Density Or Specific Gravity Of Gas Patents (Class 73/24.05)
  • Patent number: 10466087
    Abstract: A method for calculating a fluid parameter of a fluid flowing through a vibratory flow meter is provided. The method comprises vibrating the flow meter at one or more frequencies and receiving a vibrational response. The method further comprises generating a first fluid property and generating at least a second fluid property. The method further comprises calculating a fluid parameter based on the first fluid property and the at least second fluid property.
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: November 5, 2019
    Assignee: Micron Motion, Inc.
    Inventors: Joel Weinstein, Mark James Bell, Andrew Timothy Patten
  • Patent number: 10175212
    Abstract: A gas analysis system includes a fluidic channel for flow of a gas to be analyzed, a detector in the channel and adapted for measuring interactions of the gas with the detector, the detector including a resonator of the electromechanical nanosystem (NEMS) type and a heating system for heating a part of the detector, an actuation device for vibrationally actuating the resonator according to an excitation signal applied to an input of the detector, a detection device adapted for providing an output electric signal representative of the vibrations of the resonator, a read-out device connected to an input of the detector and configured for simultaneously measuring, from the output signal of the detector, the change in resonance frequency and the change in amplitude of the vibrations at the resonance frequency of the resonator, and a processing device configured for determining from the changes a fluidic characteristic of the gas.
    Type: Grant
    Filed: December 2, 2014
    Date of Patent: January 8, 2019
    Inventors: Philippe Andreucci, Eric Colinet, Laurent Duraffourg, Edward Myers, Mélanie Petitjean, Mickael Lee Roukes, Joshua Whiting
  • Patent number: 10060841
    Abstract: A fluid densitometer for measuring the density of fluid includes an inner tube and outer tube. A sensor assembly passes through the outer tube to contact an outer radial surface of the inner tube. The inner tube is vibrated at a predetermined frequency, and detected resonance signals are used to determine fluid density.
    Type: Grant
    Filed: August 15, 2016
    Date of Patent: August 28, 2018
    Inventors: Joel David Bell, Randall W. Dear, David A. Tinker
  • Patent number: 10018034
    Abstract: A system, method and apparatus for determining a parameter of a fluid is disclosed. Measurements are obtained of a temperature of the fluid and a pressure of the fluid. A material is disposed in the fluid, and an actuator applies a stimulation pulse at a selected frequency to the material to generate an oscillation in the material. A measurement device measures a parameter of oscillation of the material in response to the stimulation pulse, the parameter of oscillation being affected by the fluid in which the material is disposed. A processor determines the parameter of the fluid from the measured parameter of the oscillation, the temperature measurement and the pressure measurement.
    Type: Grant
    Filed: March 10, 2014
    Date of Patent: July 10, 2018
    Inventor: Vernon Chronister
  • Patent number: 9804126
    Abstract: An acoustical transformer having a last matching section that includes a protective barrier of low permeability. The protective barrier is in contact with a test medium. In one embodiment, the protective barrier comprises one or more low permeability layers, such as a metallic foil or metallic coating(s) disposed on a low impedance layer such as polyimide, so that the low impedance layer and the protective barrier constitute the last matching section of the acoustical transformer. In other embodiments, the protective barrier comprises a fluoropolymer. A method for determining the thicknesses of the various layers of the acoustical transformer for enhanced performance is also disclosed.
    Type: Grant
    Filed: December 5, 2012
    Date of Patent: October 31, 2017
    Assignee: Veeco Instruments Inc.
    Inventors: Raymond C. Logue, Don N. Sirota, William E. Quinn, Owan C. Watkins, Maria D. Ferreira, Wei Zhang
  • Patent number: 9423331
    Abstract: A method of determining energy content using a specific gravity meter double calibrated to measure both molecular weight and relative density.
    Type: Grant
    Filed: April 13, 2011
    Date of Patent: August 23, 2016
    Assignee: Mobrey Limited
    Inventor: Simon Patrick Hunter Wheeler
  • Patent number: 9255870
    Abstract: There is provided a method of, and apparatus for, measuring the mass of a gas under pressure using a piezoelectric oscillator. The gas is contained within a pressure vessel (100) having a fixed internal volume (V) and the piezoelectric oscillator (202) is immersed in the gas within the pressure vessel (100). The method comprises: a) utilizing said piezoelectric oscillator (202) to measure the density of the gas within the high-pressure vessel (100); b) determining, from the density measurement and from the internal volume (V) of said pressure vessel, the mass of the gas within the pressure vessel (100). By providing such a method, the true contents (i.e. mass) of fluid in a pressure vessel such as a cylinder can be measured directly without the need to compensate for factors such as temperature or compressibility. This allows a determination of mass through direct derivation from the density of the gas in the cylinder, reducing the need for additional sensors or complex calculations to be performed.
    Type: Grant
    Filed: November 28, 2011
    Date of Patent: February 9, 2016
    Inventors: Neil Alexander Downie, Marcel Behrens, Lateef Olusegun Adigun Obadun
  • Patent number: 9228930
    Abstract: An apparatus that is able to measure a viscosity and a density directly within a short time with a small amount of sample, which has been difficult for existing vibratory viscometer. The end part of an oscillator is formed in a shape, such as a sphere, whose resistance by a fluid can be logically derived, and the viscosity and the density of a fluid are calculated based on a predefined mechanical impedance and on an amplitude ratio and a phase difference of accelerations in the cases the oscillator is in the air and is in the fluid.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: January 5, 2016
    Assignee: RION Co., Ltd.
    Inventors: Junichi Motoyoshi, Takashi Iwakura
  • Patent number: 9075942
    Abstract: A system is provided. The system comprises a computer system comprising at least one processor, a thermodynamic state solver application, and a thermodynamic system solver application. When executed by the at least one processor, the thermodynamic state solver application computes a flash equilibrium state solution for each of a plurality of nodes in a thermodynamic network and determines for each of the plurality of nodes at least one sensitivity of a first thermodynamic property with reference to at least one second thermodynamic property. When executed by the at least one processor, the thermodynamic system solver computes a pressure at each of the nodes and flows between the nodes based at least in part on the sensitivities, wherein a result based on the pressures and flows is determined.
    Type: Grant
    Filed: October 30, 2013
    Date of Patent: July 7, 2015
    Assignee: Invensys Systems, Inc.
    Inventor: Ian H. Boys
  • Publication number: 20140060154
    Abstract: A method for producing at least one oscillation measurement signal, which has vibrations of a vibratory body are registered. A temperature sensor is applied thermally attached with a non fluid contacting, second surface of the vibratory body for producing a temperature measurement signal representing a time curve of a variable temperature of the vibratory body. The temperature measurement signal can follow, however time delayed, a change of the temperature of the vibratory body from a beginning temperature value, to a new temperature value. Based on the oscillation measurement signal as well as the temperature measurement signal, density, measured values are produced representing the density, wherein, during such, discrepancies possibly occurring between the time curve of the temperature of the vibratory body and the temperature measurement signal are taken into consideration, respectively at least partially compensated.
    Type: Application
    Filed: December 17, 2012
    Publication date: March 6, 2014
    Applicant: Endress + Hauser FLowtec AG
    Inventors: Coen Van Dijk, Omar Momente, Heinerich Hagenmeyer
  • Patent number: 8548755
    Abstract: Switching a transmitting and receiving direction of two transducers (2,3) in the forward and the reverse direction, a time differential memory part (17b) storing a propagation time differential every K times a unit measurement process being executed, the propagation time differential being a differential between a propagation time of the ultrasonic wave signal in a forward direction and in a reverse direction, a flow rate calculating part (15) calculating a flow rate of a passing fluid based on a lump sum of propagation times in both the forward and the reverse directions obtained at least every K times of a unit measurement process being executed, an estimating part (18) estimating a change in a momentary flow rate of the fluid based on the time differential obtained every K times of the unit measurement process being executed and storing thereof in a time differential memory part (17b), thus obtaining an accurate flow rate and detecting the change in the momentary flow rate.
    Type: Grant
    Filed: December 25, 2009
    Date of Patent: October 1, 2013
    Assignee: Panasonic Corporation
    Inventors: Koichi Takemura, Fumikazu Shiba, Daisuke Bessho
  • Patent number: 7735353
    Abstract: A method and apparatus for imparting oscillatory motion on a test sample is disclosed in which oscillators, preferably in tubular form, are surrounded by housings. An actuator causes deforming of the housings, and the deforming movement is linked to the oscillators.
    Type: Grant
    Filed: June 20, 2006
    Date of Patent: June 15, 2010
    Assignee: Rudolph Research Analytical
    Inventor: Jeff Wagner
  • Patent number: 7730766
    Abstract: A gas viscosity sensor comprises a signal processing circuit and a sensor element, including a gas pressure generating system and a differential pressure measuring system in fluid communication therewith, the differential pressure measuring system comprising a measuring chamber (14) bounded by a thin membrane (28), an inlet-outlet channel or orifice interconnecting the measuring chamber to a source of gas for which the viscosity is to be determined, the inlet-outlet channel or orifice having dimensions adapted to provide resistance to the outflow and inflow of gas in the measuring chamber, and a membrane displacement sensor (32) adapted to measure a time dependent displacement of the membrane due to pressure variations in the measuring cavity.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: June 8, 2010
    Assignee: Ecole Polytechnique Federale de Lausanne
    Inventors: Peter Ryser, Sigfrid Straessler
  • Patent number: 7476851
    Abstract: Guidelines for designing lenses or systems for aerodynamic focusing of nanoparticle or cluster beams. The design process may involve obtaining a relationship between particle size, operating pressure and aperture size, and selecting the operating pressure to provide continuum flow of an aerosol beam through the aerodynamic lens. Particles having diameters less than 30 nanometer may be focused. Simulation techniques for evaluating designed lenses are also disclosed.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: January 13, 2009
    Assignee: Regents of the University of Minnesota
    Inventors: Xiaoliang Wang, Peter H. McMurry, Einar Kruis
  • Patent number: 7395711
    Abstract: A system for determining property of multiphase fluids based on ultrasonic diffraction grating spectroscopy includes a diffraction grating on a solid in contact with the fluid. An interrogation device delivers ultrasound through the solid and a captures a reflection spectrum from the diffraction grating. The reflection spectrum exhibits peaks whose relative size depends on the properties of the various phases of the multiphase fluid. For example, for particles in a liquid, the peaks exhibit dependence on the particle size and the particle volume fraction. Where the exact relationship is know know a priori, data from different peaks of the same reflection spectrum or data from the peaks of different spectra obtained from different diffraction gratings can be used to resolve the size and volume fraction.
    Type: Grant
    Filed: January 19, 2005
    Date of Patent: July 8, 2008
    Assignee: Battelle Memorial Institute
    Inventor: Margaret S. Greenwood
  • Patent number: 7316151
    Abstract: An apparatus for BTU measurement of natural gas having at least one reference spherical acoustic resonator containing a reference gas, a sample gas spherical acoustic resonator containing a natural gas sample, a first acoustic transmitter adapted to transmit a first acoustic signal into the natural gas sample, a second acoustic transmitter adapted to transmit a second acoustic signal into the reference gas, a first acoustic receiver adapted to receive at least a portion of the first acoustic signal, and a second acoustic receiver adapted to receive at least a portion of the second acoustic signal. Using the third radial resonance frequencies for the sample gas and reference gas, a data processor operably connected with a signal output of the first acoustic receiver determines the specific gravity of the natural gas sample. The discovered linear relationship between specific gravity and heating value of natural gas enables a determination of the heating value from the measured specific gravity.
    Type: Grant
    Filed: April 26, 2006
    Date of Patent: January 8, 2008
    Assignee: Gas Technology Institute
    Inventor: Alwarappa Sivaraman
  • Publication number: 20070220976
    Abstract: A method for measuring operational density and/or operational sound velocity in a gaseous medium uses a sound transducer that is capable of vibrating, which is disposed in a housing in such a manner that chambers having the same volume are formed on both sides of the sound transducer, which are filled by the gaseous medium. The chambers are connected with one another by way of an open channel having defined dimensions. Using an exciter vibration applied to the sound transducer, the impedance of the sound transducer, which is influenced by the density of the gaseous medium, is determined within a frequency range that can be established, as a function of the exciter frequency. From this, the operational density and/or the operational sound velocity of the gaseous medium are determined using a plurality of characteristic frequencies of the sound transducer vibrating in the gaseous medium.
    Type: Application
    Filed: March 21, 2007
    Publication date: September 27, 2007
    Inventor: Ulrich Ewerlin
  • Patent number: 7191638
    Abstract: A device for determining and/or monitoring at least one physical parameter of a medium, having at least one mechanically oscillatable unit and at least one drive-/receive unit. The drive-/receive unit excites the oscillatable unit to oscillate, or, it receives the oscillations of the oscillatable unit, as the case may be. The invention includes that in the drive-/receive unit at least one piezo-drive is provided, which has at least one exterior surface. The exterior surface is composed of at least two segments of different polarization, wherein the directions of polarization are directed essentially opposite to one another. The mechanically oscillatable unit is directly or indirectly connected with the exterior surface, so that the mechanically oscillatable unit is excited to a movement, or so that the movement of the mechanically oscillatable unit is received. The movement always has at least two different force components.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: March 20, 2007
    Assignee: Endress + Hauser GmbH + Co. KG
    Inventor: Sergej Lopatin
  • Patent number: 7082810
    Abstract: A gas sensor (10) including a measurement chamber (28) into which a gas GS is flown and a detection element main body (40) facing the measurement chamber (28). The detection element main body (40) includes an element case 42, and a protective film (48) is adhered to a bottom surface thereof. An acoustic matching plate (50) and a piezoelectric element (51) of a substantially columnar shape and a tube body (52) provided in a position surrounding the acoustic matching plate 50 and the piezoelectric element 51 are housed in the element case (42). A filler is then introduced into the element case (42), whereby the acoustic matching plate (50), the piezoelectric element (51), and the tube body (52) are sealed by a filled layer (99).
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: August 1, 2006
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masashi Sakamoto, Yoshikuni Sato, Keigo Banno, Katsuya Otake, Takeshi Morita, Hideki Ishikawa, Noboru Ishida
  • Patent number: 7081745
    Abstract: A paramagnetic oxygen sensor and method employs a pressure sensor having a membrane extending through an air gap for a magnetic field. A piezoelectric element is mounted on the membrane. Gas chambers are formed on either side of the membrane. The gas mixture, the properties of which are to be measured, is supplied to one of the chambers. A reference gas is applied to the other chamber. A pulsating magnetic field is provided across the air gap and through the chambers containing the gas mixture and reference gas. The differing responses of the gas mixture and reference gas to the magnetic field deflect the membrane. The deflection of the membrane is sensed by the piezoelectric element. The piezoelectric element maybe operated either in a passive mode or active mode to sense the deflection of the membrane.
    Type: Grant
    Filed: March 14, 2003
    Date of Patent: July 25, 2006
    Assignee: GE Healthcare Finland Oy
    Inventor: Heikki Haveri
  • Patent number: 7059171
    Abstract: The density of at least one fluid in a pipe 12 is determined using a pair of effective sound speeds a1eff and a2eff of the fluid/pipe system. The pair of effective system sound speed measurements are taken at two sensing regions X1, X2 along the pipe wherein each of the sensing regions comprises a different system cross sectional compliance. The pair of effective system sound speeds a1eff and a2eff are provided to signal processing logic 60, which determines the density of the fluid 13 flowing in the pipe 12. The effective system sound speeds a1eff and a2eff may be provided by a pair of sound speed meters positioned at sensing regions X1, X2 wherein the sound speed meters utilize a spatial array of acoustic pressure sensors placed at predetermined axial locations along the pipe 12. The acoustic pressure sensors provide acoustic pressure signals which are utilized to determine the effective system speed of sound a1eff and a2eff of the fluid (or mixture)/pipe system.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: June 13, 2006
    Assignee: Weatherford/Lamb, Inc.
    Inventor: Daniel L. Gysling
  • Patent number: 6971259
    Abstract: The density of at least one fluid in a pipe is determined using a pair of effective sound speeds a1eff and a2eff of the fluid/pipe system. The pair of effective sound speed measurements is taken at two sensing regions along the pipe wherein each of the sensing regions has a different cross sectional area compliance. The pair of effective sound speeds a1eff and a2eff is provided to signal processing logic 60, which determines the density of the fluid flowing in the pipe. The effective sound speeds a1eff and a2eff may be provided by a pair of sound speed meters positioned at the sensing regions wherein the sound speed meters utilize a spatial array of acoustic pressure sensors placed at predetermined axial locations along the pipe. The acoustic pressure sensors measure one-dimensional planar acoustic waves that are lower in frequency (and longer wavelength) signals than those used for ultrasonic flow meters, and thus is more tolerant to inhomogeneities in the flow.
    Type: Grant
    Filed: November 7, 2001
    Date of Patent: December 6, 2005
    Assignee: Weatherford/Lamb, Inc.
    Inventor: Daniel L. Gysling
  • Patent number: 6877375
    Abstract: A system for determining a property of a fluid based on ultrasonic diffraction grating spectroscopy includes a diffraction grating on a solid in contact with the fluid. An interrogation device delivers ultrasound through the solid and a captures a reflection spectrum from the diffraction grating. The reflection spectrum including a diffraction order equal to zero exhibits a peak whose location is used to determine speed of sound in the fluid. A separate measurement of the acoustic impedance is combined with the determined speed of sound to yield a measure of fluid density. A system for determining acoustic impedance includes an ultrasonic transducer on a first surface of a solid member, and an opposed second surface of the member is in contact with a fluid to be monitored. A longitudinal ultrasonic pulse is delivered through the solid member, and a multiplicity of pulse echoes caused by reflections of the ultrasonic pulse between the solid-fluid interface and the transducer-solid interface are detected.
    Type: Grant
    Filed: May 6, 2003
    Date of Patent: April 12, 2005
    Assignee: Battelle Memorial Institute
    Inventor: Margaret S. Greenwood
  • Publication number: 20040129056
    Abstract: A sensor for monitoring gas content. The sensor comprises a housing defining at least two cavities and a resonating structure positioned in each of the cavities. Each of the resonating structures has a resonant frequency dependent upon a physical characteristic of a gas in its respective cavity. Means for exciting the resonating structures generates output signals therefrom, and means compares the output signals from each of the resonating structures and outputs a comparison signal indicative of a difference between the resonant frequencies of the two structures and the relative gas content of the at least two cavities.
    Type: Application
    Filed: November 5, 2003
    Publication date: July 8, 2004
    Inventors: Bertil Hok, Ralph Bernstein, Per Gloersen
  • Patent number: 6715339
    Abstract: An apparatus to normalize a flow rate of a fluid in a main flow channel is provided. The apparatus uses a movable member, such as a flexible membrane disposed for reciprocating displacement, to produce a constant dither flow of the fluid that is independent of fluid composition. This dither flow generates a signal output from a normalizing flow sensor that both represents a characteristic property of the fluid and a flow rate calibration factor. A similar apparatus to determine the characteristic property or flow rate calibration factor is also provided. The devices disclosed may be used in numerous industrial, process, and medical flow system applications for normalization of flow sensors and to derive other properties of a fluid.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: April 6, 2004
    Assignee: Honeywell International Inc.
    Inventors: Ulrich Bonne, David Kubisiak
  • Patent number: 6704660
    Abstract: A method to determine thermodynamic properties of a natural gas hydrocarbon, when the speed of sound in the gas is known at an arbitrary temperature and pressure. Thus, the known parameters are the sound speed, temperature, pressure, and concentrations of any dilute components of the gas. The method uses a set of reference gases and their calculated density and speed of sound values to estimate the density of the subject gas. Additional calculations can be made to estimate the molecular weight of the subject gas, which can then be used as the basis for mass flow calculations, to determine the speed of sound at standard pressure and temperature, and to determine various thermophysical characteristics of the gas.
    Type: Grant
    Filed: September 9, 2002
    Date of Patent: March 9, 2004
    Assignee: Southwest Research Institute
    Inventors: Thomas E. Morrow, Kendricks A. Behring, II
  • Publication number: 20040003649
    Abstract: A programmable device for analyzing mixtures of suspended vapors and air by pinging particles making up the vapors at their mechanical resonant frequencies and detecting the resultant rings.
    Type: Application
    Filed: June 26, 2003
    Publication date: January 8, 2004
    Inventor: Robert W. Beckwith
  • Patent number: 6543274
    Abstract: A sensor arrangement for ascertaining the density and the viscosity of a liquid is proposed, having an arrangement comprising at least two basic sensor elements, at least one of which can be wetted with the liquid, and having electro-acoustical transducers (6) in the basic sensor elements for generating and detecting surface acoustic waves with predetermined wave modes, from whose propagation behavior along a measurement path a measure for the density and the viscosity of the liquid can be ascertained. Liquid traps (17) for the liquid, which extend in the applicable measurement path, are disposed in the region of at least one of the basic sensor elements, parallel to the direction of propagation of the surface acoustic wave.
    Type: Grant
    Filed: April 27, 2001
    Date of Patent: April 8, 2003
    Assignee: Robert Bosch GmbH
    Inventors: Falk Herrmann, Dietmar Hahn, Gottfried Flik
  • Patent number: 6494079
    Abstract: A method and apparatus for measuring properties of a fluid composition in a conduit includes a mechanical resonator connected to a measurement circuit. The measurement circuit provides a variable frequency input signal to the mechanical resonator, causing the mechanical resonator to oscillate. The input signal is then sent to the mechanical resonator and swept over a selected frequency range. The mechanical resonator's response over the frequency range depends on various characteristics of the fluid being tested, such as the temperature, viscosity, and other physical properties.
    Type: Grant
    Filed: March 7, 2001
    Date of Patent: December 17, 2002
    Assignee: Symyx Technologies, Inc.
    Inventors: Leonid Matsiev, James Bennett, Eric McFarland
  • Patent number: 6474137
    Abstract: A method and apparatus for measuring the relative density of a gas, for example natural gas. The gas is supplied through an inlet to a chamber and is output through an outlet. Using a control and an ultra-sonic transducer emitter and an ultra-sonic transducer receiver, the speed of sound in the gas corrected to standard conditions is calculated. Then, the control operates to measure the relative density RD of the gas using the formula RD=a×SoSsc+b, where SoSsc is the speed of sound in the gas corrected to standard conditions, and a and b are constants.
    Type: Grant
    Filed: February 3, 2000
    Date of Patent: November 5, 2002
    Assignee: Lattice Intellectual Property Limited
    Inventors: Paul Stephen Hammond, Robert Richard Thurston
  • Patent number: 6321588
    Abstract: A device for detecting chemical substances includes a plurality of sensors arranged in an array. The sensors are connected to respective oscillator circuits which drive the sensors, and the oscillator circuits are coupled to a power multiplexer which provides the circuits with power according to a timing pattern such that not all of the oscillator circuits are activated at any one time. Preferably, only one oscillator circuit is activated at any given time. This multiplexing arrangement saves power and substantially eliminates cross talk between the oscillator circuits. The oscillator circuits are preferably application specific integrated circuits (ASICs), and the sensors are preferably surface acoustic wave (SAW) devices. In use, the SAW sensors are exposed to a gas, such as air, containing the chemical substance to be detected. Signals from the SAW sensors are analyzed to identify the chemical substance.
    Type: Grant
    Filed: September 11, 1998
    Date of Patent: November 27, 2001
    Assignee: Femtometrics, Inc.
    Inventors: William D. Bowers, Frank Bahrami, John Tran
  • Patent number: 6311549
    Abstract: A method and apparatus for measuring the viscosity and/or specific density of a fluid utilizes a microcantilever vibrated in the analyte fluid. The source of vibration is switched on and off and the transient behavior or decay in amplitude of the vibration is monitored. The method is particularly useful for the measurement of process conditions in remote locations in real time.
    Type: Grant
    Filed: September 23, 1999
    Date of Patent: November 6, 2001
    Assignee: U T Battelle LLC
    Inventors: Thomas G. Thundat, Patrick I. Oden, Robert J. Warmack, Eric Laurent Finot
  • Patent number: 6286361
    Abstract: An apparatus for detecting pressure in a hollow fan blade of a turbofan gas turbine engine comprises a magnetostriction transducer arranged in a sub chamber of the fan blade which is interconnected to a main chamber. A magnetic coil is arranged in the fan casing of the turbofan remote from the fan blade, and an alternating current is supplied from a supply to the magnetic coil to produce an alternating magnetic field. The alternating magnetic field causes the magnetostriction transducer to generate vibrations in the fan blade and the magnetostriction transducer. A magnetic search coil detects changes in the magnetic field, which corresponds to the vibrations, and a processor analyses the vibrations to determine if there has been a change in the resonant frequency of the vibrations which is indicative of a change in the pressure in the fan blade. The processor supplies a signal to a display or to an alarm. The change in the pressure is indicative that the fan blade is cracked and needs replacing.
    Type: Grant
    Filed: January 5, 1998
    Date of Patent: September 11, 2001
    Assignee: Rolls-Royce plc
    Inventors: Alan R Jones, John R Webster, Ian D Brown, Duncan Pollard, Rodney D Greenough
  • Patent number: 6279378
    Abstract: An ultrasonic gas analyzer includes an acoustic cavity through which an air sample is drawn by a low speed air pump or other mechanism. The cavity has a pair of ultrasonic wave transmitters/receivers on opposite sides of the acoustic cavity. An electronic circuit controls the transmitters/receivers so that a high frequency ultrasonic wave is propagated across the cavity and thereby through the gas flowing through the cavity. This ultrasonic wave reflects back and forward across the acoustic cavity and the transmitters/receivers receive this wave and supply a signal indicative of the wave to an electronic circuit. Based on the time of flight data for the ultrasonic wave being reflected in a gas/air mixture and in air and the amplitude of those reflected ultrasonic waves, a determination is made as to the gases within the gas/air mixture. This determination then can be displayed and an audio signal can be generated depending on the amount of detected gases.
    Type: Grant
    Filed: October 27, 1999
    Date of Patent: August 28, 2001
    Assignee: The University of Chicago
    Inventors: Shuh-Haw Sheen, Hual-Te Chien, Apostolos C. Raptis
  • Patent number: 6269686
    Abstract: A sensor which has a bending reed and a piezoelectric resonator. Due to excitation by the piezoelectric resonator, the bending reed can be excited to vibration in a measurable medium. In this context, the vibration frequency and the damping of the bending reed are a function of the density and the viscosity, respectively, of the measurable medium. This can be measured by a piezoresistive element, and thus the density and viscosity of the measurable medium are ascertained.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: August 7, 2001
    Assignee: Robert Bosch GmbH
    Inventors: Dietmar Hahn, Gottfried Flik, Falk Herrmann
  • Patent number: 6250132
    Abstract: A modular apparatus for analyzing a fluid includes a disposable fluidic sensor module, a replaceable transducer module, and an expendable electronics package. The disposable fluidic sensor includes a fluidic flowmeter and a capillary structure formed in a plate-like member which receives a sample fluid flow. The fluidic flowmeter is responsive to the fluid flow to generate an output indicative of the flow rate of the fluid, and the capillary structure restricts the fluid flow such that a pressure drop across the capillary structure is related to the viscosity of the fluid. The fluidic flowmeter can be a fluidic oscillator whose oscillation frequency is related to the fluid flow rate. The oscillator flowmeter also serves as an orifice, with the pressure drop across the oscillator being related to the density of the fluid.
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: June 26, 2001
    Assignee: metaSENSORS, Inc.
    Inventor: Tadeusz M. Drzewiecki
  • Patent number: 6209387
    Abstract: Disclosed is a system and method for determining the thermodynamic properties and percentage of each component of a multi-component gas medium by using speed of sound in conjunction with other data. The present system comprises a computer system with means for obtaining the temperature, pressure, and speed of sound of a gas medium. The computer system operates according to operating logic stored in memory. According to the operating logic, measurements of the temperature, pressure, speed of sound and acoustic impedance are recorded in a gas pipe or other transport device to determine a convergent temperature range. Next a convergent series is extrapolated from the convergent temperature range and a convergent series calculation using isochoric convergence iterations is performed to obtain estimates of the thermo-physical properties of the gas medium.
    Type: Grant
    Filed: June 29, 1999
    Date of Patent: April 3, 2001
    Assignee: Gas Research Institute
    Inventor: Jeffrey L. Savidge