Abstract: To provide a sensing device capable of easily sensing a substance to be sensed with high accuracy. When sensing, by supplying a sample solution to an absorption layer 46 while oscillating a quartz-crystal resonator 4 to make the absorption layer absorb a substance to be sensed in the sample solution, the substance to be sensed based on an amount of variation in an oscillation frequency of the quartz-crystal resonator 4 after an absorption time elapses, the quartz-crystal resonator 4 is oscillated, before supplying the sample solution to the absorption layer 46, to measure the oscillation frequency of the quartz-crystal resonator 4 at a predetermined measurement interval, for instance, at every one second, and the oscillation frequency of the quartz-crystal resonator 4 is stabilized for the same period of time as a measuring time 19 until the measurement result becomes equal to or less than a frequency tolerance value 19b previously set based on a measurement sensitivity of the substance to be sensed.

Abstract: There is disclosed an apparatus and method for detecting cavitation in fluid machines, for example pumps (100). In one embodiment a piezoelectric gasket (102) is used as a sensor to sense cavitation. In some embodiments highpass filters (302), (501) are used to detect ultrasonic acoustic signals in about the MHz range. If the energy in the MHz range is excessive then cavitation is deemed to be occurring and the speed of a motor (110) may be reduced in proportion to the degree of cavitation deemed to be occurring. In another embodiment (FIG. 5) the energy in the MHz range is normalised against the energy in the kHz range. Other sensors (600, 701) are also disclosed.

Abstract: In a method for production of a polycrystalline ceramic film on a substrate: a) the substrate is prepared with the substrate surface and preparation of at least one source for the ceramic particles of the ceramic film and b) a particle stream of the ceramic particles is generated from the source of ceramic particles in the direction of the substrate surface on the substrate, with deposition of the ceramic particles on the substrate surface on the substrate with formation of the ceramic film. At least one screen is arranged within the gap, for adjusting an average incidence angle of the ceramic particles relative to a plane normal of the substrate surface, such that the ceramic particles are deposited on the substrate surface at a preferred direction and a relative position of the substrate surface and the screen is altered whilst the gap remains essentially the same.

Abstract: An assembly design for an oscillating resonator-based sensor where an oscillating crystal resonator such as a quartz crystal resonator is rigidly affixed or ‘mounted’ onto a solid substrate in such a fashion that the resonator can either rest flush against the substrate surface or upon a rigid mounting adhesive. Once cured, the mounting adhesive forms a liquid tight seal between the mounted resonator and the substrate such that only the sensing electrode surface will be exposed to fluids applied to the front side of the substrate. The mounted resonator assembly is designed in such a way that it can be interfaced with a fluid delivery system to form a liquid tight chamber or flow cell around the mounted resonator without incurring additional physical impact upon the mounted resonator.

Abstract: A Monolithic Antenna Excited Acoustic Transduction (MAEAT) device is fabricated by photolithographically depositing a metallic antenna on one side of a piezoelectric crystal substrate.

Abstract: The invention provides devices and methods for acoustically determining the properties of the contents of one or more reservoirs in a plurality of reservoirs. Each reservoir is adapted to contain a fluid. An acoustic radiation generator can be positioned in acoustic coupling relationship to each of the reservoirs. Acoustic radiation generated by the acoustic radiation generator is transmitted through each reservoir to an analyzer. The analyzer is capable of analyzing a characteristic of the transmitted acoustic radiation and optionally correlating the characteristic to a property of the reservoirs' contents. Properties that may be determined include volume, temperature, and composition. The invention is particularly suited to determining the properties of the contents of a plurality of reservoirs to allow for accuracy and control over the dispensing of fluids therefrom.

Abstract: A mechanical resonator capable of providing an intrinsically high mechanical quality factor in immersion is provided. The resonator includes a membrane attached at its perimeter to a frame, such that a front side of the membrane is in contact with the liquid, and the back side of the membrane is not in contact with the liquid or the frame. The membrane can act as a mechanical resonator. The quality factor of this resonator is enhanced by providing a pressure release boundary region on the frame in proximity to the membrane and in contact with the liquid. The pressure release boundary region provides a soft boundary condition, in the sense that a mechanical impedance on the solid side of the solid-liquid interface is less than the liquid mechanical impedance. Providing such a soft boundary condition reduces the mechanical energy loss due to excitation of waves in the liquid, thereby improving resonator quality factor. Such high-Q resonators are particularly useful for sensor applications.

Abstract: Techniques are described for estimating the propagation velocity through a surface acoustic wave sensor. In particular, techniques which measure and exploit a proper segment of phase frequency response of the surface acoustic wave sensor are described for use as a basis of bacterial detection by the sensor. As described, use of velocity estimation based on a proper segment of phase frequency response has advantages over conventional techniques that use phase shift as the basis for detection.

Abstract: An ultrasonic wave passes different fuels of different concentrations with different velocities. The present invention provides a detecting and controlling device where, by a non-touching method, a velocity for an ultrasonic wave in a first fuel with a first fuel concentration is measured. The velocity obtained is taken for a comparison with another velocity for the same ultrasonic wave in a fuel with a default fuel concentration so that the first fuel concentration of the fuel can be under controlled.

Abstract: A self-checking analyzer system is provided according to an embodiment of this disclosure. The analyzer system includes a pipeline for receiving a multi-phase fluid flow and a first measuring device configured to provide a first frequency response corresponding to the multi-phase fluid flow. The analyzer system also includes a second measuring device differing in frequency response from the first measuring device and configured to provide a second frequency response corresponding to the multi-phase fluid flow. The analyzer system is configured to validate the first frequency response using the second frequency response.

Abstract: Fluid sensor methods and systems adapted for monitoring and/or controlling distillation operations in fluidic systems, such as batch distillation operations or continuous distillation operations, are disclosed. Preferred embodiments are directed to process monitoring and/or process control for unit operations involving endpoint determination of a distillation, for example, as applied to a liquid-component-switching operation (e.g., a solvent switching operation), a liquid-liquid separation operation, a solute concentration operation, a dispersed-phase concentration operation, among others.

Abstract: A device for measurement of entrained and dissolved gas has a first module arranged in relation to a process line for providing a first signal containing information about a sensed entrained air/gas in a fluid or process mixture flowing in the process line at a process line pressure. The device features a combination of a bleed line, a second module and a third module. The bleed line is coupled to the process line for bleeding a portion of the fluid or process mixture from the process line at a bleed line pressure that is lower than the process pressure. The second module is arranged in relation to the bleed line, for providing a second signal containing information about a sensed bleed line entrained air/gas in the fluid or process mixture flowing in the bleed line.

Abstract: A thickness shear mode (TSM) sensor having a visco-elastic polymer coating and a fundamental frequency greater than 20 MHz useful for organic vapor or gas detection. The TSM quartz resonators at a fundamental frequency of 96 MHz were evaluated for their performance in organic vapor sensing applications and results were compared with the performance of 10 and 20 MHz resonators. These devices were produced by chemical milling of AT-cut quartz. Seven test organic vapors were utilized at concentrations ranging from 0.2 volume percent to 13.7 volume percent in the vapor phase. In all cases, the rubbery polymer polyisobutylene was used as a sensing layer. Detailed results for various sensor parameters such as sensitivity, baseline noise and drift, limit of detection, response and recovery times, dynamic range, and repeatability for the 96 MHz device were compared with those for 10 and 20 MHz devices. The test case of benzene/polyisobutylene was chosen to make these detailed comparisons.

Abstract: The present invention provides a metal-ion sensor characterized by coating the gold electrode of a quartz crystal microbalance (QCM) with melanin, whereby the sensor has an enhanced sensitivity to metal ions.

Abstract: A method and apparatus for determining at least one flow parameter of a fluid flowing within a pipe, which fluid contains particles entrained within the fluid flow is provided. The method includes the steps of: 1) determining a velocity of the fluid flow within the pipe; 2) sensing the impingement of particles on a surface wetted with the fluid flow, and producing a signal relating to the impingement; and 3) determining the at least one flow parameter of the fluid flow utilizing the determined fluid flow velocity and the sensor signal relating to impingement of the particles on the surface wetted with the fluid flow.

Abstract: A submersible meter is provided that measures the speed of sound propagating in an aerated fluid to determine any one of a plurality of parameters of the fluid, such as the gas holdup of the fluid (?b), the bubble size (db), the bubble surface area flux (Sb), and the flotation rate constant (k). The meter includes a spatial array of sensors disposed at predetermined axial locations x1-XN axially along a tube. The array of sensors provide acoustic pressure signals P1(t)-PN(t) to a transmitter which determines the speed of sound amix propagating through the aerated fluid in the tube using acoustic spatial array signal processing techniques. The submersible meter enables real time measurement of the bubble size, the bubble surface area flux and flotation rate constant, which enables real time monitoring of the efficiency and recovery rate of flotation machines.

Abstract: A measuring method using a surface acoustic wave device, with which even in a case where a target substance having a different viscosity is added to a buffer liquid on the surface acoustic wave device it is possible to measure a mass load accurately without suffering an effect of this viscous load, and it is also possible to shorten the time taken for the temperature of the buffer liquid to stabilize and thereby shorten the time taken for the measurement.

Abstract: A method and apparatus for testing a hydrocarbon sample. The apparatus includes a sheath disposed about the hydrocarbon sample container and at least one set of acoustic sensors, wherein the at least one set of acoustic sensors is secured to the sheath, and further wherein at least one set of acoustic sensors produces an acoustic signal having a velocity through the hydrocarbon sample. In addition, the velocity is measured to provide information about the hydrocarbon sample. In other embodiments, the at least one set of acoustic sensors is disposed radially about the hydrocarbon sample.

Abstract: This invention relates to a liquid measurement cell for micromechanical sensors, so-called cantilever sensors. These sensors are e.g. used for the detection of biomolecules without the need for fluorescent or radioactive labelling. These measurements are usually carried out in liquids, where air or gas bubbles present in the analyte inside the measurement cell can significantly affect measurement results or even destroy the sensor. In a measurement cell according to this invention, a closed gas volume is present above the liquid level. Consequently, gas or air bubble can be constantly absorbed by the gas volume and do not come in contact with the cantilever sensors. The measurement cell is further characterised by a very low volume in the order of microliters and can be combined with various optical or piezoelectrical/piezoresistive read-out methods.

Abstract: An object of the present invention is to provide a Langevin type quartz sensor which is high in measurement sensitivity, suppresses the influence of the surface tension of a sample solution during measurement, and enables an installed quartz resonator to stably oscillate.

Abstract: Methods for monitoring a fluid composition include placing a mechanical resonator in the fluid composition and oscillating the resonator. The resonator can be a tuning fork resonator having tines oscillated in opposite directions and in opposite phases. A variable frequency input signal can be varied over a predetermined frequency range and oscillate the mechanical resonator at less than 1 MHz. A frequency-dependent resonator response curve can be stored in a computer memory and fitted to a model curve to monitor the fluid. The resonator can be coated with a protective coating. The resonator can be treated with a functionality designed to change a resonance frequency of the resonator after being exposed to a selected target chemical and the resonance frequency monitored to detect presence of the target chemical.

Abstract: A measurement method and a biosensor apparatus using a resonator with which it is not necessary to agitate a sample solution in a cell and even if the amount of the sample solution is very small the influence of pressure waves is greatly reduced and extremely easy and accurate measurement is possible. In a method of the kind wherein a sample solution is brought into contact with one side of a resonator having first and second electrodes on opposite sides of a crystal plate and an a.c. signal is applied across the first and second electrodes and a frequency change of the resonator is measured from a relationship between the frequency of the a.c. signal and an electrical characteristic of the resonator, the resonator is made to oscillate at an N-tuple harmonic (N=3, 5, 7 . . . ) as the frequency change is measured.

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: An apparatus 10 and method is provided that includes a spatial array of unsteady pressure sensors 15-18 placed at predetermined axial locations x1-xN disposed axially along a pipe 14 for measuring at least one parameter of a solid particle/fluid mixture 12 flowing in the pipe 14. The pressure sensors 15-18 provide acoustic pressure signals P1(t)-PN(t) to a signal processing unit 30 which determines the speed of sound amix(?) of the particle/fluid mixture 12 in the pipe 14 using acoustic spatial array signal processing techniques. The primary parameters to be measured include fluid/particle concentration, fluid/particle mixture volumetric flow, and particle size. Frequency based sound speed is determined utilizing a dispersion model to determine the parameters of interest. the calculating the at least one parameter uses an acoustic pressure to calculate.

Abstract: Techniques for measuring a density of a liquid within a fluid that includes both a liquid and a gas are described. A pressure of the fluid oscillates according to a time-varying function, which causes a density of the fluid also to oscillate according to the same time-varying function. A resulting pressure signal and density signal are analyzed to extract at least a first and second pressure value and at least a first and second density value, where the first pressure and density values occur at a first time, and the second pressure and density values occur at a second time. Then, the liquid density is calculated from the first and second pressure and density values. As a result, the liquid density may be calculated quickly and easily, with a minimum of effort on the part of an operator, and without requiring disruption of other measurement processes associated with the flowtube.

Abstract: An apparatus for measuring at least one parameter associated with a fluid flowing within a pipe includes a spatial array of pressure sensors disposed at different axial locations x1. . . xN along the pipe. Each of the pressure sensors provides a pressure signal P(t) indicative of unsteady pressure within the pipe at a corresponding axial location of the pipe. A signal processor receives the pressure signals from each of the pressure sensors and determines the parameter of the fluid using pressure signals from selected ones of the pressure sensors. By selecting different pressure sensors, the signal processor can configure the array to meet different criteria. In one embodiment, the array of pressure sensors may be formed on a single sheet of polyvinylidene fluoride (PVDF) that is wrapped around at least a portion of an outer surface of the pipe. This arrangement allows a large number of pressure sensors to be quickly and economically installed.

Abstract: An on-chip coil is provided in a micromachined device for magnetic actuation of a nanoelectromechanical microcantilever. The novel geometry involves a three dimensional solenoid or planar coil carrying high current that generates a large enough magnetic field in its close proximity to a permalloy thin film patch or columnar magnet disposed on the distal end of the piezoresistive microcantilever to effectively interacts with the magnetic thin film deposited on the microcantilever. The device comprises an effective actuators which can be integrated with biofunctionalized cantilever arrays in hybrid semiconductor-microfluidics devices for the analysis and detection of biological analytes.

Abstract: Method for determining the composition of a homogeneous fluid, for example a petroleum effluent on flow, an emulsion consisting of water and oil, or a foam consisting of oil and gas. The attenuation and the phase shift of microwave beams that have traversed a fluid of unknown composition with paths of different lengths are measured (stage A). Two equations approaching the measured values are determined, the first equation giving a relation between the attenuation and the length of the path, the second equation giving a relation between the phase shift and the length of the path (stage C). Then the composition of the fluid is determined by comparing the two equations with pairs of equations stored in form of databases, each pair of equations corresponding to a fluid of known composition (stage D).

Abstract: Techniques for measuring a density of a liquid within a fluid that includes both a liquid and a gas are described. A pressure of the fluid oscillates according to a time-varying function, which causes a density of the fluid also to oscillate according to the same time-varying function. A resulting pressure signal and density signal are analyzed to extract at least a first and second pressure value and at least a first and second density value, where the first pressure and density values occur at a first time, and the second pressure and density values occur at a second time. Then, the liquid density is calculated from the first and second pressure and density values. As a result, the liquid density may be calculated quickly and easily, with a minimum of effort on the part of an operator, and without requiring disruption of other measurement processes associated with the flowtube.

Abstract: A device (1) for determining the qualify of a medium, particularly of a lubricant and/or cutting oil, includes a number of sensors (3, 4, 5, 6, 7) that emit electric output signals according to the respective sensor-specific input variables. One sensor is a temperature sensor (7) that emits an output signal, which is essentially only dependent on the temperature (T) of the medium and is essentially independent of, in particular, the quality of the medium. At least one other sensor (3, 4, 5, 6) emits an output signal that is dependent on both the quality of the medium as well as the temperature (T) of the medium. The sensors (3, 4, 5, 6, 7) are placed on a shared substrate (2) that can be immersed in the medium. An associated process also determines the quality of a medium.

Abstract: A device for measurement of entrained and dissolved gas has a first module arranged in relation to a process line for providing a first signal containing information about a sensed entrained air/gas in a fluid or process mixture flowing in the process line at a process line pressure. The device features a combination of a bleed line, a second module and a third module. The bleed line is coupled to the process line for bleeding a portion of the fluid or process mixture from the process line at a bleed line pressure that is lower than the process pressure. The second module is arranged in relation to the bleed line, for providing a second signal containing information about a sensed bleed line entrained air/gas in the fluid or process mixture flowing in the bleed line.

Abstract: A method and apparatus for measuring properties of a liquid composition includes a mechanical resonator, such as a cantilever, connected to a measurement circuit. The mechanical resonator can be covered with a coating to impart additional special detection propertied to the resonator, and multiple resonators can be attached together as a single sensor to obtain multiple frequency responses. The invention is particularly suitable for combinatorial chemistry applications, which require rapid analysis of chemical properties for screening. In one embodiment, the resonator is operated at a frequency of less than 1 MHz.

Abstract: The present invention discloses an apparatus for determining the density and the phase fraction of a fluid flowing in a conduit. The apparatus comprises a fiber optic density meter situated along the conduit that provides a signal indicative of the density of the fluid. The density meter includes two sound speed meters disposed at different sensing regions along the pipe. The sensing regions have a substantially different cross sectional area compliance. Each sound speed meter measures an acoustic pressure within the pipe at its corresponding axial location and provides a signal indicative of the effective fluid sound speed at its corresponding sensing region. Because each sensing region has a substantially different cross sectional area compliance, the density of the fluid is determined by the difference between the effective fluid sound speed signals. From the effective sound speed at either sensing region or from a separate acoustic sensor array, the infinite fluid sound speed may be determined.

Abstract: A plurality of quartz crystal resonators having different resonance frequencies are connected in parallel. A combined admittance of the resonators is measured. Equivalent circuit constants of all the resonators are obtained by a method of least squares from admittance characteristics. A change in the resonance frequency is measured and mass of a substance adsorbed to a piezoelectric transducer is calculated.

Abstract: A method for detecting the presence of particles, such as sand, flowing within a fluid in a conduit is disclosed. At least two optical sensors measure pressure variations propagating through the fluid. These pressure variations are caused by acoustic noise generated by typical background noises of the well production environment and from sand particles flowing within the fluid. If the acoustics are sufficiently energetic with respect to other disturbances, the signals provided by the sensors will form an acoustic ridge on a k? plot, where each data point represents the power of the acoustic wave corresponding to that particular wave number and temporal frequency. A sand metric then compares the average power of the data points forming the acoustic ridge to the average power of the data points falling outside of the acoustic ridge. The result of this comparison allows one to determine whether particles are present within the fluid.

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: The disclosed apparatus comprises a phase fraction meter and a compliant mandrel deployable within a production pipe, and may further comprise a flow velocity meter. The mandrel allows the determination of the phase fraction for a fluid comprising three phases by providing an additional cross sectional compliance within the conduit, thereby allowing the density of the fluid to be determined. The mandrel also provides a specified blockage through the flow velocity meter, thereby increasing flow velocity through the meter. This allows flow rate measurements in conditions under which flow velocity in the under-restricted cross-sectional area of the pipe would normally be very low. Further, the mandrel can provide a specified restriction in the pipe, i.e., a venturi. By measuring the differential pressure across the venturi and utilizing the measured fluid velocity from the flow velocity meter, the density of the fluid mixture can be calculated.

Abstract: A method for measuring properties of a fluid that includes oscillating a tuning fork resonator in a fluid. The invention is particularly suitable for in-line monitoring of various physical and electrical properties of fluids flowing in a conduit.

Abstract: In a mass-sensitive sensor consisting of an acoustic surface wave component on the basis of shear waves, the sensor includes a substrate with an active surface carrying two different layers, one which is a parylene layer of a thickness of between 0.2 and <1.6 ?m, which has been produced on the substrate by a vacuum-based deposition method and is capable of generating Love waves and the second layer forms a utilization layer, which interacts with an analyte disposed in a medium contacting the utilization layer.

Abstract: A method is described which applies Acoustic Spectrometry to characterize both the particle size distribution and micro-rheological properties of the structured concentrated dispersions. It suggests to model the structured dispersion as a collection of the spherical particles which are connected together with flexible strings. Oscillation of these strings creates an additional energy dissipation which contributes to the total attenuation. This dissipation is dependent on the second virial coefficient characterizing the flexibility of the strings. It is shown that the value of the second virial coefficient can be calculated from the measured attenuation spectra either for known particle size or together with particle size as adjustable parameter.

Abstract: A method and apparatus for measuring properties of a liquid composition includes a mechanical resonator, such as a cantilever, connected to a measurement circuit. 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. The invention is particularly suitable for combinatorial chemistry applications, which require rapid analysis of chemical properties for screening.

Abstract: An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.

Abstract: At least one parameter of at least one fluid in a pipe is measured using a spatial array of acoustic pressure sensors placed at predetermined axial locations along the pipe 12. The pressure sensors provide acoustic pressure signals, which are provided to a signal processing system that determines the speed of sound amix of the fluid (or mixture) in the pipe 12 using acoustic spatial array signal processing techniques. Numerous spatial array processing techniques may be employed to determine the speed of sound amix. The speed of sound amix is provided to another logic system that 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 signal processing system may also determine the Mach number Mx of the fluid. The acoustic pressure signals measured are lower frequency (and longer wavelength) signals than those used for ultrasonic flow meters, and thus are more tolerant to inhomogeneities in the flow.

Abstract: An analytical apparatus, such as a quartz crystal microbalance, comprises 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 maintains a substantially constant drive signal to the piezoelectric sensor by an AGC (33) within a feedback loop of the oscillator. The gain control signal is used as an indication of the Q of the piezoelectric sensor. The drive signal to the sensor is made substantially sinusoidal 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 method for detecting the presence of particles, such as sand, flowing within a fluid in a conduit is disclosed. At least two optical sensors measure pressure variations propagating through the fluid. These pressure variations are caused by acoustic noise generated by typical background noises of the well production environment and from sand particles flowing within the fluid. If the acoustics are sufficiently energetic with respect to other disturbances, the signals provided by the sensors will form an acoustic ridge on a k? plot, where each data point represents the power of the acoustic wave corresponding to that particular wave number and temporal frequency. A sand metric then compares the average power of the data points forming the acoustic ridge to the average power of the data points falling outside of the acoustic ridge. The result of this comparison allows one to determine whether particles are present within the fluid.

Abstract: A liquid sample sensing device comprises a set of stackable liquid sample base units that are adapted to be stacked together to form multiple sample volumes that are substantially sealed, each with an electroacoustic member disposed therein having a surface adapted for binding to a particular target molecule. Top and bottom units are preferably attached to a closed loop of flexible tubing and a peristaltic pump. Individual electroacoustic members in the stack can each be adapted to bind with different target molecules, allowing for a multiple target assay. Alternately, a plurality of electroacoustic members can be adapted to bind with the same type of target molecule, thereby increasing the sensitivity of the sensing device. The base units are adapted such that sample liquid is caused to flow over and be in close proximity to the sensing surface of each electroacoustic member as the sample liquid flows from one base unit to the next, thereby increasing the efficiency of binding.

Abstract: A liquid sample sensing device comprises a set of stackable liquid sample base units that are adapted to be stacked together to form multiple sample volumes that are substantially sealed, each with an electroacoustic member disposed therein having a surface adapted for binding to a particular target molecule. Top and bottom units are preferably attached to a closed loop of flexible tubing and a peristaltic pump. Individual electroacoustic members in the stack can each be adapted to bind with different target molecules, allowing for a multiple target assay. Alternately, a plurality of electroacoustic members can be adapted to bind with the same type of target molecule, thereby increasing the sensitivity of the sensing device. The base units are adapted such that sample liquid is caused to flow over and be in close proximity to the sensing surface of each electroacoustic member as the sample liquid flows from one base unit to the next, thereby increasing the efficiency of binding.

Abstract: A method for detecting the presence of particles, such as sand, flowing within a fluid in a conduit is disclosed. At least two optical sensors measure pressure variations propagating through the fluid. These pressure variations are caused by acoustic noise generated by typical background noises of the well production environment and from sand particles flowing within the fluid. If the acoustics are sufficiently energetic with respect to other disturbances, the signals provided by the sensors will form an acoustic ridge on a k&ohgr; plot, where each data point represents the power of the acoustic wave corresponding to that particular wave number and temporal frequency. A sand metric then compares the average power of the data points forming the acoustic ridge to the average power of the data points falling outside of the acoustic ridge. The result of this comparison allows one to determine whether particles are present within 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.

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.