Absolute Hydrophone Calibration to 40 MHz Using Ultrasonic Far-Field

Matsuda, Youichi; Yoshioka, Masahiro; Uchida, Takeyoshi

doi:10.2320/matertrans.i-m2014814

Cited by 13 publications

(11 citation statements)

References 4 publications

(2 reference statements)

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“…Although many researchers have conducted a large number of studies on the propagation characteristics of Lamb waves and liquid-level detection applications using Lamb waves, it is difficult to find specific research results on internal wedge parameters in making Lamb wave sensors. The wedge is an essential component in the Lamb wave sensor, as it can act as a buffer block to avoid the near-field area [21]. Liu et al [22] compared the materials of the buffer block in detail and drew the curve of the sound velocity with frequency and temperature in PMMA.…”

Section: Introductionmentioning

confidence: 99%

Impact of Wedge Parameters on Ultrasonic Lamb Wave Liquid-Level Sensor

Xue

Gao

Liu

et al. 2022

Sensors

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The ultrasonic Lamb wave detection principle can realize the noncontact measurement of liquid level in closed containers. When designing an ultrasonic Lamb wave sensor, it is vital to thoroughly study and select the optimal wedge size at the front of the sensor. In this paper, firstly, we select the best working mode of Lamb waves according to their propagation dispersion curve in aluminum alloy, and we obtain the best angle of wedge through experiments. Secondly, we study the impact of the size of the wedge block on the results, and we obtain the selection method of wedge block parameters. The evaluations show that, when the frequency–thickness product is 3 MHz·mm, the Lamb waves work in the A1 mode, and the experimental effect is the best. At this time, the incident angle of the ultrasonic wave is 27.39°. The wedge thickness should be designed to avoid the near-field area of the ultrasonic field, and we should choose the length as odd multiples of 1/4 wavelength. The rules obtained from the experiment can effectively select the best working mode for ultrasonic Lamb waves, while also providing a basis for the design of the wedge block size in a Lamb wave sensor.

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Section: Introductionmentioning

confidence: 99%

Impact of Wedge Parameters on Ultrasonic Lamb Wave Liquid-Level Sensor

Xue

Gao

Liu

et al. 2022

Sensors

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“…Similar to PTB, NPL's new interferometer is based on a 600 MHz bandwidth laser vibrometer together with the lasergenerated ultrasound source will be evaluated in extending its traceable frequency range from its current upper limit of 60 MHz. NMI-China and NMI-Japan have also extended their primary standards based on optical interferometry up to at least 40 MHz [19], [20], [26]. Taking into consideration of the latest development across NMIs there will be a need to extend the frequency range of future Key Comparisons, underpinned by the availability of high quality, stable reference hydrophones.…”

Section: Discussionmentioning

confidence: 99%

“…Various techniques have been explored for calibrating hydrophones [6], [18], [21], [26]- [28]. Optical interferometers are capable of measuring broadband and finite amplitude distorted ultrasound fields several megapascals in amplitude.…”

Section: Realizing the Acoustic Pascalmentioning

confidence: 99%

Dissemination of the Acoustic Pascal: The Role and Experiences of a National Metrology Institute

Rajagopal

Silva

Miloro

et al. 2023

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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Hydrophones are pivotal measurement devices ensuring medical ultrasound acoustic exposures comply with the relevant national and international safety criteria. These devices have enabled the spatial and temporal distribution of key safety parameters to be determined in an objective and standardized way. Generally based on piezoelectric principles of operation, to convert generated voltage waveforms to acoustic pressure, they require calibration in terms of receive sensitivity, expressed in units of V•Pa −1 . Reliable hydrophone calibration with associated uncertainties plays a key role in underpinning a measurement framework that ensures exposure measurements are comparable and traceable to internationally agreed units, irrespective of where they are carried out globally. For well over three decades, the United Kingdom National Physical Laboratory (NPL) has provided calibrations to the user community covering the frequency range 0.1 -60 MHz, traceable to a primary realization of the acoustic pascal through optical interferometry. Typical uncertainties for sensitivity are 6% to 22% (for a coverage factor k = 2), degrading with frequency. The article specifically focusses on dissemination of the acoustic pascal through NPL's calibration services which are based on comparison with secondary standard hydrophones previously calibrated using the NPL primary standard. The work demonstrates the stability of the employed dissemination protocols by presenting representative calibration histories on a selection of commercially available hydrophones. Results re-affirm the guidance provided within international standards for regular calibration of a hydrophone in order to underpin measurement confidence. The process by which internationally agreed realizations of the acoustic pascal are compared and validated through Key Comparisons, is also described.

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“…We have developed techniques for the precise measurement of ultrasonic fields to evaluate the performance and safety of ultrasonic medical equipment and have provided related measurement standards. [1][2][3][4][5][6][7] In ultrasonic diagnosis, precise and practical measurement techniques are required for balancing patient safety during diagnosis 8,9) with improvement in diagnostic image brightness. 10) Therefore, a method based on the amplitude and phase frequency responses of hydrophone sensitivity, hereafter referred to as the deconvolution method, has been developed.…”

Section: Introductionmentioning

confidence: 99%

Improvement of extrapolating frequency response of hydrophone sensitivity using numerical simulation that includes assumptions about materials and construction of hydrophone for measuring instantaneous acoustic pressure of diagnostic ultrasound

Chiba

Umemura

Yoshioka

2022

Jpn. J. Appl. Phys.

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To evaluate the safety of diagnostic ultrasound, a precise and practical technique for measuring instantaneous acoustic pressure using the frequency response of hydrophone sensitivity has been investigated. We previously confirmed that the extrapolation of the frequency response using constants that are equal to extremes of the frequency range of certificated hydrophone sensitivities is generally effective when this frequency range is narrower than that from 0.5 to 8 times the center frequency of the measured ultrasound. However, this method is not always effective for hydrophones with large frequency response fluctuations. Here, we study whether the effectiveness of the extrapolation could be improved by using numerical simulation that includes assumptions about the materials and construction of the hydrophone and got the prospect that diagnostic ultrasound can be precisely measured using certificated sensitivity even if the upper frequency of certificated sensitivity is only up to twice the center frequency of the diagnostic ultrasound.

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Absolute Hydrophone Calibration to 40 MHz Using Ultrasonic Far-Field

Cited by 13 publications

References 4 publications

Impact of Wedge Parameters on Ultrasonic Lamb Wave Liquid-Level Sensor

Impact of Wedge Parameters on Ultrasonic Lamb Wave Liquid-Level Sensor

Dissemination of the Acoustic Pascal: The Role and Experiences of a National Metrology Institute

Improvement of extrapolating frequency response of hydrophone sensitivity using numerical simulation that includes assumptions about materials and construction of hydrophone for measuring instantaneous acoustic pressure of diagnostic ultrasound

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