Abstract: In industrial sensing applications at least one parameter of at least one fluid in a pipe 12 is measured using a spatial array of acoustic pressure sensors 14,16,18 placed at predetermined axial locations x1, x2, x3 along the pipe 12. The pressure sensors 14,16,18 provide acoustic pressure signals P1(t), P2(t), P3(t) on lines 20,22,24 which are provided to signal processing logic 60 which determines the speed of sound amix of the fluid (or mixture) in the pipe 12 using acoustic spatial array signal processing techniques with the direction of propagation of the acoustic signals along the longitudinal axis of the pipe 12. Numerous spatial array-processing techniques may be employed to determine the speed of sound amix. The speed of sound amix is provided to logic 48, which calculates the percent composition of the mixture, e.g., water fraction, or any other parameter of the mixture, or fluid, which is related to the sound speed amix. The logic 60 may also determine the Mach number Mx of the fluid.

Abstract: PURPOSE: To provide the biosolution sensor enabling a high accuracy and a small size with an SH-SAW device.

Abstract: A method and an apparatus for characterizing the barrier properties of an array of coatings. The method including providing a plurality of acoustic wave devices, wherein each of the plurality of acoustic wave devices comprises at least one surface, and providing a plurality of coating materials suitable for forming a plurality of coatings on the at least one surface of each of the plurality of acoustic wave devices. The method also including coating each of the plurality of acoustic wave devices with at least one of the plurality of coating materials to form a plurality of coated acoustic wave devices and measuring a predetermined output parameter of each of the plurality of coated acoustic wave devices.

Abstract: An analytical apparatus, such as a quartz crystal microbalance, comprising a piezoelectric sensor and an oscillator circuit, coupled to the sensor, to oscillate at a frequency substantially determined by a resonant frequency of the sensor, and to provide an output signal at the oscillator frequency at an output, the oscillator circuit incorporates means to maintain a substantially constant drive signal to the piezoelectric sensor. Preferably the substantially constant drive signal is maintained by AGC means (33) within a feedback loop of the oscillator. Advantageously the gain control signal is used as an indication of the Q of the piezoelectric sensor. It is desirable that the drive signal to the sensor is substantially sinusoidal since this provides greater accuracy, sensitivity and stability for the apparatus. This can be achieved by ensuring that all the elements in the feedback loop providing signal gain and attenuation are configured to operate in a substantially linear mode.

Abstract: A system and technique for determining fluid properties includes an ultrasonic transducer 30 on a first surface 42 of a solid member 40. An opposed second surface 44 of the member 40 is in contact with a fluid 25 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 and processed by a processing apparatus 22. The apparatus 22 determines the decay rate of the detected echo amplitude as a function of echo number and compares this value to a calibrated decay rate to determine an acoustic property of the fluid. The speed of ultrasound in the fluid is also determined and the fluid density is determined as a function of the speed of ultrasound and the determined acoustic property.

Abstract: Systems and methods for ultrasound sensing a compound's concentration in aqueous solution are provided. As a result of the ultrasound sensing, an accurate real time measurement of the concentration of the compound of interest in aqueous solution is obtained. In various non-limiting embodiments, the invention provides ultrasound sensing of methanol's concentration in aqueous solution in connection with a fuel circulation process for a direct methanol fuel cell. Since the speed of sound in a water-methanol system increases significantly with methanol content, techniques for measuring characteristic sound velocities are used to give sufficient resolution for a fuel circulation process.

Abstract: A method and corresponding system for measuring the speed of sound in a fluid contained within an elongated body, the sound transversing the elongated body substantially along a direction aligned with the longest axis of the elongated body, the method including the steps of: providing at predetermined locations an array of at least two sensors distributed along the elongated body, each sensor for discerning and signaling spatio-temporally sampled data including information indicating the pressure of the fluid at the position of the sensor; acquiring the spatio-temporally sampled data from each sensor at each of a number of instants of time; constructing a plot derivable from a plot, using a technique selected from the group consisting of spectral-based algorithms; identifying in the plot a spectral ridge, and determining the slope of the spectral ridge; and determining the speed of sound assuming a relation between the speed of sound and the slope of the spectral ridge.

Abstract: Volume measuring apparatus is used in a closed space as in the case of volume measurement of liquid in a container placed on an orbit of an artificial satellite and permits the volume measurement in a state without mixture with gas, liquid, or solid. A volume measuring apparatus is an apparatus for measuring the volume of liquid or solid under microgravity, which has two or more containers coupled to each other by a pipe, a device for separating or fixing a gas phase, a liquid phase, or a solid phase, a pressure fluctuation source, a pressure signal receiver, a pressure gage, and a thermometer, wherein the separating or fixing device, the pressure fluctuation source, the pressure signal receiver, the pressure gage, and the thermometer are placed in the containers and wherein the pressure fluctuation source, the pressure signal receiver, the pressure gage, and the thermometer are connected to a signal analyzing unit.

Abstract: The present invention relates to a miniature rheometer, a parallel rheometer, and improved force sensor elements which may advantageously be used in combination with the miniature rheometer and the parallel rheometer. The miniature rheometer is adapted to determine rheological characteristics of materials which are provided in the form of small quantity samples. The miniature rheometer comprises an actuating element, a sensing element and a feedback circuit to provide rebalance of the shear force applied by the sample to the sensing element, which insures an exceptional stiffness in determining the shear strain so as to allow measurements of high accuracy. The parallel rheometer of the present invention allows simultaneous measurements of a plurality of samples so as to allow of a plurality of samples within a short time period. The force sensor element according to the present invention allows simultaneous measurement of a shear force and a normal force applied to the sensor element.

Abstract: A cavitation sensor includes an ultrasonically absorbent coating (20) disposed around a piezoelectric element (30) and a conduit (25). The conduit (25) includes a boundary delimited by the piezoelectric element (30), while the ultrasonically absorbent coating (20) is substantially transparent to acoustic driving field frequencies. The sensor is more accurate than prior art sensors.

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.

Abstract: In industrial sensing applications at least one parameter of at least one fluid in a pipe 12 is measured using a spatial array of acoustic pressure sensors 14, 16, 18 placed at predetermined axial locations x1, x2, x3 along the pipe 12. The pressure sensors 14, 16, 18 provide acoustic pressure signals P1(t), P2(t), P3(t) on lines 20, 22, 24 which are provided to signal processing logic 60 which determines the speed of sound amix of the fluid (or mixture) in the pipe 12 using acoustic spatial array signal processing techniques with the direction of propagation of the acoustic signals along the longitudinal axis of the pipe 12. Numerous spatial array-processing techniques may be employed to determine the speed of sound amix. The speed of sound amix is provided to logic 48, which calculates the percent composition of the mixture, e.g., water fraction, or any other parameter of the mixture, or fluid, which is related to the sound speed amix. The logic 60 may also determine the Mach number Mx of the fluid.

Abstract: At least one parameter of at least one fluid in a pipe 12 is measured using a spatial array of acoustic pressure sensors 14,16,18 placed at predetermined axial locations x1,x2,x3 along the pipe 12. The pressure sensors 14,16,18 provide acoustic pressure signals P1(t), P2(t), P3(t) on lines 20,22,24 which are provided to signal processing logic 60 which determines the speed of sound amix of the fluid (or mixture) in the pipe 12 using acoustic spatial array signal processing techniques with the direction of propagation of the acoustic signals along the longitudinal axis of the pipe 12. Numerous spatial array processing techniques may be employed to determined the speed of sound amix. The speed of sound amix is provided to logic 48 which calculates the percent composition of the mixture, e.g., water fraction, or any other parameter of the mixture or fluid which is related to the sound speed amix. The logic 60 may also determine the Mach number Mx of the fluid.

Abstract: An apparatus and related method for measuring the presence or degree of stratified flow in a two-phase flow is disclosed. A first speed of sound for the fluid flowing through the pipeline is measured for an ultrasonic signal that would reflect from stratified flow, if present. A second speed of sound is measured at a location that would not reflect off the stratified flow. A difference in these two measurements indicates the presence of stratified flow. The level of stratified flow can be determined based on the magnitude of the difference. Because this method is so sensitive to changes in the amount of stratified flow, it is more reliable than previously known methods.

Abstract: A fluid filled transformer including a tank for containing at least primary and secondary windings, a radiator connected to the tank via top and bottom headers, a fluid disposed in the tank, a fluid circulation flow path including passages through the windings, radiator, headers, and at least a portion of the tank, and at least one diagnostic sensor disposed within the fluid circulation flow path for measuring properties of the fluid. By positioning the sensor within the circulation flow path, measured values are more reliable, accurate, and efficiently sensed.

Abstract: Methods and apparatus for screening diverse arrays of materials are provided. In one aspect, systems and methods are provided for imaging a library of materials using ultrasonic imaging techniques. In another aspect, systems and methods are provided for generating acoustic waves in a tank filled with a coupling liquid to form a disturbance that is representative of a library of materials. In another aspect of the invention, a mechanical resonator is used to evaluate various properties (e.g., molecular weight, viscosity, specific weight, elasticity, dielectric constant, conductivity, etc.) of the individual liquid elements of a library of materials.

Abstract: An analyte, viscosity, or temperature sensing apparatus for operative arrangement within a time-varying magnetic field, including a sensor with an outer surface that is chemically, frictionally, or thermally responsive and adhered to a base magnetostrictive element, and a receiver to measure a first and second value for magneto-elastic emission intensity of the sensor taken at, respectively, a first and second interrogation frequency. A change in mass or a change in material stiffness of the sensor due to the responsiveness, the viscosity and mass density of a fluid therearound, or the temperature, can be identified. The receiver, alternatively, measures a plurality of successive values for magneto-elastic emission intensity of the sensor taken over an operating range of successive interrogation frequencies to identify a value for the sensor's magneto-elastic resonant frequency (a fundamental frequency or harmonic thereof).

Abstract: A method and apparatus for measuring properties of a liquid composition includes a mechanical resonator, such as a thickness shear mode resonator or a tuning fork resonator, connected to a measurement circuit. The measurement circuit provides a variable frequency input signal to the tuning fork, causing the mechanical resonator to oscillate. To test the properties of a liquid composition, the mechanical resonator is placed inside a sample well containing a small amount of the liquid. The input signal is then sent to the mechanical resonator and swept over a selected frequency range, preferably less than 1 MHz to prevent the liquid being tested from exhibiting gel-like characteristics and causing false readings. The mechanical resonator's response over the frequency range depends on various characteristics of the liquid being tested, such as the temperature, viscosity, and other physical properties.

Abstract: There is provided a double-headed mass sensor (25) in which between a first connecting plate (22A) joined to a first diaphragm (21A) at respective sides and a second connecting plate (22B) joined to a second diaphragm (21B) at respective sides, a first sensing plate (41A), on which a main element (44) is provided on at least one plane surface, is bridged, and a resonating portion comprising the diaphragms (21A), (21B), the connecting plates (22A), (22B), the first sensing plate (41A) and the main element (44) is joined to a sensor substrate (27). Change in the mass of each of the diaphragms (21A), (21B) is measured by measuring change in the resonant frequency of the resonating portion accompanying the change in the mass of the diaphragms (21A), (21B). The mass sensor of the present invention enables the easy and highly accurate measurement of a minute mass of a nanogram order including microorganisms such as bacteria and viruses, chemical substances, and the thickness of vapor-deposited films.

Abstract: An apparatus and related method for measuring the degree of stratified flow in a two-phase flow is disclosed. Alternate embodiments include a single transducer level detector and a multiple transducer level detector. Further, these level detectors may be either integrated into or used in conjunction with an ultrasonic flow meter, or may be used in conjunction with some other meter that determines speed of sound for the flowing gas.

Abstract: Provided are a measurement apparatus and a measurement system comprising sample and reference microresonators, such as sample and reference quartz crystal microbalances; sample and reference heat flow sensors; and a heat sink coupled thermally to the heat flow sensors. These may be used to measure changes in one or more properties, such as mass, due to a liquid sample on a surface of a sample microresonator and also to measure heat flows from the sample on the surface of the sample microresonator by utilizing the heat flow sensors, which are coupled thermally to the corresponding sample or reference microresonators. Also provided is a method for measuring one or more properties, such as mass, of a liquid sample and the flow of heat from the sample to the heat sink by utilizing such apparatus.

Abstract: At least one parameter of at least one fluid in a pipe 12 is measured using a spatial array of acoustic pressure sensors 14,16,18 placed at predetermined axial locations x1,x2,x3 along the pipe 12. The pressure sensors 14,16,18 provide acoustic pressure signals P1(t), P2(t), P3(t) on lines 20,22,24 which are provided to signal processing logic 60 which determines the speed of sound amix of the fluid (or mixture) in the pipe 12 using acoustic spatial array signal processing techniques with the direction of propagation of the acoustic signals along the longitudinal axis of the pipe 12. Numerous spatial array processing techniques may be employed to determined the speed of sound amix. The speed of sound amix is provided to logic 48 which calculates the percent composition of the mixture, e.g., water fraction, or any other parameter of the mixture or fluid which is related to the sound speed amix. The logic 60 may also determine the Mach number Mx of the fluid.

Abstract: A method and apparatus for measuring properties of fluid flowing through a bore, using a signal transmitted substantially perpendicularly to the direction of flow. A preferred embodiment uses a pair of acoustic transducers mounted in the annular body of the fluid conduit. The tool is constructed so as to be able to operate for a period of years in a downhole environment without maintenance or replacement. An transducer is also described that is adapted to fit within the dimensions of an annular body without suffering a reduction in the length of the transducer backing.

Abstract: In a method of analyzing a concentration of a target substance contained in a fluid using a quartz oscillator having a surface covered with a layer capable of absorbing the target substance, the temperature of the fluid and the quartz oscillator is controlled at substantially the same predetermined temperature selected according to the concentration of the target substance in said fluid, so that the analysis can be made with optimum sensitivity. A device for analyzing a concentration of a target substance contained in a fluid, includes a contacting chamber accommodating a quartz oscillator, a temperature controller, disposed in a feed passage for feeding the fluid into said contacting chamber, for adjusting a temperature of the fluid at a desired predetermined temperature; and a detector of a frequency of the quartz oscillator.

Abstract: A method and apparatus for measuring properties of a fluid composition 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. To test the properties of a liquid composition, the mechanical resonator is placed inside a sample well containing a small amount of the fluid. 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. The invention is particularly suitable for combinatorial chemistry applications, which require rapid analysis of chemical properties for screening.

Abstract: A method of calculating the salt content of water in a multiphase flow which comprises irradiating a body of the multiphase flow with radiation of three distinct energy levels; measuring the intensity of the transmitted radiation at each of the energy levels, and using the measurements of transmitted radiation as obtained from calibration and radiation mass attenuation coefficients for hydrocarbons for each of the energy levels, to calculate a unique function for representing the salt content of the water. The three energy levels can as an example be provided by the radioactive isotope Barium 133 and the radiation mass attenuation coefficients for hydrocarbons can be calculated theoretically or derived from static calibration measurements. The invention is particularly suited for the measurement of water salinity in a stream comprising a mixture of oil, water, and gas, i.e., a multiphase flow, without separating the phases.

Abstract: A improvement for high precision ultrasonic chilled surface dew point hygrometry for measuring the density of condensation and the temperature at the same location on the surface of the sensor. The improvement for high precision ultrasonic chilled surface dew point hygrometry includes a piezoelectric substrate, and further having a conventional thermoelectric cooler connected thereto and a plurality of spaced heat sinks conventionally depending from the surface. Conventional acoustic devices are used to propagate surface acoustic waves and surface skimming bulk waves across the surface of the sensor. A series of the surface acoustic waves is used to measure the density of the condensation at a particular location on the surface of the sensor.

Abstract: A process and device are disclosed for recognizing foreign bodies in viscous or fluid masses with lumpy foodstuffs. The mass to be checked runs through a measurement section, in which, pulsed ultrasonic signals are emitted through the mass, are reflected after passing through the mass, and after passing again through the mass they are received and compared with the ultrasonic echo of the reflection surface. When the changes of the received signals exceed a predetermined threshold value, a warning or actuating signal is generated to interrupt mass advance. The parameters to be evaluated for the signal may be their amplitudes, as well as the speed of change of their amplitudes or the propagation times.

Abstract: In a sensor comprising a housing, through which a medium to be examined is conducted, the housing includes at least two passive building components capable of oscillating and oscillator circuits of which each includes an amplifier component and a variable phase shifting component providing for a phase shift range sufficiently large to switch the oscillating components off while the amplifier component remains operating.

Abstract: A method and apparatus for real time gas analysis involving determining individual concentrations of fluid constituents in a mixture of known constituents by measuring properties of the mixture and solving a set of equations, which relate the individual gas concentrations to the measured properties of the mixture, for the unknown individual gas concentrations. The individual concentrations of four gasses in a mixture are determined by: passing the mixture through a flowmeter, a capillary, an orifice, and a sonic oscillator; transducing temperature, pressure and acoustic frequency measurements taken from the sensors; determining the density, viscosity, and the specific heat of the mixture; forming three equations which respectively relate these three properties to individual gas concentrations; and solving the three equations and the constitutive equation which requires that the sum of the concentrations equal unity, for the four unknown individual gas concentrations.

Abstract: An ultrasonic sensor system and method of use for measuring transit time though a liquid sample, using one ultrasonic transducer coupled to a precision time interval counter. The timing circuit captures changes in transit time, representing small changes in the velocity of sound transmitted, over necessarily small time intervals (nanoseconds) and uses the transit time changes to identify the presence of non-conforming constituents in the sample.

Abstract: A surface acoustic wave device sensor configured so as to have at least two different modes of operation. An acoustic response is obtained from each of the different modes of operation. The different modes of operation are a combination of a temperature effect and a measurand effect. The measurand effect is caused by the absorption and/or adsorption of a substance into a selective coating on the piezoelectric substrate. The two different modes of operation are effected differently by the temperature effect and therefore can be used to effectively eliminate the temperature effect by simultaneously solving equations representative of the different modes of operation. The present invention eliminates the need to provide other relatively more complicated temperature compensating structure or to maintain the device at a predetermined constant temperature. The present invention can be used to detect different chemicals or substances.

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.

Abstract: An apparatus for detecting gas bubbles, in a liquid flow, comprises a one-piece housing (1) of a material that is transmissive to ultrasound, a liquid passage (2) extending through the housing (1), inlet and outlet means on the housing (1) for connecting the liquid passage (2) to the liquid flow, and ultrasonic transducer means (3, 4) on the housing on each side of the liquid passage (2), one transducer means being arranged as sender and the other transducer means being arranged as receiver, with the liquid passage (2) positioned in the sound transmission path between the sender and the receiver, whereby inhomogeneities in the liquid flow can be detected based on the emitted ultrasound energy that is received by the receiver. The housing (1) has two opposed recesses (6, 7), one on the sender side of the liquid passage (2) and one on the receiver side thereof, which recesses in a direction perpendicular to the sound transmission path as well as to the liquid passage.

Abstract: An apparatus and related method for measuring the properties and individual flow rates of a two-phase flow comprising a gas and a liquid is disclosed. This apparatus and related method also can determine whether the liquid is travelling in primarily a mist or stratified flow. More precisely, one embodiment of the disclosed invention uses measured parameters such as gain, standard deviation in upstream and downstream travel times for an ultrasonic signal, measured speed of sound, noise, signal quality, batch failure rate, and velocity profile to infer the amount of liquid in the gas flow, and in what form the liquid is travelling. For a horizontal two-phase flow, an internal measurement can be used as a dry gas reference, although the invention is also applicable to a vertical flow. For increased confidence, these determinations may be corroborated by the disclosed liquid level measurement device.

Abstract: A non-invasive elastic wave fluid level sensing system for use in sludge laden environments, including transmitting and receiving transducers mounted on an outer face of a wall of a container for a fluid and along a propagation path for an elastic wave transmitted through the wall of the container wherein the elastic wave has a frequency of less than 5 kHz, more preferably less than about 2 kHz, and most preferably less than 1 kHz. A signal processor determines a change in a characteristic of the elastic wave between when a fluid is present in the container in the region of the propagation path and when a fluid is not present in the container in the region of the propagation path. One embodiment utilizes multiple horizontally oriented transmitting and receiving transducer pairs to detect levels of the fluid in the container.

Abstract: Provided is a mass and heat flow measurement apparatus comprising sample and reference microresonators, such as sample and reference quartz crystal microbalances; sample and reference heat flow sensors, such as sample and reference isothermal heat conduction calorimeters; and sample and reference heat sinks coupled thermally to the heat flow sensors. The apparatus may be used to measure changes in mass due to a sample on a surface of the sample microresonator and also to measure heat flows from the sample on the surface of the sample microresonator by utilizing the heat flow sensors, which are coupled thermally to the corresponding sample or reference microresonators. Also provided is a method for measuring the mass of a sample and the flow of heat from the sample to the heat sink by utilizing such apparatus.

Abstract: Methods and apparatus for screening diverse arrays of materials are provided. In one aspect, systems and methods are provided for imaging a library of materials using ultrasonic imaging techniques. The system includes one or more devices for exciting an element of the library such that acoustic waves are propagated through, and from, the element. The acoustic waves propagated from the element are detected and processed to yield a visual image of the library element. The acoustic wave data can also be processed to obtain information about the elastic properties of the library element. In another aspect, systems and methods are provided for generating acoustic waves in a tank filled with a coupling liquid. The library of materials is then placed in the tank and the surface of the coupling liquid is scanned with a laser beam. The structure of the liquid surface disturbed by the acoustic wave is recorded, the recorded disturbance being representative of the physical structure of the library.

Abstract: An improved method of fluid analysis in the borehole of a well. A fluid sampling tool is fitted with a pumpout module that can be used to draw fluids from the formation, circulate them through the instrument, and then expel this fluid to the borehole. It has been determined that certain measurements would be most valuable to implement down hole, such as the formation fluid bubble point and dew point. Accurate bubble point and dew point measurements are made by forming bubbles or a liquid drop in a measured sample, and detecting same.