Abstract:In order to solve the problem that the correlation delay time τ of the traditional autocorrelator-based experimental system is too large when detecting the air free-field sound pressure, an anechoic box environment was built, a non-fixed-frequency-shift optical system, and a signal acquisition and processing system were designed for detecting the air free-field sound pressure based on the photon correlation method.The method decreased the step value of autocorrelation delay time (τ) to 1μs, reducing the measurement error of sound pressure by 0.2dB compared to traditional autocorrelator-based experimental systems.Finally, a comparison with the microphone method and the conventional photon autocorrelation method was made, and the results of the measurement of 106.4dB sound pressure in the range of 600~1200Hz showed that the maximum deviation of the proposed method for the measurement of the sound pressure in the air sound field was 0.6dB.
KOUKOULAS T, KANG J, HE L. Optical experimentally traceable realisation of acoustical pressures for sound-in-air me-trology [C]//Proc 25th Int Congr Sound Vib. Hiroshima, Japan, 2018.
[6]
VALIERE J C, HERZOG P, VALEAU V, et al. Acoustic velocity measurements in the air by means of laser Doppler velocimetry: dynamic and frequency range limitations and signal processing improvements [J]. Journal of sound and vibration, 2000, 229(3): 607-626.
[7]
HANN D B, GREATED C A. The measurement of flow velocity and acoustic particle velocity using particle-image velocimetry [J]. Measurement Science and Technology, 1997, 8(12): 1517.
FENG X J, HE L B, NIU F, et al. Method for reproducing sound pressure values based on photon correlation spectroscopy analysis [J]. Acta Optica Sinica, 2016, 36(7): 162-168.
[9]
KOUKOULAS T, PIPER B, THEOBALD P. Gated photon correlation spectroscopy for acoustical particle velocity measurements in free-field conditions [J]. The Journal of the Acoustical Society of America, 2013, 133(3): EL156-EL161.
KANG J, HE L B, FENG X J, et al. Preliminary study on the influence of fringe distortion on sound pressure measurement using the LDV method [C]//Proceedings of the National Acoustic Conference of the Acoustical Society of China. Harbin, China, 2017.
WANG M, YANG P, HE L B, et al. Design of a zero-crossing demodulation system for reproducing underwater sound pressure using optical methods [J]. Acta Metrologica Sinica, 2019,40(2): 315-318.
ZHANG Z K, FENG X J, HE L B, et al. Optimization study of optical method for measuring sound pressure values in standing wave tubes [J]. Metrology and Measurement Technology, 2020(5): 40-45.
[18]
MIDDLETON D. An introduction to statistical communication theory [M]. New York: McGraw-Hill, 1960.
HUANG D K, LI C R, ZHU M H. Effect of scattered particle size on signal-to-noise ratio in laser doppler velocimetry [J]. Optical Technology, 2003(2): 164-165.
[1]
KOUKOULAS T, PIPER B. Towards direct realisation of the SI unit of sound pressure in the audible hearing range based on optical free-field acoustic particle measurements [J]. Applied Physics Letters, 2015, 106(16):164101.
[3]
YEH Y, CUMMINS H Z. Localized fluid flow measurements with an He-Ne laser spectrometer [J]. Applied Physics Letters, 1964, 4(10): 176-178.
[5]
TAYLOR K J. Absolute measurement of acoustic particle velocity [J]. The Journal of the Acoustical Society of America, 1976, 59(3): 691-694.
WANG H Y, FENG X J, ZHU H J, et al. Optical scanning method for two-dimensional sound field [J]. Acta Metrologica Sinica, 2018, 39(3): 381-385.
[19]
SHARPE J P, GREATED C A. The measurement of periodic acoustic fields using photon correlation spect-roscopy [J]. Journal of Physics D: Applied Physics, 1987, 20(4): 418.
[14]
GONG X, XIONG X, ZHAO Y, et al. Boosting the signal intensity of nanoelectrospray ionization by using a polarity-reversing high-voltage strategy [J]. Analytical Chemistry, 2017, 89(13): 7009-7016.
CHO W H, KOUKOULAS T. Signal processing considerations on the optical measurement of acoustic particle velocities in free-field conditions [J]. IEEE Transactions on Instrumentation and Measurement, 2019, 69(7): 4021-4032.
YANG R Y, ZHAO J, WANG D Y, et al. Study on improving measurement accuracy of airborne sound pressure using photon correlation method with interference angle microscopy [J]. Acta Metrologica Sinica, 2022,43(7): 927-933.