Vibration Velocity (e.g., Echo Timing) Patents (Class 374/119)
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Patent number: 7404671Abstract: Acoustic temperature measurement at a remote location is provided. An acoustic source transmits acoustic radiation to an acoustic receiver along an acoustic path. The path passes through or near the remote location. The temperature is non-uniform along the path. A change in an integrated acoustic delay between the source and receiver along the path is measured. This acoustic delay can be either a phase velocity delay or a group velocity delay. The temperature at the remote location is determined by relating the measured change in integrated acoustic delay to the remote location temperature with a combined thermal-acoustic model. The combined model relates temperature to acoustic propagation velocity along the path. The combined model preferably includes temperatures of the source and receiver locations, and a heat source geometry at the remote location.Type: GrantFiled: March 9, 2006Date of Patent: July 29, 2008Assignee: Luna Innovations IncorporatedInventors: Joseph S. Heyman, Eugene V. Malyarenko
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Patent number: 7376522Abstract: In an exemplary implementation of a method and system for determining the direction of fluid flow, one or more sound transducers are positioned in proximity to a conduit, each such sound transducer generating a signal representative of a selected characteristic of acoustic waves emanating from the conduit. Such signals are collected and analyzed to determine a threshold value for the selected characteristic (e.g., frequency) indicative of a change in the direction of fluid flow through the conduit. Based on whether subsequent measurements of the selected characteristic (e.g., frequency) are above or below the threshold value, the direction of fluid flow can be predicted and/or a change in the operational state of a component associated with the conduit can be identified.Type: GrantFiled: September 6, 2006Date of Patent: May 20, 2008Assignee: Genscape Intangible Holding, Inc.Inventors: Sterling Lapinski, Deirdre Alphenaar, Susan Olson
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Publication number: 20080107150Abstract: A method for determining the temperature of an away-facing surface of an object, wherein at least one ultrasonic pulse is transmitted through a surface of the object facing a transmitter/receiver unit into said object; the at least one ultrasonic pulse is reflected at least partially in the direction of the transmitter/receiver unit on the surface of the object facing away from the transmitter/receiver unit; and the reflected part of the at least one transmitted ultrasonic pulse is received by the transmitter/receiver unit. At least one temperature value for the object surface facing the transmitter/receiver unit is also determined; at least one value is determined for the propagation time of the at least one ultrasonic pulse through the object, and at least one temperature value for the object surface facing away from the transmitter/receiver unit is determined by the at least one temperature value for the object surface facing the transmitter/receiver unit and the at least one propagation time value.Type: ApplicationFiled: September 16, 2005Publication date: May 8, 2008Inventors: Hans-Gerd Brummel, Uwe Linnert, Klaus Newerla, Michael Willsch
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Patent number: 7266989Abstract: A sensor system immersible in an ambient-fluid for sensing at least two conditions of the ambient fluid, includes a sealed chamber filled with a reference fluid of a known composition and/or pressure, and two acoustic transmission channels, one including the reference fluid, and the other including the ambient fluid. Measuring circuitry measures (a) the transit time of an energy wave through one transmission channel to determine the temperature of the fluid within the sealed chamber and thereby the temperature of the ambient fluid; and (b) the transit time of an energy wave through the other transmission channel to determine the composition and/or the pressure of the ambient fluid.Type: GrantFiled: May 10, 2005Date of Patent: September 11, 2007Assignee: Nexense Ltd.Inventor: Arie Ariav
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Patent number: 7156551Abstract: Ultrasound transducer temperatures are measured in response to a temperature dependent property of the ultrasound transducer. The temperature is measured without addition of new electronics or hardware retrofits of the transducer. By implementing software and/or hardware on the ultrasound system rather than the transducer, the temperature is measured in order to provide a level of fault protection. The upgraded or new ultrasound system uses either old or new transducers while still providing temperature measurement. For example, the temperature of the lens or window is measured as a function of changes in attenuation or acoustic velocity. The receive beamformer already implemented on many ultrasound systems is used to measure a temperature dependent property of the lens or window. As another example, the dielectric constant or capacitance of one or more transducer elements is measured using additional hardware in the ultrasound system.Type: GrantFiled: October 6, 2003Date of Patent: January 2, 2007Assignee: Siemens Medical Solutions USA, Inc.Inventors: Bhaskar Ramamurthy, John Douglas Marshall, Sevig Ayter, Jan-Ulco Kluiwstra, Jerry D. Hopple
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Patent number: 6960019Abstract: A method of monitoring a temperature condition includes inputting a light pulse into a fiber optic cable and receiving a reflection signal that arises from said input light pulse in said fiber optic cable. A temperature condition along the fiber optic cable and a location of the temperature condition along the fiber optic cable is determined based on said reflection signal.Type: GrantFiled: November 14, 2003Date of Patent: November 1, 2005Assignee: Airbus Deutschland GmbHInventor: Hans-Joachim Dammann
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Patent number: 6945692Abstract: A system for monitoring a temperature condition includes a fiber optic cable, a light emitting device coupled to the fiber optic cable and configured to input a light pulse into the fiber optic cable, and an optical receiver coupled to the fiber optic cable and configured to receive a reflection signal that arises from the input light pulse in the fiber optic cable. A processor of the system is configured to determine a temperature condition along the fiber optic cable and a location of the temperature condition along the fiber optic cable based on the reflection signal.Type: GrantFiled: November 14, 2003Date of Patent: September 20, 2005Assignee: Airbus Deutschland GmbHInventor: Hans-Joachim Dammann
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Patent number: 6837109Abstract: Longitudinal and shear ultrasonic waves are generated inside a material by irradiating a laser beam onto a first surface, e.g., incident surface, of the material. An ultrasonic longitudinal wave and a mode converted wave reflected by a second surface, e.g., a bottom surface, of the material are detected, and times of flight of the ultrasonic longitudinal wave and the mode converted wave are measured. A thickness of the material is measured based on the times of flight and a correlation, obtained in advance, between longitudinal and shear wave velocities of the material and temperature of the material.Type: GrantFiled: November 5, 2002Date of Patent: January 4, 2005Assignees: Kawasaki Steel Corporation, Lasson Technologies, Inc.Inventors: Makoto Okuno, Hideo Sato, Marvin B. Klein, Bruno F. Pouet
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Publication number: 20040258127Abstract: Ultrasound transducer temperatures are measured in response to a temperature dependent property of the ultrasound transducer. The temperature is measured without addition of new electronics or hardware retrofits of the transducer. By implementing software and/or hardware on the ultrasound system rather than the transducer, the temperature is measured in order to provide a level of fault protection. The upgraded or new ultrasound system uses either old or new transducers while still providing temperature measurement. For example, the temperature of the lens or window is measured as a function of changes in attenuation or acoustic velocity. The receive beamformer already implemented on many ultrasound systems is used to measure a temperature dependent property of the lens or window. As another example, the dielectric constant or capacitance of one or more transducer elements is measured using additional hardware in the ultrasound system.Type: ApplicationFiled: October 6, 2003Publication date: December 23, 2004Applicant: Siemens Medical Solutions USA, Inc.Inventors: Bhaskar Ramamurthy, John Douglas Marshall, Sevig Ayter, Jan-Ulco Kluiwstra, Jerry D. Hopple
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Patent number: 6789426Abstract: There is described a method and apparatus for measuring temperature of a fluid in a microchannel of the type having spaced walls. An ultrasonic transducer transmits ultrasonic waves transmitted from one wall to the opposite wall. A processor determines the time-of-flight of the ultrasonic waves from the one wall and reflected to the opposite wall to the one wall. The processor converts the time-of-flight to velocity by dividing the distance between walls by the time-of-flight. The processor converts velocity to temperature from the relationship of velocity to temperature in the fluid.Type: GrantFiled: July 17, 2002Date of Patent: September 14, 2004Assignee: Board of Trustees of the Leland Stanford Junior UniversityInventors: Goksen G. Yaralioglu, Arif S. Ergun, Hemanth Jagannathan, Butrus T. Khuri-Yakub
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Patent number: 6764215Abstract: The present invention relates to a method, a measuring cell and a system for measuring very small heat changes in a sample. The system comprises a measuring cell 16 for containing the sample during the measurement process, at least one electromagnetic radiation unit 14 for radiating one or several samples with modulated monochromatic or polychromatic radiation 46 inside said measuring cell 16. Said measuring cell 16 comprises at least one acoustic transducer 22 for generating a first output signal V(t) and at least one heat measuring device 24 for generating a second output signal T(t). Both signals are connectable to a combining unit 18 that generates an information signal by means of a reference signal f(t). Said information signal is connectable to a signal processing unit 20 for determining at least one relevant reaction parameter as a function of the measured heat change.Type: GrantFiled: June 28, 2002Date of Patent: July 20, 2004Assignee: Amersham Biosciences UK Ltd.Inventors: Phil Meyler, Rudi Labarbe
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Patent number: 6726359Abstract: An apparatus for detecting the temperature of a room (2) includes means (4) for generating and receiving sound waves, means (5) for determining the transit time of the sound waves for a certain distance (x) in the room (2) and means (10) for calculating the temperature (U) of the room (2) by means of the ascertained transit time (t) of the sound waves for the distance (x) in the room (2). An approximation procedure for ascertaining the distance (x) is automatically executed. The temperature (U) ascertained in that way corresponds to a mean room temperature over the distance (x).Type: GrantFiled: September 21, 2001Date of Patent: April 27, 2004Assignee: Siemens Building Technologies AGInventor: Yves Lüthi
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Publication number: 20030029242Abstract: There is described a method and apparatus for measuring temperature of a fluid in a microchannel of the type having spaced walls. An ultrasonic transducer transmits ultrasonic waves transmitted from one wall to the opposite wall. A processor determines the time-of-flight of the ultrasonic waves from the one wall and reflected to the opposite wall to the one wall. The processor converts the time-of-flight to velocity by dividing the distance between walls by the time-of-flight. The processor converts velocity to temperature from the relationship of velocity to temperature in the fluid.Type: ApplicationFiled: July 17, 2002Publication date: February 13, 2003Inventors: Goksen G. Yaralioglu, Arif S. Ergun, Hemanth Jagannathan, Butrus T. Khuri-Yakub
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Patent number: 6517240Abstract: The ultrasonic thermometer system of the present invention includes a rod or probe of high temperature, grain-stabilized material that has a magnetostrictive or piezoelectric transducer bonded to one end. The transducer is excited by a transducer driver, creating short, periodic, ultrasonic pulses that travel down the length of the rod in a “pulse-echo” fashion. Along the length of the rod, circumferential grooves are cut which reflect some of the ultrasonic energy back to the transducer thus creating a reflected or echo signal. Two such reflected signals from two adjacent grooves, or a signal from one groove and a signal from the end of the rod, establish a temperature zone. This is the zone of interest to the user, which would be inserted into the user's process that needs to have the temperature monitored.Type: GrantFiled: November 5, 1999Date of Patent: February 11, 2003Assignee: DuraMetrics, Inc.Inventors: Glenn T. Herb, Charles Fendrock
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Patent number: 6481287Abstract: An acoustic temperature measurement system for pipeline fluids comprises a loudspeaker (16) with spaced microphone (18) in a sealed pipe (10) with end cap (11). A computer arrangement (22) provides a tone burst signal which drives the speaker via power amplifier (21) and the outgoing and reflected signal is detected by the microphone (18) and following amplification in amplifier (20) passes to the computer (22) for processing. The signals are processed to determine phase relationships indicative of temperature and can be used in correcting leakage measurement readings.Type: GrantFiled: February 15, 2001Date of Patent: November 19, 2002Assignee: BG Transco PLCInventors: Roger Philip Ashworth, Mark Harper
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Publication number: 20020131472Abstract: An acoustic pyrometer measures the average gas temperature across a wide space of known distance, especially turbulent, high temperature gas loaded with caustic particulates. It includes an acoustic signal generator that generates a high amplitude acoustic signal with a short rise time and a detector positioned adjacent the signal generator that detects the onset of the acoustic signal in the signal generator and generates a first electrical signal corresponding in time to the onset of the acoustic signal in the signal generator. A receiver, positioned across the space from the signal generator, receives acoustic signals from the space and generates electrical signals corresponding to amplitude and frequency of the acoustic signals received in the receiver.Type: ApplicationFiled: December 14, 2001Publication date: September 19, 2002Inventors: Dean E. Draxton, James G. Droppo, Richard E. Hogle, George Kychakoff
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Publication number: 20020101905Abstract: An apparatus for detecting the temperature of a room (2) includes means (4) for generating and receiving sound waves, means (5) for determining the transit time of the sound waves for a certain distance (x) in the room (2) and means (10) for calculating the temperature (U) of the room (2) by means of the ascertained transit time (t) of the sound waves for the distance (x) in the room (2). An approximation procedure for ascertaining the distance (x) is automatically executed. The temperature (U) ascertained in that way corresponds to a mean room temperature over the distance (x).Type: ApplicationFiled: September 21, 2001Publication date: August 1, 2002Applicant: Siemens Building Technologies AGInventor: Yves Luthi
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Patent number: 6296385Abstract: A probe for measuring the viscosity and/or temperature of high temperature liquids, such as molten metals, glass and similar materials comprises a rod which is an acoustical waveguide through which a transducer emits an ultrasonic signal through one end of the probe, and which is reflected from (a) a notch or slit or an interface between two materials of the probe and (b) from the other end of the probe which is in contact with the hot liquid or hot melt, and is detected by the same transducer at the signal emission end. To avoid the harmful effects of introducing a thermally conductive heat sink into the melt, the probe is made of relatively thermally insulative (non-heat-conductive) refractory material. The time between signal emission and reflection, and the amplitude of reflections, are compared against calibration curves to obtain temperature and viscosity values.Type: GrantFiled: May 12, 1998Date of Patent: October 2, 2001Assignee: Mississippi State UniversityInventors: Krishnan Balasubramaniam, Vimal Shah, R. Daniel Costley, Jagdish P. Singh
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Patent number: 6269700Abstract: An acoustic detector which includes at least one emitter unit with a solid tapered profile spike (C) associated with an element (X) for exciting the spike so as to propagate ultrasound waves in an antisymmetrical propagation mode in the spike. The device also emits waves into a surrounding gas. At least one receive unit includes a tapered profile solid spike associated with the detector for receiving the ultrasound waves.Type: GrantFiled: April 28, 1999Date of Patent: August 7, 2001Inventor: Jean-Pierre Nikolovski
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Patent number: 6112595Abstract: An apparatus and method are disclosed for characterizing semiconductor wafers or other test objects that can support acoustic waves. Source and receiving transducers are configured in various arrangements to respectively excite and detect acoustic waves (e.g., Lamb waves) in a wafer to be characterized. Signals representing the detected waves are digitally processed and used to compute a measurement set correlated with the waves' velocity in the wafer. A characterization sensitivity is provided that describes how different wafer characteristics of interest vary with changes in the propagation of the acoustic waves. Using the characterization sensitivity and measurement sets computed at a setup time when all wafer characteristics are known and one or more process times when at least one of the characteristics is not known the perturbation in wafer characteristics between the setup and the process times can be determined.Type: GrantFiled: October 18, 1999Date of Patent: September 5, 2000Assignee: Sensys Instruments CorporationInventors: Fred E. Stanke, Butrus T. Khuri-Yakub, Hung Pham, Talat Hasan
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Patent number: 6026688Abstract: There is provided a monitor and method for monitoring the condition of a photoresist film on a wafer during baking in which the phase of high frequency ultrasonic pulses reflected from the wafer/photoresist interface provides an indication of the condition of the photoresist film.Type: GrantFiled: October 3, 1997Date of Patent: February 22, 2000Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Buhrus T. Khuri-Yakub, Susan Morton, F. Levent Degertekin
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Patent number: 5996415Abstract: An apparatus and method are disclosed for characterizing semiconductor wafers or other test objects that can support acoustic waves. Source and receiving transducers are configured in various arrangements to respectively excite and detect acoustic waves (e.g., Lamb waves) in a wafer to be characterized. Signals representing the detected waves are digitally processed and used to compute a measurement set correlated with the waves' velocity in the wafer. A characterization sensitivity is provided that describes how different wafer characteristics of interest vary with changes in the propagation of the acoustic waves. Using the characterization sensitivity and measurement sets computed at a setup time when all wafer characteristics are known and one or more process times when at least one of the characteristics is not known the perturbation in wafer characteristics between the setup and the process times can be determined.Type: GrantFiled: April 30, 1997Date of Patent: December 7, 1999Assignee: Sensys Instruments CorporationInventors: Fred E. Stanke, Butrus T. Khuri-Yakub, Hung Pham, Talat Hasan
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Ultrasonic sensors for on-line monitoring of castings and molding processes at elevated temperatures
Patent number: 5951163Abstract: 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.Type: GrantFiled: October 16, 1996Date of Patent: September 14, 1999Assignee: National Research Council of CanadaInventors: Cheng-Kuei Jen, Ky Thanh Nguyen, Bin Cao, Hao Wang, Chee Ang Loong -
Patent number: 5624188Abstract: A thermometer using the temperature dependance of the speed of sound, measures the average temperature along a path traversing an open environment containing a medium. A transmitting transducer, coupled to a signal generator and placed at a first point in the medium, produces a burst of sound of predetermined frequency and duration. The sound burst travels through the medium to a second point, located a predetermined distance from the first. At the second point, a passive sound reflector, or an active apparatus, produces a returning sound burst. A receiving transducer, positioned close to the transmitting transducer, receives the returned sound. A detection circuit, coupled to the receiving transducer, indicates the presence of the returned sound burst. A timer, with connections to the signal generator and the detection circuit, measures the elapsed time for the round trip of the sound.Type: GrantFiled: October 20, 1994Date of Patent: April 29, 1997Inventor: David A. West
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Patent number: 5469742Abstract: An acoustic temperature and/or film thickness monitoring system for semiconductor wafers in which the velocity of acoustic waves in the wafer is employed to measure temperature and/or thickness.Type: GrantFiled: March 9, 1993Date of Patent: November 28, 1995Inventors: Yong J. Lee, Butrus T. Khuri-Yakub, Krishna C. Saraswat
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Patent number: 5437506Abstract: A system for measuring the "time of flight" or transfer time of a sound wave in a gas by using the relation between the gas temperature and the velocity of the sound wave in the gas, and calculating therefrom the temperature of the gas. The system comprises an emitter, which generates a sound which is coherent in phase, at one frequency or a group of frequencies; a self-correlating decoder and a receiver, which is associated with the emitter, and which sends the sound to a filter system and to an assembly controlled by a microprocessor, which processes the signal coming out of the filter system in a shape similar to a Hamming wave shape in order to determine the absolute maximum value and therefrom determine the transfer time. With this knowledge, it is easy to relate the transfer time to the distance traveled between the emitter and receiver and the known properties of the gas, in order to arrive at the temperature of the gas through which the sound has been sent.Type: GrantFiled: February 5, 1993Date of Patent: August 1, 1995Assignee: ENEL (Ente Nazionale per l'Energia Elettrica) & CISE S.p.A.Inventor: Antonio Gray
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Patent number: 5360268Abstract: A temperature measuring apparatus measures the temperature of a medium according to the propagation time of ultrasonic waves propagated for a predetermined distance through the medium. The apparatus has a transmitter 11, 12 for transmitting ultrasonic waves having a fixed frequency at predetermined timing and a receiver 13, 14, 15 for receiving the ultrasonic waves and providing a received signal. A delay time detector 24 detects, in response to the received signal, a delay time between the transmission and reception of the ultrasonic waves and a wave number calculator 21 calculates an integral wave number according to the delay time and a period of the ultrasonic waves. A phase difference detector 25 detects a phase difference between the transmitted and received ultrasonic waves modulating the received signal with a frequency that is sufficiently higher than the frequency of the ultrasonic waves.Type: GrantFiled: November 1, 1993Date of Patent: November 1, 1994Assignees: Nippon Soken Inc., Nippondenso Co., Ltd.Inventors: Yasushi Hayashi, Koji Numata, Kazutoshi Nishizawa
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Patent number: 5349859Abstract: The transit time of acoustic waves between a generator and a receiver positioned across a fluid chamber is determined by generating acoustic waves using a self-purging pneumatic sound generator, a transducer adjacent the outlet of the sound generator, and a receiving transducer positioned away from the sound generator outlet so that the acoustic waves received by the receiving transducer pass through a portion of the fluid. The electrical signals generated by the transmitting transducer and the receiving transducer are processed to obtain the impulse response of these electrical signals, and the point of maximum value is determined. This point of maximum value corresponds to the arrival time of the acoustic waves at the receiving location. The transit time determination may be used to calculate the fluid temperature or other parameters.Type: GrantFiled: November 15, 1991Date of Patent: September 27, 1994Assignee: Scientific Engineering Instruments, Inc.Inventor: John A. Kleppe
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Patent number: 5286109Abstract: A distributed temperature sensor comprises an elongate ultrasonic waveguide having a number of zones along its length, each zone having a grating formed on it. This is typically achieved by incorporating uniformly spaced notches or bands (or collars) throughout the zone. The grating spacing in each zone is different, so that each grating reflects a characteristic frequency. This frequency varies as the temperature of the zone varies, so if wide-band ultrasonic pulses are launched into the waveguide, the temperature of each zone can be determined from the reflected frequencies.Type: GrantFiled: February 16, 1993Date of Patent: February 15, 1994Assignee: Schlumberger Industries LimitedInventors: Paul A. Hanscombe, Paul N. Richards
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Patent number: 5226730Abstract: A method and apparatus for measuring the internal temperature of a work piece comprises an excitation laser for generating laser pulses which are directed through a water cooled probe, and in an optical fiber, to a first surface of the work piece. The laser is of sufficient intensity to ablate the surface of the work piece, producing a displacement and a resulting ultrasonic pulse which propagates within the thickness of the work piece to an opposite surface. The ultrasonic pulse is reflected from the opposite surface and returns to the first surface to create a second displacement. A second continuous laser also shines its light through an optical fiber in the probe into the first surface and is used in conjunction with signal processing equipment to measure the time between the first and second displacements.Type: GrantFiled: May 27, 1992Date of Patent: July 13, 1993Assignee: The Babcock & Wilcox CompanyInventor: John W. Berthold
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Patent number: 5218858Abstract: A flexural acoustic wave sensing method and efficient, simple, miniature and economical ultrasonic devices using thin rods are presented. The diameter of the thin rod is less than one acoustic wavelength. The lowest order flexural acoustic wave, F.sub.11 mode, propagating along such thin rods is used. The thin rod materials can be metals, glasses, ceramics, polymers and single crystals. Any external disturbance which can alter the propagation characteristics of F.sub.11 mode may be monitored by recording such variation. Fiber acoustic interferometers, which are built by jointing two thin rods, can offer high sensitivity. These devices are primarily used for sensors.Type: GrantFiled: April 3, 1991Date of Patent: June 15, 1993Assignee: National Research Council of CanadaInventor: Cheng-Kuei Jen
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Patent number: 5214955Abstract: A measuring apparatus uses a fixed frequency oscillator to measure small changes in the phase velocity ultrasonic sound when a sample is exposed to environmental changes such as changes in pressure, temperature, etc. The invention automatically balances electrical phase shifts against the acoustical phase shifts in order to obtain an accurate measurement of electrical phase shifts.Type: GrantFiled: August 26, 1991Date of Patent: June 1, 1993Assignee: The United States of America as represented by the United States National Aeronautics and Space AdministrationInventors: William T. Yost, Peter W. Kushnick, John H. Cantrell
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Patent number: 5181778Abstract: A method and apparatus for the in-process measurement of internal particulate temperature utilizing ultrasonic tomography techniques to determine the speed of sound through a specimen material. Ultrasonic pulses are transmitted through a material, which can be a multi-phase material, over known flight paths and the ultrasonic pulse transit times through all sectors of the specimen are measured to determine the speed of sound. The speed of sound being a function of temperature, it is possible to establish the correlation between speed of sound and temperature, throughout a cross-section of the material, which correlation is programmed into a computer to provide for a continuous in-process measurement of temperature throughout the specimen.Type: GrantFiled: September 30, 1991Date of Patent: January 26, 1993Assignee: EG&G Idaho, Inc.Inventor: Laurence S. Beller
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Patent number: 5080495Abstract: Disclosed is a method for measuring the thermal diffusivity in the thickness direction of a thin sample plate, which has the steps of forming a conductive thin layer on at least one surface of said thin sample plate to allow the thin film to function as an ac heater generating joule heat, applying an ac current modulated with a given modulation frequency to the ac heater (conductive thin layer) so as to produce ac joule-heating, generating an oscillation response corresponding to said ac joule-heating on the opposite surface of the ac heater, and measuring the phase shift between said oscillation response, and the ac joule-heating, thereby obtaining the thermal diffusivity in the thickness direction of said sample plate. Apparatus useful for the method are also disclosed.Type: GrantFiled: August 28, 1990Date of Patent: January 14, 1992Assignee: Mitsui Toatsu Chemicals, Inc.Inventors: Toshimasa Hashimoto, Akira Miyamoto, Kohei Shizuka, Teruo Hyugaji
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Patent number: 5044769Abstract: An ultrasonic distributed temperature sensor comprises an elongate ultrasonic waveguide in the form of steel or nickel wire 0.16 cm in diameter and up to 10 meters long, which is strung around the area whose temperature is to be monitored, eg an aircraft engine. The wire is provided with discontinuities in the form of annuli welded on to it to form annular flanges, which serve to partially reflect ultrasonic pules launched into one end of the wire. These flanges, known as "posi-notches", divide the waveguide, and thus the area to be monitored, into a number of zones, the size of each zone being determined by the spacing of the adjacent flanges defining it. In operation, the temporal spacing of each pair of successive partially reflected pulses is a measure of the average temperature of the zone defined by the flanges producing that pair of pulses.Type: GrantFiled: January 9, 1990Date of Patent: September 3, 1991Assignee: Schlumberger Industries LimitedInventors: Konrad Kulczyk, George W. Smith
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Patent number: 5022014Abstract: An ultrasonic fire detector comprises an elongate ultrasonic waveguide, e.g. in the form of a wire, which is arranged to be strung around the area to be monitored for fire. An ultrasonic pulse generator launches longitudinal ultrasonic pulses into one end of the waveguide, for reflection from the far end. The waveguide is arranged such that local heating due to a fire changes its acoustic impedance at the location of the local heating, the change in acoustic impedance being sufficient to produce partial reflection of the ultrasonic pulses. Detection of the partially reflected pulses thus indicates the presence of a fire, and their time of arrival gives the location of the fire along the waveguide. The acoustic impedance change can be produced by providing the waveguide with notches filled with low melting-point alloy, by applying a temperature-induced stress to the waveguide, or simply by the temperature gradient caused by the fire.Type: GrantFiled: June 14, 1989Date of Patent: June 4, 1991Assignee: Schlumberger Industries LimitedInventors: Konrad Kulczyk, Malcolm P. Perks, George W. Smith
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Patent number: 5016474Abstract: An ultrasonic piezoelectric transducer and a method for measuring and/or monitoring various physical properties of a member, in-situ, are disclosed. The transducer includes a sleeve which is received in a blind bore provided in the member, a piezoelectric element positioned within the blind bore, and an aligning spacer means interposed between the end of the sleeve and the piezoelectric element. By the application of appropriate voltage pulses to the piezoelectric element causing interrogating signals to be applied to the member, and the measurement of the time interval between the application of an interrogating signal and the receipt of a return signal from the member, various physical properties of the member and structural information regarding same can be determined.Type: GrantFiled: March 7, 1990Date of Patent: May 21, 1991Assignee: J. W. Harley Inc.Inventors: Dov Hazony, Richard E. Berris, Jr.
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Patent number: 4972178Abstract: In a fire monitoring system for monitoring the occurrence of a fire in which a space to be monitored is imaginarily subdivided into plural subspaces so that plural channels passing through the subspaces are set so as to intersect to each other in a lattice form. The propagation speed of ultrasonic waves propagating through each of the channels is measured, on the basis of which the propagation speed of the ultrasonic waves in each of the subspaces is calculated in the same manner as the solution for each element of a matrix is obtained, and then the temperature in each of the subspaces is obtained. By providing the system with a humidity sensor, the temperature for a dry condition is obtained.Type: GrantFiled: April 4, 1989Date of Patent: November 20, 1990Assignee: Nittan Company, LimitedInventor: Takashi Suzuki
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Patent number: 4876889Abstract: The water vapor content for air in drier ducts, ovens, furnaces and the like is determined by a measurement of sound speed which is done by measuring the time difference between sound pulses reflected by two reflectors spaced a known distance apart in a guide tube. The transmitter-receiver is located at one end of the tube. The tube has enough number of holes to allow the hot moist air to get into the probe tube. A non-porous tube containing dry air placed in the same duct provides a similar measurement of dry-sound speed. The ratio of the two speeds of sound or the two measured time intervals is a simple function of the water vapor content practically independent of temperature thereby providing a very accurate measurement of water vapor content over an extremely wide range of temperatures. The sensor is accurate, immune to harsh environments, has an extremely low time constant, has absolutely no hysteresis and needs no calibration.Type: GrantFiled: July 5, 1988Date of Patent: October 31, 1989Inventors: Parthasarathy Shakkottai, Eug Y. Kwack, Shakkottai P. Venkate-Shan
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Patent number: 4863280Abstract: Integral temperature measurement in electrical machines, transformers and energy conversion systems. An integral temperature measurement for electrical machines, transformers and energy conversion systems produces no additonal potential or voltage in the windings of such equipment. As a result, no conductive or semiconductive material can be used in a temperature sensor. The present invention utilizes the temperature dependency of the propagation conditions of sound or ultrasound in gases and also makes use of light waveguide technology. The sound or ultrasound is guided in a flexible capillary along a path along which an integral temperature measurement is to be taken.Type: GrantFiled: May 12, 1988Date of Patent: September 5, 1989Assignee: Siemens AktiengesellschaftInventor: Guenter Doemens
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Patent number: 4848924Abstract: An apparatus and method for measuring high temperatures in a boiler transmits pulses of acoustic waves, from one side wall of the boiler to an opposite side wall thereof. Acoustic noise within the boiler, as well as the transmitted pulses of acoustic waves are received at the opposite side of the boiler. The received signal is digitized and compared to a digitized sample of the pulses during a time period which is more than the maximum transit time for the pulses between the side walls. A point of maximum correlation between the sample and the signal is taken as the arrival time for the pulse and is used to calculate the transit time of the pulse across the boiler. This transit time is used in turn to calculate the velocity of the pulses. The temperature can then be calculated as a function of the velocity, the molecular weight of the medium and the specific heat ratio of the medium. Each pulse has a modulated frequency between 500 and 3,000 Hz.Type: GrantFiled: August 19, 1987Date of Patent: July 18, 1989Assignee: The Babcock & Wilcox CompanyInventors: Steven P. Nuspl, Edmund P. Szmania, John A. Kleppe, Peter R. Norton
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Patent number: 4816634Abstract: A method and apparatus for measuring strong microwave electric field strengths is disclosed. The apparatus includes a first active temperature probe in cooperation with susceptor means for measuring a temperature indicative of the heating effects of microwave radiation at a test location, and an ambient temperature probe for measuring ambient temperature. The temperature differential between the two probes is used by calibration means for determining electric field strength at the test location. The method includes the steps of heating a susceptor means with microwave radiation, and measuring a temperature indicative of the heating effects of microwave radiation at the test location. Ambient temperature is measured, and the temperature differential used to determine the magnitude of the electric field strength.Type: GrantFiled: October 23, 1987Date of Patent: March 28, 1989Inventors: Ronald R. Lentz, Dan J. Wendt, Jonathon D. Kemske, Peter S. Pesheck
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Patent number: 4772131Abstract: Improvements in electronic apparatus connected with operation of ultrasonic thermometers consisting of an initiating electrical pulse generator which permits selection of the repetition rate at which the ultrasonic thermometer is to be operated, and, to avoid electrical interference caused by power switching, selective commencement of the initiating electrical pulse relative to the power line. Electronic amplifying and transmitting circuitry receiving the reflected information signal pulses from the ultrasonic thermometer amplify the pulses for transmission to pulse processing circuits remotely located from the furnace, assuring that sufficient signal amplitude is received by means of a returned automatic gain control signal to the amplifying and transmitting circuitry.Type: GrantFiled: March 30, 1987Date of Patent: September 20, 1988Assignee: Thermosonics, Inc.Inventors: David W. Varela, Thomas M. Kerley, Andrew R. Gariepy
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Patent number: 4676663Abstract: The invention relates to an arrangement for remote ultrasonic temperature measurement. The arrangement employs a sensor, which in turn comprises an electromechanical transducer, a sensing element, and a hollow ultrasonic waveguide for coupling the sensing element to the transducer. The transducer is designed to propagate surface waves of a torsional or a radial shear mode upon the internal surface of the waveguide. The walls of the waveguide are made sufficiently thick, such that supporting clamps applied to the exterior of the waveguide have no adverse affect on interior wave propagation. The sensing element may be of either a hollow construction using internal surface wave propagation for protection of the active interior surface of the sensing element or of a solid construction in which the active outer surface of the sensing element may be exposed to the environment.Type: GrantFiled: June 17, 1986Date of Patent: June 30, 1987Assignee: General Electric CompanyInventor: Stephen W. Tehon
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Patent number: 4655992Abstract: Temperature, or temperature noise, is measured by employing an ultrasonic beam which strikes at least one pair of points (10A, 10B) which are a known distance apart and the time interval between the two points is resolved and related to the distance to give a measure of temperature of the medium between the two points. The point pairs may be naturally occurring, such as the diametrically opposed edges of a fuel element channel in a sodium-cooled nuclear reactor, or specifically provided. The beam may be at glancing incidence on a number of point pairs in line and, in this situation, the beam is wider in the direction transverse to its path than it is along its path.Type: GrantFiled: January 24, 1985Date of Patent: April 7, 1987Assignee: United Kingdom Atomic Energy AuthorityInventors: James A. McKnight, Iain D. Macleod, Eric J. Burton
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Patent number: 4655608Abstract: A novel laser beam deflection system and method for temperature measurement of combustion flames of known composition is described which comprises a thin wire for placement at a predetermined location within the flame; a pulsed laser source for directing a pulsed beam onto the wire for heating the wire and immediately surrounding gases of the flame to produce an acoustic pulse in the flame; a pair of probe laser sources for directing parallel probe beams through the flame in predetermined spaced relationship to each other and to the wire, and a pair of detectors and associated electronics for detecting the respective deflections of the probe beams resulting from interactions with the pulse and measuring the time difference between respective deflections of the probe beams to determine the speed of the acoustic pulse through the flame and the temperature of the flame from the speed determination.Type: GrantFiled: October 24, 1985Date of Patent: April 7, 1987Assignee: The United States of America as represented by the Secretary of the Air ForceInventors: Larry P. Goss, Dennis F. Grosjean, Benjamin Sarka, Jr., Sigmund W. Kizirnis, Biswa N. Ganguly
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Patent number: 4650346Abstract: The invention relates to an arrangement for ultrasonic temperature measurement. The arrangement combines an ultrasonic temperature sensor and an electronic operating circuit. The ultrasonic temperature sensor comprises an acoustic waveguide, a second acoustic wave propagating resonant element, which is exposed to the thermal conditions under measurement, and whose resonant frequency becomes an indication of the temperature, and decoupling means inserted between the waveguide and the resonant element to facilitate high "Q" operation of the sensor. The arrangement utilizes torsional waves if a solid waveguide is employed, or internal surface waves with axial symmetry if a hollow waveguide is employed. The sensor is excited by a pulsed CW source, whose carrier is retuned to the resonant frequency of the sensor, and measured as the indication of temperature. The electronic operating circuitry achieves improved accuracy in temperature measurement as the "Q" of the sensor increases.Type: GrantFiled: May 23, 1984Date of Patent: March 17, 1987Assignee: General Electric CompanyInventor: Stephen W. Tehon
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Patent number: 4610551Abstract: An ultrasonic temperature sensor is based upon the variation in the speed of propagation of a torsional wave in a material whose torsional modulus varies as a function of temperature. A transducer for producing a torsional wave is coupled through an acoustic waveguide to a sensor element which has a torsional modulus which varies with temperature. A discontinuity in the sensor causes a portion of the torsional wave to be reflected while the remainder traverses the sensor and is reflected. The time delay between the first and second pulses is thus a measure of the temperature.Type: GrantFiled: July 1, 1985Date of Patent: September 9, 1986Assignee: General Electric Co.Inventor: Kirti C. Shah
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Patent number: 4541732Abstract: An ultrasonic temperature sensor is based upon the variation in the speed of propagation of a torsional wave in a material whose torsional modulus varies as a function of temperature. A transducer for producing a torsional wave is coupled through an accoustic waveguide to a sensor element which has a torsional modulus which varies with temperature. A discontinuity in the sensor causes a portion of the torsional wave to be reflected while the remainder traverses the sensor and is reflected. The time delay between the first and second pulses is thus a measure of the temperature.Type: GrantFiled: January 27, 1984Date of Patent: September 17, 1985Assignee: General Electric Co.Inventor: Kirti C. Shah
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Patent number: 4513749Abstract: Two coaxial acoustic beams, one focused and the other unfocused, are used to measure changes in temperature within a localized region in a body. The focal region of the focused beam is located at the area to be measured. Changes in the relative phase angle between the two beams are indicative of changes in acoustic properties occurring at the focal region. Since the two beams have generally the same propagation path outside of the focal region, they will be similarly affected by acoustic variations which occur there, so there will not be any relative phase change between them due to such variations.Type: GrantFiled: November 18, 1982Date of Patent: April 30, 1985Assignee: Board of Trustees of Leland Stanford UniversityInventors: Gordon S. Kino, Simon D. Bennett, Didier Husson