (24) is received with a remote sensor (receiver) (22). Vibration causes additional phase modulation to the probing wave (20). At the receiving end, the signal is demodulated to extract and analyze the vibration waveform (26,28). The present invention can be utilized for nondestructive testing, monitoring of technological processes, structural integrity, noise and vibration control, mine detection, etc.

Abstract: The present invention provides an ultrasonic transducer structure, comprising a first ultrasonic transducer element (1), arranged and operable for transmitting an ultrasonic signal from a front face of the structure, damping material (2) at the back of the first ultrasonic transducer element (1), and a second ultrasonic transducer element (3) in or on the damping material behind the first ultrasonic transducer element (1), arranged and operable to receive sound energy propagated through the damping material (2) when the first ultrasonic transducer element (1) is operated to transmit an ultrasonic signal from the front face.

Abstract: An apparatus comprises a variable acoustic source and a microphone, both acoustically coupled to a volume having a fluid region and an air region. The apparatus also can include a processor to determine a volume of the air region based on signals received from the microphone and the variable acoustic source. A fluid valve is coupled to the processor, and is configured to allow an amount of fluid to exit the fluid region associated with the volume of the air region. An atomizer, coupled to the fluid region, is configured to aerosolize at least a portion of the fluid.

Abstract: An acoustic sensor for monitoring machining processes in machining tools, e.g. grinding machines, includes a stationary unit, or stator (21) and a rotating unit, or rotor (23), the latter being coupled, for instance, to the grinding wheel and rotating with it. The rotor includes a support (45;45?) and a piezoelectric transducer (33). The position of the transducer is defined and locked without using glues by means of mechanical elements (48, 53, 54; 63, 64; 74, 78) that may include elastic elements such as springs. The rotor also includes a printed circuit board (55), connected to the piezoelectric transducer, with a charge amplifier (37) for amplifying the output signal of the piezoelectric transducer. The rotor is electrically coupled to the stator by means of transformer type couplings (30, 31).

Abstract: Determining whether a device is defective by analyzing the sound signals generated by the device. Digital samples are generated to represent the sound signals. Digital samples are transformed from the time domain to the frequency domain to generate a frequency spectrum. By comparing the levels of intensity at a corresponding frequency to the threshold levels of intensity, defective devices can be determined.

Abstract: The invention relates to an ultrasonic sensor system, especially for controlling a resistance welding process. Said system comprises at least one receiver which is used to detect the ultrasonic signals from the area to be examined. At least two piezoelectric sensors (31, 32) are used as a receiver and are arranged in such a way that their polarization direction vectors indicate various directions, said vectors being projected in a plane perpendicular in relation to the propagation direction of an ultrasonic wave to be detected.

Abstract: A method is disclosed for predicting attenuation in real time while drilling using a portable continuous wave technology (CWT) tool to obtain amplitude spectra as a function of frequency for the cuttings at the rig site. Attenuation is predicted, and plotted as a function of frequency to monitor hydrocarbon content changes, fluid front moves, and pressure mapping or plotting attenuation as a function of depth to calibrate high resolution seismic data and interpret amplitudes for formation permeability determination.