A study on the pressure leakage correction of pistonphones at infrasonic frequencies

He, Wei; Zhang, Fan; He, Longbiao; Rong, Zuochao

doi:10.1016/j.jsv.2014.09.030

Cited by 13 publications

(3 citation statements)

References 13 publications

(23 reference statements)

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“…However, in reality, the chamber inside is in transition between adiabatic and isothermal states due to heat conduction from the chamber walls. This discrepancy was pointed out by He et al [23], and it remains a large uncertainty source. Recently, gapless pressure-generating ports, such as a membrane-sealing structure between the piston and chamber and a sealed loudspeaker have been proposed [17][18][19]21].…”

Section: Introductionmentioning

confidence: 89%

Investigation of sound pressure leakage effect for primary calibration down to 10⁻² Hz using a laser pistonphone system

Hirano,

Takahashi,

Yamada

et al. 2024

Meas. Sci. Technol.

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Recently, the demand for sensor calibration in the infrasonic range has increased to obtain accurate information when monitoring infrasound generated by large-scale natural disasters. The laser pistonphone method is a primary calibration method to evaluate infrasound sensors in the low-frequency range. The main concern with this method is that sound pressure leakage from an inherent gap significantly changes the acoustic transfer impedance of a pistonphone at lower frequencies. To apply the laser pistonphone method in the low-frequency range down to 10−2 Hz, it is essential to accurately evaluate and compensate for the leakage effect, i.e., the gap’s acoustic transfer impedance. In this study, we propose a technique for experimentally evaluating the gap impedance. The main idea is to determine the total acoustic transfer impedance by dividing the sound pressure by the volume velocity and then deducing the gap impedance by subtracting the chamber impedance from the obtained total acoustic transfer impedance. A digital pressure sensor was used to precisely measure sound pressure below 100 Hz because pressure sensors are suitable for accurate measurement of pressure fluctuations at low frequencies. We validated the proposed approach by calibrating an analog pressure sensor that outputs an analog voltage proportional to the absolute pressure. As a result, the sensitivity calibrated by the laser pistonphone method at 0.02 Hz agreed with the static sensitivity provided by the manufacturer within 0.02 dB.

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Section: Introductionmentioning

confidence: 89%

Investigation of sound pressure leakage effect for primary calibration down to 10⁻² Hz using a laser pistonphone system

Hirano,

Takahashi,

Yamada

et al. 2024

Meas. Sci. Technol.

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show abstract

“…The sealing is managed with this adjustment and without O-rings, therefore requiring corrections of leaks that appear at very low frequencies and limiting the operating range to approximately 1 Hz. The authors subsequently improved and characterized the device with a modification of the piston drive system and an analytical model for the leakage, which made it possible to operate at frequencies down to 0.001 Hz [34,35]. In 2016, the authors demonstrated the performance of the device by providing calibration equivalences with the pressure reciprocity method for amplitude sensitivities at frequencies down to 1 Hz [36].…”

Section: Overview Of Devices For Calibration Of Infrasound Sensorsmentioning

confidence: 99%

A laser pistonphone designed for absolute calibration of infrasound sensors from 10 mHz up to 20 Hz

et al. 2022

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There has been an increased demand for traceable calibrations at infrasonic frequencies in support of geophysical monitoring applications, an example being the Comprehensive nuclear Test Ban Treaty Organization, which provides a global international coverage for nuclear testing ban, and requires for the International Monitoring System. In this paper, a new laser pistonphone design is presented with the objective of establishing primary standards for sound pressure at very low frequencies down to 10~mHz. The piston is a modified accessorized loudspeaker driver whose diameter is equal to the diameter of the front pistonphone cavity. The volume velocity of the piston is measured through a laser interferometer and the current version was designed to have an upper frequency limit of 20 Hz, to overlap with the closed coupler reciprocity method of calibration. Particular attention has been given to the sealing to avoid the pressure leakage loss. The dimensions of the front cavity were designed to allow the calibration of a large variety of sensors, including microphones, barometers, manometers and microbarometers. Examples of calibrations for several sensors are presented and also an uncertainty budget for the Brüel & Kjaer type 4160 laboratory standard microphones, commonly used for primary calibrations. Finally, the metrological performance of the laser pistonphone is demonstrated by comparing the calibration results with those obtained with alternative methods.

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“…Firstly, sound pressures both in the pistonphone and acoustic transducer will decrease due to the coupled pressure leakage and heat conduction effect. 25,26 Secondly, these sound pressures couple with the diaphragm elasticity, and determine the diaphragm deformation. [27][28][29] Based on these, explicit sensitivity models characterizing the relationship between the diaphragm deformation and structures of acoustic transducer and pistonphone were derived.…”

Section: Introductionmentioning

confidence: 99%

Theoretical study on the phase sensitivity of condenser type acoustic transducers at low frequencies

Liu

Zhang

et al. 2021

Journal of Low Frequency Noise, Vibration and Active Control

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The phase sensitivity of the condenser type acoustic transducers at low frequencies is crucial for locating large-scale natural and manmade activities, but is now commonly calibrated based on comparison methods. Although the primary method, which traces its sensitivity back to the international standard unit is few studied. Recently, the explicit sensitivity models of the condenser type acoustic transducers based on the laser-pistonphone technique are built, and can be used to study the phase responses of acoustic transducers at infrasonic frequencies. So that, in this paper, the phase sensitivities of acoustic transducers when its rear vent connected to the calibrating sound field or outside atmosphere are studied in detail. Secondly, time domain analysis of generated sound pressures by displacement excitation are derived to reveal the mechanism of phase variation. Calculations show two distinct sensitivities with 90° phase lead and −10° phase lag limits for vent in field and vent out field calibrations, which are dominated by the pressure leakage and heat conduction effects at infrasonic frequencies.

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A study on the pressure leakage correction of pistonphones at infrasonic frequencies

Cited by 13 publications

References 13 publications

Investigation of sound pressure leakage effect for primary calibration down to 10⁻² Hz using a laser pistonphone system

Investigation of sound pressure leakage effect for primary calibration down to 10⁻² Hz using a laser pistonphone system

A laser pistonphone designed for absolute calibration of infrasound sensors from 10 mHz up to 20 Hz

Theoretical study on the phase sensitivity of condenser type acoustic transducers at low frequencies

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A study on the pressure leakage correction of pistonphones at infrasonic frequencies

Cited by 13 publications

References 13 publications

Investigation of sound pressure leakage effect for primary calibration down to 10−2 Hz using a laser pistonphone system

Investigation of sound pressure leakage effect for primary calibration down to 10−2 Hz using a laser pistonphone system

A laser pistonphone designed for absolute calibration of infrasound sensors from 10 mHz up to 20 Hz

Theoretical study on the phase sensitivity of condenser type acoustic transducers at low frequencies

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Investigation of sound pressure leakage effect for primary calibration down to 10⁻² Hz using a laser pistonphone system

Investigation of sound pressure leakage effect for primary calibration down to 10⁻² Hz using a laser pistonphone system