WO2012031305A1 - Method for noninvasive determination of acoustic properties of fluids inside pipes - Google Patents
Method for noninvasive determination of acoustic properties of fluids inside pipes Download PDFInfo
- Publication number
- WO2012031305A1 WO2012031305A1 PCT/US2011/050583 US2011050583W WO2012031305A1 WO 2012031305 A1 WO2012031305 A1 WO 2012031305A1 US 2011050583 W US2011050583 W US 2011050583W WO 2012031305 A1 WO2012031305 A1 WO 2012031305A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- signal
- pipe
- chirp signal
- frequency chirp
- time
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/02—Analysing fluids
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/02—Analysing fluids
- G01N29/024—Analysing fluids by measuring propagation velocity or propagation time of acoustic waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/74—Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F17/00—Methods or apparatus for determining the capacity of containers or cavities, or the volume of solid bodies
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/222—Constructional or flow details for analysing fluids
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/34—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor
- G01N29/348—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor with frequency characteristics, e.g. single frequency signals, chirp signals
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
- G01N29/4454—Signal recognition, e.g. specific values or portions, signal events, signatures
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
- G01N29/50—Processing the detected response signal, e.g. electronic circuits specially adapted therefor using auto-correlation techniques or cross-correlation techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/022—Liquids
- G01N2291/0222—Binary liquids
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/022—Liquids
- G01N2291/0224—Mixtures of three or more liquids
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/04—Wave modes and trajectories
- G01N2291/048—Transmission, i.e. analysed material between transmitter and receiver
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/10—Number of transducers
- G01N2291/102—Number of transducers one emitter, one receiver
Definitions
- the present invention relates generally to a method for determining the composition of fluids flowing through pipes and, more particularly, to a method for noninvasively determining sound speed and sound attenuation of fluids flowing through thick-walled pipes and conduits for determining the composition of the fluid.
- acoustic measurements for example, sound speed and sound absorption in liquids
- sensors attached to the pipe through special windows machined into the pipe wall where the sensor elements make physical contact with the fluid or are mounted directly in the fluid.
- the sensors or the windows are subject to fouling by the fluid, making long-term operation and maintenance difficult.
- a sensor is placed inside the fluid or intrudes into the liquid through the wall, it can affect the flow pattern and contaminate the measurements that are sensitive to a disruption of the flow pattern.
- High voltage pulsed signals having 10 ⁇ duration have been used to excite sound waves in an ultrasonic transducer attached to a curved delay line that conforms to the exterior curvature of a pipe, the sound waves being detected by a second transducer after traversing through the fluid in the pipe.
- the transit time of the pulses is measured by threshold detection of the received signal, which is difficult due to multiple reflections in the container wall and also due to propagation of sound through the wall itself.
- the average of 100 signals is required for proper threshold detection for a transit time measurement from which fluid sound speed and subsequently fluid composition are determined.
- Embodiments of the present invention overcome the disadvantages and limitations of the prior art by providing a noninvasive method for determining the composition of a fluid inside a pipe.
- the method for noninvasively determining the composition of a multiphase fluid comprising oil and water flowing through pipe having a wall and an outside surface including: generating an ultrasonic frequency chirp signal using a transmitting transducer in ultrasonic communication with the outside surface of the pipe; receiving the generated frequency chirp signal on a receiving transducer in ultrasonic communication with the outside surface of the pipe diametrically opposed to the transmitting transducer after the chirp signal passes through said multiphase fluid, wherein an electrical signal is generated in response thereto; receiving the electrical signal; dechirping the frequency chirp by multiplying the received signal and the generated frequency chirp signal and obtaining the difference frequency from which the total transit time of the frequency chirp signal is determined; determining the time delay of the frequency chirp signal in the wall of the pipe; and subtracting the time delay from the total transit time to determine the propagation time of
- the method for noninvasively determining the composition of a multiphase fluid comprising oil and water flowing through pipe having a wall and an outside surface includes: generating an ultrasonic frequency chirp signal using a transmitting transducer in ultrasonic communication with the outside surface of the pipe; receiving the generated frequency chirp signal on a receiving transducer in ultrasonic communication with the outside surface of the pipe diametrically opposed to the transmitting transducer after the chirp signal passes through the multiphase fluid, wherein an electrical signal is generated in response thereto; receiving the electrical signal; cross-correlating the transmitted signal with the received signal, wherein cross-correlation peaks are generated; selecting the highest peak which corresponds to the total transmit time of the frequency chirp signal; determining the time delay of the frequency chirp signal in the wall of the pipe; and subtracting the time delay from the total transit time to determine the propagation time of the frequency chirp signal through said multiphase fluid, from which
- the method for noninvasively determining the composition of a multiphase fluid comprising oil and water flowing through pipe having a wall, an outside surface, and an axis, hereof includes: generating an ultrasonic frequency chirp signal using a transmitting transducer in ultrasonic communication with the outside surface of the pipe; receiving the generated frequency chirp signal on a receiving transducer in ultrasonic communication with the outside surface of the pipe diametrically opposed to the transmitting transducer after the chirp signal passes through the multiphase fluid, wherein an electrical signal is generated in response thereto; receiving the electrical signal; cross-correlating the transmitted signal with the received signal, wherein cross-correlation peaks are generated; determining the time between consecutive peaks, wherein the determined time is twice the travel time through the multiphase fluid, from which the composition of the multiphase fluid is determined.
- the method for noninvasively determining the composition of a multiphase fluid comprising oil and water flowing through pipe having a wall and an outside surface includes: generating an ultrasonic frequency chirp signal having a duration shorter than the time the frequency chirp takes to pass through the multiphase fluid using a transmitting transducer in ultrasonic communication with the outside surface of the pipe; receiving the generated frequency chirp signal on a receiving transducer in ultrasonic communication with the outside surface of the pipe diametrically opposed to the transmitting transducer after the chirp signal passes through the multiphase fluid, wherein an electrical signal is generated in response thereto; receiving the electrical signal; transforming the electrical signal using a Short Time Fourier Transform, whereby a plot of the frequency variation of the received frequency chirp as a function of time is generated, amplitude modulations due to wall resonances appear as individual data points; and the generated frequency chirp is a straight line having a slope;
- Benefits and advantages of embodiments of the present invention include, but are not limited to, providing a noninvasive method for determining the composition of a fluid that can either be flowing or static inside a pipe while taking advantage of the pipe walls to assist the measurement rather than adversely effecting the measurement.
- composition determinations unaffected by the presence of the wall of the container or pipe high signal-to-noise ratio of the due to the use of a frequency chirp and methods for signal analysis that simultaneously use multiple methods for determining the sound speed in the fluid and are superior to conventional pulse time-of-flight methods, extraction of high-quality sound speed data even when the excitation chirp signal is not of high quality and may be square-wave based which simplifies the wave generation and allows lower power consumption electronics to be used.
- FIGURE 1A is a schematic representation of an embodiment of the measurement apparatus of the present invention effective for practicing the method hereof
- FIG. 1 B is a schematic representation of a perspective view of a pipe and a curved transducer affixed to the exterior surface thereof
- FIG. 1 C is a schematic representation of a top view of the pipe and curved transducers.
- FIGURE 2 is a graph of amplitude versus time illustrating data obtained using the apparatus shown in FIGS. 1A - 1 C, hereof, where the multiple burst characteristics are due to the transmission characteristics of the pipe wall.
- FIGURE 3A illustrates a typical chirp signal commencing at a low frequency, f-i , which is increased to a higher frequency, in a continuous manner over a time period T, while the frequency variation of the chirp as a function of time is shown in FIG. 3B.
- FIGURE 4A illustrates a generated chirp input signal, s(t), shown as a line which propagates through a system and is detected by a receiver after a certain delay, the delayed chirp signal being s(t-x) such that in a linear system is linear, the two signals are parallel lines and the delay time, ⁇ , is the sought transit time measurement, while FIG. 4B illustrates that the measurement may also be considered as the shift in frequency between the two chirp lines given by ⁇ , which is a fixed frequency, this difference frequency, Sdiff(t), called the de-chirped frequency, being constant during the period of overlap of the two signals, and equivalent to the delay time.
- FIGURE 5A shows the delayed chirp signal including a series of equally spaced chirps in time having decreasing amplitude and resulting from reflections inside the wall of the pipe or container, while FIG. 5B schematically illustrates a pulsed sound signal being multiply reflected as it traverses a wall.
- FIGURE 6A is a graph of the signal detected by the receiver transducer from a water-filled brass pipe
- FIG. 6B is a graph of the cross-correlation of this signal with the source signal from the transmitter transducer illustrating significant pulse compression
- FIGURES 7A and 7B are graphs showing the first chirp burst received by the receiver transducer without multiple echoes for a stainless steel and a brass pipe having identical dimensions, respectively, while FIGS. 7C and 7D illustrate corresponding Fast Fourier Transforms of these signals, respectively.
- FIGURES 8A and 8B show the same received chirp signals from a brass pipe containing water, with FIG. 8B being recorded over a sufficient time span that the effects of recording multiple echoes can be separated, while corresponding Fast Fourier Transforms of the signals for FIGS. 8A and 8B are illustrated in FIGS. 8C and 8D, respectively.
- FIGURE 9A shows the Fast Fourier Transform of received chirp signals, over a sufficient time period that effects due to recording multiple echoes for a brass pipe filled with water can be separated, as in FIG. 8D hereof, with a portion of the graph around 2.7 MHz being enclosed by a dashed oval curve, while FIG. 9B shows an expanded view of the emphasized portion of FIG. 9A illustrating the Fast Fourier Transform of peaks observed in the fluid between the two pipe walls.
- FIGURE 10 is a graph illustrating two parallel state lines shifted in time, the first line representing the transmitted chirp between 1 and 4 MHz and having 100 ⁇ duration starting at zero time, and the solid circles represent the peak positions in time and frequency of the various received wall peaks that modulate the sound transmission, with a least-squares fit made to this data, but constrained to the same slope as the transmitted chirp line being shown by the solid line, with the Fast Fourier Transform on the right of the graph being provided for comparison with the frequency transmission windows.
- FIGURE 11A is a graph of the Joint Time-Frequency Analysis of the product of the transmitted chirp and the received delayed chirp (FIGS. 4A and 4B) for a brass pipe containing water
- FIG. 11 B is a graph of the Fast Fourier Transform of the product of the transmitted chirp and the received delayed chirp.
- an embodiment of the present invention includes a method for noninvasively determining the composition of a fluid inside a pipe.
- the method includes exciting a first transducer located on the external surface of the pipe through which the fluid under investigation is flowing, to generate an ultrasound chirp signal, as opposed to conventional pulses.
- the chirp signal is received by a second transducer disposed on the external surface of the pipe opposing the location of the first transducer, from which the transit time through the fluid is determined and the sound speed of the ultrasound in the fluid is calculated.
- the composition of a fluid is calculated from the sound speed therein.
- the fluid density may also be derived from measurements of the sound attenuation.
- Chirp measurements permit high signal-to-noise ratios to be obtained, and lower power operation.
- the transducers may be directly attached to the pipe, and the transducer surface may have the same radius of curvature as the pipe. Such curved transducers do not require delay lines to obtain adequate signals.
- a digital signal processor (DSP) circuit may be used process the received chirp signal to provide the sound speed.
- DSP digital signal processor
- Embodiments of the present method can provide accurate transit time determinations that are not affected by the presence of a thick pipe wall, and may advantageously use the wall.
- the transit time through the wall is determined simultaneously with the transit time in the fluid inside the pipe or container.
- the curved transducers may mitigate the generation of guided wave modes through the pipe wall by suppressing the generation of such wave modes.
- Signal analysis procedures described in detail hereinbelow provide a robust transit time measurement which is not affected by random noise.
- the received signal propagates through both the wall of the pipe and the fluid inside the pipe.
- the signal can be rather noisy and it is not possible to determine the transit time by a simple threshold detection as conventionally done.
- five signal processing approaches may be used to extract the transit time information from the data with pipe wall effects having been subtracted.
- These signal analysis techniques include: (1 ) Joint Time-Frequency Analysis to obtain the propagation delay of each point of the chirp; (2) a de-chirping technique for providing a fixed frequency signal that is directly related to the chirp delay; (3) a cross-correlation technique that determines the transit time through the fluid and the multiple reflections through the fluid, and that provides sound attenuation information; (4) Fast Fourier transformation (FFT) of the received signal to obtain the interference spectrum of the sound signal in the fluid and in turn its sound speed; and (5) an FFT of the received signal to obtain the signal transmission through the wall and the wall resonance peaks that may be used for determining either the wall thickness or the transit time through the wall.
- FFT Fast Fourier transformation
- FIG. 1A a schematic representation of an embodiment of the measurement apparatus, 10, of the present invention effective for practicing the method hereof is illustrated.
- Microcontroller, 12, controls digital signal processor (DSP), 14, through universal serial bus (USB), 16.
- DSP 14 loads the chirp waveform into arbitrary waveform generator (WG), 18, which produces the linear chirp waveform to be directed to power amplifier, 20, for driving transmitting transducer, 22.
- WG arbitrary waveform generator
- Waveform generator 18 may generate any mathematically generated waveform and is not limited to producing linear frequency chirp.
- the chirp signal typically used is sinusoidal, but a square wave chirp can be used as well to reduce power consumption by the output amplifier and can also simplify the amplifier design. However, a square wave chirp signal produces higher harmonics that can affect the measurement accuracy unless properly taken care of in the data analysis.
- Apparatus 10 generates signals in a frequency range between about 100 kHz and approximately 10 MHz having amplitudes between about 1 mV and about 50 V. The chirp duration may be between approximately 1 ps and about 10 ms.
- Transmitting transducer 22 may be differentially driven through a transformer (not shown in FIG. 1A) to avoid difficulties with ground loops. Transmitting transducer 22 is placed in ultrasonic communication with wall, 24, of pipe or tube, 26, which may include attaching transducer 22 directly to the exterior of wall 24.
- Receiving transducer, 28, is disposed in ultrasonic communication, which may include direct attachment of transducer 28 to the exterior of wall 24, diametrically opposed to transmitting transducer 22.
- Signal generated by receiving transducer are amplified by signal amplifier, 30, having gains between approximately 10 and approximately 60 db before being digitized using 2-channel, 16-bit, 60 Mega samples/s digitizer, 32, having data storage memory.
- Receiver transducer 28 may be transformer coupled for providing a differential signal, which may be advantageous both for electrical safety and for reduction in ambient noise pick up.
- Signal amplifier 30 may be disposed on a circuit board for close positioning to transducer 28 and shielded within a metal case.
- the output from WG 18 may be simultaneously digitized by digitizer 32, and the two chirp signals directed to DSP 14 for analysis before displaying on screen after processing by microcontroller 12, or recorded in the memory of microcontroller 12.
- Thermometer element, 36 may be attached to pipe wall 24 for measuring the temperature of wall 24 during measurements.
- the signal from sensor 36 may be digitized by resistance temperature device (RTD) converter, 38, and directed to USB bus 40 for communication with microcontroller 12. Signals may be processed between approximately every 0.1 s and about 1 s, and stored in microcontroller 12 or displayed on screen 34. Arrow, 42, depicts direction of fluid flow in pipe 26.
- Transducers 22 and 28 may be made from piezoelectric (PZT) material and can withstand a temperature up to 250 °F. As stated hereinabove, such transducers can be shaped so as to conform to the outer radius of pipe 26. Stainless steel and brass pipes used to collect the data set forth hereinbelow had inner diameters, 44, of about 3 in. and wall 24 thicknesses of 0.25 in. Other materials may also be used. The size of each PZT element used was 1 cm x 2 cm and curved along the long axis as shown in FIG. 1 B, which shows a schematic representation of a perspective view of pipe 26 and curved transducer 22. FIGURE 1 C is a schematic representation of a top view of pipe 26 and curved transducers 22 and 28. Transducers 22 and 28 may be cemented to the exterior surface of wall 24 using high-temperature epoxy for extended use but other attachment means may also be used.
- PZT piezoelectric
- the center frequency of transducer elements 22 and 28 can vary between about 1.5 and about 5 MHz, depending on the particular application. For highly attenuating heavy oils a lower frequency is used than for fluids that have high water content for which the higher frequencies are used. For smaller pipe diameters and less attenuating fluids, the frequency can be as high as approximately 10 MHz, which is not a limitation of the electronics which can readily be modified to operate at 50 MHz.
- the outer sides, 46, and, 48, of each of elements 22 and 28, respectively are covered with a layer of tungsten-loaded epoxy.
- this also makes the transducers more robust.
- transducers 22 and 28 are coupled to the outer surface of pipe 26 with a thin layer of epoxy, and delay lines are not necessary. Such contact suppresses the generation of guided wave modes in the pipe wall and any complications due to the guided wave modes.
- the two transducers are positioned directly opposite of one another to obtain a strong signal, and to provide a well-defined sound beam pattern inside the pipe. Other relative transducer locations may be employed, but provide poorer signal response.
- FIGURE 2 is a graph of amplitude versus time illustrating data obtained using the apparatus shown in FIGS. 1A - 1 C hereof.
- the chirp duration was 100 ⁇
- the frequency range was between approximately 1 and about 4 MHz
- the excitation voltage was less than about 10 V peak-to-peak.
- the measurement was made in a water-filled stainless steel pipe having 3-inch inner diameter and 0.25 inch wall thickness.
- the multiple burst characteristics in FIG. 2 are due to the transmission characteristics of the pipe wall as a function of frequency, and will be discussed in greater detail hereinbelow.
- FIGURE 3A illustrates a typical chirp signal.
- a frequency chirp ranging from about 100 kHz to approximately 10 MHz having duration between approximately 10 ⁇ and 200 ⁇ may be used. The duration depends on the pathlength through fluid and may be longer for larger pathlengths.
- the chirp signal starts at a low frequency, f-i , which is increased to a higher frequency, f 2 , in a continuous manner over a time period T.
- the frequency variation of the chirp as a function of time is shown in FIG. 3B.
- Chirp signals have several advantages.
- a chirp distributes the transmitted power for the measurement over a longer time period; therefore, high voltage excitation, as used in conventional pulse measurements, is not required, and signal excitation levels less than about 10 V is sufficient for most measurements.
- FIGURES 4A and 4B are schematic representations of chirp signal analyses.
- a generated chirp input signal s(t) is shown as a line having an angle (see FIG. 3B).
- This signal propagates through a system (for example, a water- filled pipe) and is detected by a receiver (output) after a certain delay, the delayed chirp signal being s(t-x).
- the system is linear, the two signals are parallel lines and the delay time, t, is the sought transit time measurement.
- the measurement may also be considered as the shift in frequency between the two chirp lines as given by ⁇ , which is a fixed frequency.
- This difference frequency, S d i f t), called the de- chirped frequency and illustrated in FIG. 4B, is a fixed frequency during the period of overlap of the two signals, and is equivalent to the delay time ⁇ . This is because a fixed time difference between two linear chirped signals gives a fixed frequency signal as each instance of one bhirp is shifted by the same amount in frequency from the other. The shift in time is thus linearly related to the shift in frequency and, therefore, a measurement of frequency shift provides a measure of time delay.
- An advantage is that the measurement is determined over the entire region of the frequency overlap of the two chirps and thus an averaged value is obtained.
- the frequency spectrum of the de-chirped signal will contain a single peak at ⁇ and a linearly increasing section that starts at Note that any additional reflections within the pipe walls will manifest as other distinct peaks at frequencies ⁇ ( ⁇ ⁇ ⁇ £ " ), where Td is the wall delay for each of the 'n' reflections.
- the first peak frequency of the de-chirped sinusoid is proportional to ⁇ . Therefore, the de-chirping process comprises a differential multiplication between chirp signal and delayed chirp signal, which is a frequency mixing process yielding a fixed difference frequency and a time-variant sum frequency.
- the time delay, ⁇ , between two chirp signals can be converted to a frequency signal ( ⁇ ) by the de- chirping process.
- FIGURE 5A shows the effect of the pipe or container wall on the measurements.
- the delayed chirp signal is observed with a series of equally spaced chirps in time having decreasing amplitude.
- FIGURE 5B schematically illustrates a pulsed sound signal being multiply reflected as it traverses a wall, where only one wall is shown for illustrative purposes. The transit time through the wall is ⁇ 0 and each reflection adds an additional time delay of 2 ⁇ 0 . Since each signal pass is affected by the acoustic impedance mismatch between the fluid and the wall material, consecutive reflections are reduced in amplitude, which includes information on fluid density if the acoustic impedance of the wall is known and from which fluid density may be determined.
- FIGURE 6A is a graph of the signal detected by the receiver transducer from a water-filled brass pipe. Cross-correlation of this signal with the source signal from the transmitter transducer is shown in FIG. 6B, and illustrates significant pulse compression. It is straightforward to determine the time corresponding to first highest peak which corresponds to the total transit time through both walls ( ⁇ 0 ) and through the fluid ( ⁇ ). The time between any two consecutive peaks in FIG. 6B is predicted to be twice the time it takes the pulse to travel through the fluid (2 ⁇ ) since the transit time through the walls is canceled in the difference. Thus, wall effects are removed, and an accurate measurement of the transit time through the fluid may be obtained.
- the sound speed can be easily determined from the ratio D/ ⁇ .
- the height of the peaks from multiple reflections (transits through the fluid) may be used to extract the sound attenuation in the fluid.
- the de-chirping method appears to be more immune to the amplitude variation of the chirp signal. For example, a square-wave chirp produces as well defined a de- chirped signal as the sine wave chirp produces.
- the quality of the result is degraded, because a square-wave consists of many higher harmonics.
- FIGURES 7A and 7B are graphs showing the first chirp burst received by the receiver transducer without the multiple echoes for a stainless steel and a brass pipe having identical dimensions, respectively, while FIGS. 7B and 7D show corresponding fast Fourier Transforms (FFTs) for these signals, respectively.
- FFTs fast Fourier Transforms
- the FFTs show multiple peaks within the 1-4 MHz range of the frequency chirp, and are the thickness mode resonances of the wall which determine the sound transmission characteristics of the wall. The peaks are equally spaced in frequency (AF W ).
- the sound speed of the wall material and the wall thickness, d are related through this difference frequency as:
- FIGURES 8A - 8D show the effect of including multiple echoes in the reduction of the data.
- FIGURES 8A and 8B show the same received chirp signals for a brass pipe filled with water (Multiple echoes received by the receiver transducer imply that the signal has bounced back and forth through the liquid several times, and has had time to set up resonances, after which liquid resonances superimposed on the wall resonances are observed), with FIG. 8B being recorded over a sufficient time span that the effects due to recording multiple echoes can be separated from the wall effects.
- the corresponding FFTs of the signals for FIGS. 8A and 8B are illustrated in FIGS. 8C and 8D, respectively.
- FIG. 8A the sound has propagated only once through the pipe diameter and therefore no fluid resonances due to multiple reflections have been generated.
- the FFT in FIG. 8C principally illustrates the effect of the wall and attenuation due to the fluid. Fluid attenuation is reflected in the peak widths.
- FIG. 8B multiple reflections are included and the FFT now shows the resonances being set up in the fluid between the two transducers.
- FIG. 9A The liquid resonances can be separately studied from the wall resonances as illustrated in FIG. 9A where the FFT of received chirp signals, over a sufficient time period that permits recording multiple echoes for a brass pipe filled with water is shown.
- the wall resonance peaks are observed in FIG. 9A and the frequency difference between two neighboring walls peaks is displayed as AF W .
- the liquid resonance peaks appear as noise on this frequency scale and therefore a small region needs to be expanded to observe these resonances more clearly.
- FIGURES 8D and 9A are the same.
- FIGURE 9B shows an expanded portion of the graph around 2.7 MHz in FIG. 9A that is enclosed with a dashed oval. A series of equally spaced peaks in frequency with a frequency spacing of AF L .
- the sound speed in fluid is given by:
- JTFA Joint Time-Frequency Analysis
- FIG. 10 The Joint Time-Frequency Analysis (JTFA) of received chirped data is shown in FIG. 10 hereof.
- the FFT of the received signal is shown on the right-hand side of the graph, which illustrates two parallel state lines shifted in time, the first line representing the transmitted chirp between 1 and 4 MHz and having 100 s duration starting at zero time.
- the solid circles represent the peak positions in time and frequency of the various received wall peaks that modulate the sound transmission, each subsequent frequency peak arriving at a later time.
- a least squares fit made to this data, but constrained to the same slope as the transmitted chirp line is shown by the solid line.
- the intercept of this line at 1 MHz (chirp start frequency) on the time axis is the total transit time.
- a continuous wavelet transform or other mathematical transform may be used to convert the data to time-frequency. This is a straightforward way to obtain the transit time from which the sound speed can be determined.
- FIGURE 1 1 illustrates the de-chirping technique described in FIGS. 4A and 4B and mathematically expressed in Eq. (4).
- the data shown in FIG. 1 1 is for a brass pipe containing water.
- the product of the source and received chirps are taken. If the delay is too great, such that there is no overlap or no significant overlap between the two signals, then one of the signals is translated in time until there is a reasonable degree (In the present situation, the duration of the chirp signal used is typically 100 ⁇ , whereas the actual transmit time through the pipe and the liquid inside is approximately 50 ⁇ xs. Therefore, if the transmitted and received signals are plotted in time from time zero and one signal is placed above the other one, there will be an overlap of the two signals.
- the final 50 ⁇ of the transmit signal will overlap with the first 50 ⁇ of the received signal.
- This kind of overlap is not always possible as in larger diameter pipes where the transmit time through the pipe may be longer than the duration of the transmit signal when the two signals will not overlap at all in time or overlap minimally.
- a certain amount of known delay time may be added to the transmit signal and shift it mathematically to make the two signals overlap better.
- the added time shift may be considered) of overlap, and the time shift is recorded for correcting the time.) of overlap, and the time shift is recorded for correcting the time.
- FIGURE 1 1A shows the JTFA of the product data without any time shift since the two signals sufficiently overlapped (almost 50%). As predicted by Eq.
- a fixed frequency is observed along with another, higher frequency component that varies with time.
- the fixed frequency de-chirped signal is of interest, and an average of all the peak values across the horizontal line provides the de-chirped frequency.
- an FFT of the product is performed, which is illustrated in the plot shown FIG. 11B.
- the first peak in this case is the de- chirp frequency, and since the bandwidth and the duration of the chirp are known, the delay time can be obtained from the chirp rate and the frequency (FIGS. 4A and 4B, and Eq. 4). It is to be noted that the lowest frequency peak near 1.6 MHz has satellite peaks, which are due to multiple reflections in the wall as discussed in FIGS. 5A and 5B.
- Eqs. 7 and 8 are least-squares polynomial fits to experimental data of sound speed for crude oil (c 0 ) and process water (c w ) in m/s as a function of temperature, T, in °C.
- measured density (p) of a mixture of oil and water can be represented by a linear rule-of-mixtures in terms of the density of crude oil (p 0 ) and process water (Pw) approach as follows:
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Biochemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Acoustics & Sound (AREA)
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Fluid Mechanics (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP11822784.2A EP2612115A4 (en) | 2010-09-03 | 2011-09-06 | Method for noninvasive determination of acoustic properties of fluids inside pipes |
KR1020137008465A KR101844098B1 (en) | 2010-09-03 | 2011-09-06 | Method for noninvasive determination of acoustic properties of fluids inside pipes |
AU2011295676A AU2011295676B2 (en) | 2010-09-03 | 2011-09-06 | Method for noninvasive determination of acoustic properties of fluids inside pipes |
BR112013004991A BR112013004991A2 (en) | 2010-09-03 | 2011-09-06 | method for noninvasively determining the composition of a multiphase fluid |
CN201180051477.7A CN103189719B (en) | 2010-09-03 | 2011-09-06 | For the method for the acoustic characteristic of the fluid of non-intrusion type determination pipe interior |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US37989810P | 2010-09-03 | 2010-09-03 | |
US61/379,898 | 2010-09-03 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2012031305A1 true WO2012031305A1 (en) | 2012-03-08 |
Family
ID=45769668
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2011/050583 WO2012031305A1 (en) | 2010-09-03 | 2011-09-06 | Method for noninvasive determination of acoustic properties of fluids inside pipes |
Country Status (7)
Country | Link |
---|---|
US (1) | US9404890B2 (en) |
EP (1) | EP2612115A4 (en) |
KR (1) | KR101844098B1 (en) |
CN (1) | CN103189719B (en) |
AU (1) | AU2011295676B2 (en) |
BR (1) | BR112013004991A2 (en) |
WO (1) | WO2012031305A1 (en) |
Families Citing this family (55)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8676904B2 (en) | 2008-10-02 | 2014-03-18 | Apple Inc. | Electronic devices with voice command and contextual data processing capabilities |
US8844359B2 (en) * | 2010-12-03 | 2014-09-30 | Hema-Q, Inc. | Apparatus for noninvasive measurement of properties of a fluid flowing in a tubing having a smaller inner diameter passage |
EP3809407A1 (en) | 2013-02-07 | 2021-04-21 | Apple Inc. | Voice trigger for a digital assistant |
GB2511739B (en) * | 2013-03-11 | 2018-11-21 | Zenith Oilfield Tech Limited | Multi-component fluid determination in a well bore |
US10168305B2 (en) * | 2013-10-17 | 2019-01-01 | Battelle Memorial Institute | Container screening system and method |
US9360377B2 (en) * | 2013-12-26 | 2016-06-07 | Rosemount Inc. | Non-intrusive temperature measurement assembly |
US9383238B2 (en) | 2014-02-19 | 2016-07-05 | Chevron U.S.A. Inc. | Apparatus, system and process for characterizing multiphase fluids in a fluid flow stream |
US10724968B2 (en) | 2014-03-21 | 2020-07-28 | Battelle Memorial Institute | System and method for solution constituent and concentration identification |
JP2015215171A (en) * | 2014-05-07 | 2015-12-03 | アズビル株式会社 | Ultrasonic flow meter and abnormality determination method for ultrasonic absorber |
US10170123B2 (en) | 2014-05-30 | 2019-01-01 | Apple Inc. | Intelligent assistant for home automation |
US9338493B2 (en) * | 2014-06-30 | 2016-05-10 | Apple Inc. | Intelligent automated assistant for TV user interactions |
KR101533539B1 (en) * | 2014-12-17 | 2015-07-03 | 성균관대학교산학협력단 | Method and apparatus for remotely idendifyiing fluid materials in pipe object |
DE102015102200B4 (en) * | 2015-02-16 | 2022-08-11 | Endress+Hauser Flow Deutschland Ag | Method for determining properties of a medium and device for determining properties of a medium |
WO2016161459A1 (en) * | 2015-04-02 | 2016-10-06 | Los Alamos National Security, Llc | Acoustic gas volume fraction measurement in a multiphase flowing liquid |
DE102015107752A1 (en) * | 2015-05-18 | 2016-11-24 | Endress + Hauser Flowtec Ag | Method for determining at least one tube wall resonance frequency and clamp-on ultrasonic flowmeter |
DE102015107750A1 (en) * | 2015-05-18 | 2016-11-24 | Endress + Hauser Flowtec Ag | Measuring system for measuring at least one parameter of a fluid |
WO2017005268A1 (en) * | 2015-07-03 | 2017-01-12 | Kamstrup A/S | Turbidity sensor based on ultrasound measurements |
US10585069B2 (en) | 2015-08-12 | 2020-03-10 | Chevron U.S.A. Inc. | Detection, monitoring, and determination of location of changes in metallic structures using multimode acoustic signals |
JP6788163B2 (en) * | 2015-08-12 | 2020-11-25 | トライアド ナショナル セキュリティー、エルエルシー | Detection and monitoring of changes in metal structures using multimode acoustic signals |
US10996203B2 (en) | 2015-08-12 | 2021-05-04 | Triad National Security, Llc | Detection, monitoring, and determination of location of changes in metallic structures using multimode acoustic signals |
US10747498B2 (en) | 2015-09-08 | 2020-08-18 | Apple Inc. | Zero latency digital assistant |
US10691473B2 (en) | 2015-11-06 | 2020-06-23 | Apple Inc. | Intelligent automated assistant in a messaging environment |
DK201670540A1 (en) | 2016-06-11 | 2018-01-08 | Apple Inc | Application integration with a digital assistant |
US11474073B2 (en) * | 2016-07-20 | 2022-10-18 | Triad National Security, Llc | Noninvasive acoustical property measurement of fluids |
JP6832152B2 (en) * | 2016-12-21 | 2021-02-24 | 上田日本無線株式会社 | Gas concentration measuring device and its calibration method |
US10605789B2 (en) | 2017-02-23 | 2020-03-31 | Southern Research Institute | Ultrasonic inspection system employing spectral and time domain processing of ultrasonic signal |
US10830735B2 (en) * | 2017-03-20 | 2020-11-10 | Triad National Security, Llc | Simultaneous real-time measurement of composition, flow, attenuation, density, and pipe-wallthickness in multiphase fluids |
DK180048B1 (en) | 2017-05-11 | 2020-02-04 | Apple Inc. | MAINTAINING THE DATA PROTECTION OF PERSONAL INFORMATION |
DK201770429A1 (en) | 2017-05-12 | 2018-12-14 | Apple Inc. | Low-latency intelligent automated assistant |
US20210140809A1 (en) * | 2017-06-02 | 2021-05-13 | Inventrom Private Limited | System and method for monitoring level of material stored in receptacles |
AT520557B1 (en) * | 2018-01-24 | 2019-05-15 | Anton Paar Gmbh | Method for determining a corrected value for the viscosity-dependent speed of sound in a fluid to be examined |
US10962393B2 (en) * | 2018-03-01 | 2021-03-30 | Saudi Arabian Oil Company | Multiphase flow rate measurement with elliptical ultrasonic transceiver array |
EP3785027A4 (en) * | 2018-04-27 | 2021-12-29 | Chevron U.S.A. Inc. | Detection, monitoring, and determination of location of changes in metallic structures using multimode acoustic signals |
US10928918B2 (en) | 2018-05-07 | 2021-02-23 | Apple Inc. | Raise to speak |
US11145294B2 (en) | 2018-05-07 | 2021-10-12 | Apple Inc. | Intelligent automated assistant for delivering content from user experiences |
DK180639B1 (en) | 2018-06-01 | 2021-11-04 | Apple Inc | DISABILITY OF ATTENTION-ATTENTIVE VIRTUAL ASSISTANT |
NO344122B1 (en) * | 2018-09-20 | 2019-09-09 | 4Subsea As | Flooded Member Detection by means of ultrasound |
US11462215B2 (en) | 2018-09-28 | 2022-10-04 | Apple Inc. | Multi-modal inputs for voice commands |
CN109283357A (en) * | 2018-11-15 | 2019-01-29 | 长沙理工大学 | A kind of Buchholz relay oil flow rate quantization method based on transformer insulated oil temperature and pressure |
US11348573B2 (en) | 2019-03-18 | 2022-05-31 | Apple Inc. | Multimodality in digital assistant systems |
WO2020186473A1 (en) * | 2019-03-20 | 2020-09-24 | 深圳市汇顶科技股份有限公司 | Time of flight generation circuit, and related chip, flow meter, and method |
DK201970509A1 (en) | 2019-05-06 | 2021-01-15 | Apple Inc | Spoken notifications |
US11307752B2 (en) | 2019-05-06 | 2022-04-19 | Apple Inc. | User configurable task triggers |
US11140099B2 (en) | 2019-05-21 | 2021-10-05 | Apple Inc. | Providing message response suggestions |
US10746716B1 (en) | 2019-05-31 | 2020-08-18 | Battelle Memorial Institute | System and method for solution constituent and concentration identification |
US11468890B2 (en) | 2019-06-01 | 2022-10-11 | Apple Inc. | Methods and user interfaces for voice-based control of electronic devices |
US11567038B2 (en) * | 2019-09-26 | 2023-01-31 | Triad National Security, Llc | Apparatus and method for shaped waveform interrogation |
EP3822660A1 (en) * | 2019-11-13 | 2021-05-19 | ABB Schweiz AG | Integrity detection system for an ultrasound transducer |
DE102019132483B3 (en) * | 2019-11-14 | 2020-12-03 | Elmos Semiconductor Se | Optimized signal shaping of chirp signals for automotive ultrasonic measuring systems with maximization of the sound emission duration at transducer resonance frequency |
US11061543B1 (en) | 2020-05-11 | 2021-07-13 | Apple Inc. | Providing relevant data items based on context |
US11490204B2 (en) | 2020-07-20 | 2022-11-01 | Apple Inc. | Multi-device audio adjustment coordination |
US11438683B2 (en) | 2020-07-21 | 2022-09-06 | Apple Inc. | User identification using headphones |
WO2022272054A1 (en) * | 2021-06-24 | 2022-12-29 | Triad National Security, Llc | Method of detecting wear and tear in a rotating object |
JP2023072292A (en) * | 2021-11-12 | 2023-05-24 | 日清紡ホールディングス株式会社 | Waveform shaping device and gas concentration measuring device |
KR102586523B1 (en) * | 2023-05-04 | 2023-10-10 | (주) 우리전자통신 | Real-time detection system of closed tube damage attempts |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040168523A1 (en) * | 2002-11-12 | 2004-09-02 | Fernald Mark R. | Apparatus having an array of piezoelectric film sensors for measuring parameters of a process flow within a pipe |
US20050125166A1 (en) * | 2003-10-09 | 2005-06-09 | Loose Douglas H. | Method and apparatus for measuring a parameter of a fluid flowing within a pipe using an array of sensors |
US20050215902A1 (en) * | 2002-05-06 | 2005-09-29 | Greenwood Margaret S | System and technique for characterizing fluids using ultrasonic diffraction grating spectroscopy |
US20090078049A1 (en) * | 2007-09-25 | 2009-03-26 | The Regents Of The University Of California | Non-contact feature detection using ultrasonic lamb waves |
US20090241672A1 (en) * | 2008-03-26 | 2009-10-01 | Gysling Daniel L | System and Method for Providing a Compositional Measurement of a Mixture Having Entrained Gas |
US7775086B2 (en) * | 2006-09-01 | 2010-08-17 | Ut-Battelle, Llc | Band excitation method applicable to scanning probe microscopy |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA1206582A (en) * | 1983-03-25 | 1986-06-24 | Carl Dodge | Acoustic caliper tool |
US5117698A (en) * | 1988-12-07 | 1992-06-02 | Joseph Baumoel | Pulse train detection in transit time flowmeter |
US6227040B1 (en) * | 1998-02-03 | 2001-05-08 | Caldon, Inc. | Method and apparatus for determining the viscosity of a fluid in a container |
SE516979C2 (en) | 2000-07-14 | 2002-03-26 | Abb Ab | Active acoustic spectroscopy |
JP4169504B2 (en) * | 2001-10-26 | 2008-10-22 | 東京電力株式会社 | Doppler type ultrasonic flowmeter |
NL1020714C2 (en) * | 2002-05-30 | 2003-12-02 | Tno | Ultrasonic characterization of high concentration particles. |
US6644119B1 (en) * | 2002-06-28 | 2003-11-11 | The Regents Of The University Of California | Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry |
US6837098B2 (en) * | 2003-03-19 | 2005-01-04 | Weatherford/Lamb, Inc. | Sand monitoring within wells using acoustic arrays |
JP2008512653A (en) * | 2004-09-03 | 2008-04-24 | ネフロス・インコーポレーテッド | Doppler flow velocity measuring device |
US7526966B2 (en) * | 2005-05-27 | 2009-05-05 | Expro Meters, Inc. | Apparatus and method for measuring a parameter of a multiphase flow |
US7503217B2 (en) * | 2006-01-27 | 2009-03-17 | Weatherford/Lamb, Inc. | Sonar sand detection |
NO345532B1 (en) * | 2006-11-09 | 2021-03-29 | Expro Meters Inc | Apparatus and method for measuring a fluid flow parameter within an internal passage in an elongate body |
US8141434B2 (en) * | 2009-12-21 | 2012-03-27 | Tecom As | Flow measuring apparatus |
-
2011
- 2011-09-06 BR BR112013004991A patent/BR112013004991A2/en not_active IP Right Cessation
- 2011-09-06 KR KR1020137008465A patent/KR101844098B1/en active IP Right Grant
- 2011-09-06 CN CN201180051477.7A patent/CN103189719B/en not_active Expired - Fee Related
- 2011-09-06 EP EP11822784.2A patent/EP2612115A4/en not_active Withdrawn
- 2011-09-06 WO PCT/US2011/050583 patent/WO2012031305A1/en active Application Filing
- 2011-09-06 US US13/226,444 patent/US9404890B2/en active Active
- 2011-09-06 AU AU2011295676A patent/AU2011295676B2/en not_active Ceased
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050215902A1 (en) * | 2002-05-06 | 2005-09-29 | Greenwood Margaret S | System and technique for characterizing fluids using ultrasonic diffraction grating spectroscopy |
US20040168523A1 (en) * | 2002-11-12 | 2004-09-02 | Fernald Mark R. | Apparatus having an array of piezoelectric film sensors for measuring parameters of a process flow within a pipe |
US20050125166A1 (en) * | 2003-10-09 | 2005-06-09 | Loose Douglas H. | Method and apparatus for measuring a parameter of a fluid flowing within a pipe using an array of sensors |
US7775086B2 (en) * | 2006-09-01 | 2010-08-17 | Ut-Battelle, Llc | Band excitation method applicable to scanning probe microscopy |
US20090078049A1 (en) * | 2007-09-25 | 2009-03-26 | The Regents Of The University Of California | Non-contact feature detection using ultrasonic lamb waves |
US20090241672A1 (en) * | 2008-03-26 | 2009-10-01 | Gysling Daniel L | System and Method for Providing a Compositional Measurement of a Mixture Having Entrained Gas |
Non-Patent Citations (1)
Title |
---|
See also references of EP2612115A4 * |
Also Published As
Publication number | Publication date |
---|---|
KR20130102580A (en) | 2013-09-17 |
KR101844098B1 (en) | 2018-03-30 |
US9404890B2 (en) | 2016-08-02 |
EP2612115A4 (en) | 2017-05-17 |
CN103189719B (en) | 2016-03-16 |
AU2011295676A1 (en) | 2013-03-21 |
CN103189719A (en) | 2013-07-03 |
BR112013004991A2 (en) | 2016-05-31 |
EP2612115A1 (en) | 2013-07-10 |
US20120055253A1 (en) | 2012-03-08 |
AU2011295676B2 (en) | 2015-10-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9404890B2 (en) | Method for noninvasive determination of acoustic properties of fluids inside pipes | |
US8820147B2 (en) | Multiphase fluid characterization system | |
JP4535872B2 (en) | Non-invasive characterization of flowing multiphase fluids using ultrasonic interferometry | |
US11474073B2 (en) | Noninvasive acoustical property measurement of fluids | |
US10908131B2 (en) | Acoustic gas volume fraction measurement in a multiphase flowing liquid | |
US20020166383A1 (en) | Method and apparatus for pulsed ultrasonic doppler measurement of wall deposition | |
US20200088686A1 (en) | Simultaneous real-time measurement of composition, flow, attenuation, density, and pipe-wallthickness in multiphase fluids | |
US11808737B2 (en) | Ultrasonic system and method for non-intrusive detection and measurement of impurities in multiphase flows | |
JP2007309794A (en) | Apparatus and method for measuring plate thickness | |
EP2069723B1 (en) | Apparatus for attenuating acoustic waves propagating within a pipe wall | |
RU2532143C1 (en) | Method of determination of nonlinear ultrasonic parameter of liquids and device for its implementation | |
RU2189016C1 (en) | Method of continuous ultrasonic monitoring of level of liquid media in technological reservoirs | |
Salvi et al. | A continuous-wave method for sound speed measurement based on an infinite-echo model | |
Tucker et al. | Prototype instrument for noninvasive ultrasonic inspection and identification of fluids in sealed containers |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201180051477.7 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11822784 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2011295676 Country of ref document: AU Date of ref document: 20110906 Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2011822784 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 20137008465 Country of ref document: KR Kind code of ref document: A |
|
REG | Reference to national code |
Ref country code: BR Ref legal event code: B01A Ref document number: 112013004991 Country of ref document: BR |
|
ENP | Entry into the national phase |
Ref document number: 112013004991 Country of ref document: BR Kind code of ref document: A2 Effective date: 20130228 |