Primary reciprocity-based method for calibration of hydrophone magnitude and phase sensitivity: Complete tests at frequencies from 1 to 7MHz

Oliveira, Everande Gobira de; Costa-Félix, Rodrigo Pereira Barretto da; Machado, João Carlos

doi:10.1016/j.ultras.2014.12.006

Cited by 10 publications

(5 citation statements)

References 29 publications

(47 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Complex sensitivities for the three needle hydrophones were measured using a digital time-delay spectrometry (TDS) system previously described [27, 53]. (There are many methods for measuring sensitivity magnitude but fewer methods for measuring sensitivity phase [53–57], with some TDS methods extending to frequencies as high as 40 MHz [27, 56] and a nonlinear method providing phase measurements at harmonic frequencies up to 100 MHz [55] Some methods have shown that common hydrophone measurement systems can be accurately modeled as minimum phase systems [27, 53, 56]. ) A PVDF membrane hydrophone (HMB-200, Onda Corp., Sunnyvale, CA) was used for a reference in substitution experiments.…”

Section: Experimental Methodsmentioning

confidence: 99%

Pressure Pulse Distortion by Needle and Fiber-Optic Hydrophones due to Nonuniform Sensitivity

Wear

Liu

Harris

2018

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

View full text Add to dashboard Cite

Needle and fiber optic hydrophones have frequency-dependent sensitivity, which can result in substantial distortion of nonlinear or broadband pressure pulses. A rigid cylinder model for needle and fiber optic hydrophones was used to predict this distortion. The model was compared with measurements of complex sensitivity for a fiber optic hydrophone and 3 needle hydrophones with sensitive element sizes (d) of 100, 200, 400, and 600 μm. Theoretical and experimental sensitivities agreed to within 12 ± 3% (RMS normalized magnitude ratio) and 8 ± 3 degrees (RMS phase difference) for the four hydrophones over the range from 1 – 10 MHz. The model predicts that distortions in peak positive pressure can exceed 20% when d/λ0 < 0.5 and SI > 7% and can exceed 40% when d/λ0 < 0.5 and SI > 14%, where λ0 is the wavelength of the fundamental component and SI (spectral index) is the fraction of power spectral density contained in harmonics. The model predicts that distortions in peak negative pressure can exceed 15% when d/λ0 < 1. Measurements of pulse distortion using a 2.25 MHz source and needle hydrophones with d = 200, 400 and 600 μm agreed with the model to within a few percent on the average for SI values up to 14%. This work 1) identifies conditions for which needle and fiber optic hydrophones produce substantial distortions in acoustic pressure pulse measurements and 2) offers a practical deconvolution method to suppress these distortions.

show abstract

Section: Experimental Methodsmentioning

confidence: 99%

Pressure Pulse Distortion by Needle and Fiber-Optic Hydrophones due to Nonuniform Sensitivity

Wear

Liu

Harris

2018

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

View full text Add to dashboard Cite

show abstract

“…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.

View full text Add to dashboard Cite

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.

show abstract

“…Ultrasound has been demonstrated to be useful to cell culture treatment [79], as well. In all cases, a proper evaluation of ultrasonic parameters or transducer characteristics plays an important role, and some basic metrological procedures shall be followed, including uncertainty determination [80][81][82][83].…”

Section: The Futurementioning

confidence: 99%

Ultrasound Methods for Biodiesel Production and Analysis

Oliveira¹,

Baêsso²,

Moraes³

et al. 2018

Biofuels - State of Development

View full text Add to dashboard Cite

Ultrasonic techniques have been widely used in biodiesel production, since the acoustic cavitation is a phenomenon capable of accelerating potentially the transesterification reactions. The equipment employed in such approach was simply equipment available in any regular laboratory of chemistry. Further developments introduced the ultrasound as an important tool to produce biodiesel. The main advantage is increasing the conversion of esters at reduced reaction times, with significantly lower production costs. As a method for characterization and analysis of materials, ultrasound has been used since several decades ago. However, ultrasonic analytical methods based on metrological principles are fairly recent investigated. Using ultrasound as physical principle to interrogate biodiesel is a promising field of research, with some remarkable outcomes produced so far. The aim of this chapter is to demonstrate advances of using ultrasonic techniques in production and characterization of biodiesel, as well as an appraisal of the current technology status, and provide insights into future developments.

show abstract

Primary reciprocity-based method for calibration of hydrophone magnitude and phase sensitivity: Complete tests at frequencies from 1 to 7MHz

Cited by 10 publications

References 29 publications

Pressure Pulse Distortion by Needle and Fiber-Optic Hydrophones due to Nonuniform Sensitivity

Pressure Pulse Distortion by Needle and Fiber-Optic Hydrophones due to Nonuniform Sensitivity

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

Ultrasound Methods for Biodiesel Production and Analysis

Contact Info

Product

Resources

About