The dominating method of measuring sound intensity in air is based on the combination of two pressure microphones. However, a sound intensity probe that combines an acoustic particle velocity transducer with a pressure microphone has recently become available. This paper examines, discusses, and compares the two measurement principles with particular regard to the sources of error in sound power determination. It is shown that the phase calibration of intensity probes that combine different transducers is very critical below 500 Hz if the measurement surface is very close to the source under test. The problem is reduced if the measurement surface is moved further away from the source. The calibration can be carried out in an anechoic room.
REFERENCES
1.
2.
IEC Publication 61043
, “Instruments for the measurement of sound intensity–Measurements with pairs of pressure sensing microphones
,” 1993
.3.
American National Standard ANSI S1.9-1996
, “Instruments for the measurement of sound intensity
,” 1996
.4.
T. B.
Gabrielson
, D. L.
Gardner
, and S. T.
Garret
, “A simple neutrally buoyant sensor for direct measurement of particle velocity and intensity in water
,” J. Acoust. Soc. Am.
97
, 2227
–2237
(1995
).5.
K.
Kim
, T.
Gabrielson
, and G. C.
Lauchle
, “Development of an accelerometer-based underwater acoustic intensity sensor
,” J. Acoust. Soc. Am.
116
, 3384
–3392
(2004
).6.
H.-E.
de Bree
, P.
Leussink
, T.
Korthorst
, H.
Jansen
, T.
Lammerink
, and M.
Elwensoek
, “The Microflown: A novel device measuring acoustical flows
,” Sens. Actuators, A
SNA054∕1-3
, 552
–557
(1996
).7.
H.-E.
de Bree
, “The Microflown: An acoustic particle velocity sensor
,” Acoust. Aust.
31
, 91
–94
(2003
).8.
R.
Raangs
, W. F.
Druyvesteyn
, and H.-E.
de Bree
, “A low-cost intensity probe
,” J. Audio Eng. Soc.
51
, 344
–357
(2003
).9.
K. J.
Bastyr
, G. C.
Lauchle
, and J. A.
McConnell
, “Development of a velocity gradient underwater acoustic intensity sensor
,” J. Acoust. Soc. Am.
106
, 3178
–3188
(1999
).10.
G.
Rasmussen
and M.
Brock
, “Acoustic intensity measurement probe
,” Proceedings of Recent Developments in Acoustic Intensity Measurement
, Senlis, France, 1981
, pp. 81
–88
.11.
F.
Jacobsen
, V.
Cutanda
, and P. M.
Juhl
, “A numerical and experimental investigation of the performance of sound intensity probes at high frequencies
,” J. Acoust. Soc. Am.
103
, 953
–961
(1998
).12.
F.
Jacobsen
, V.
Cutanda
, and P. M.
Juhl
, “A sound intensity probe for measuring from 50 Hz to 10 kHz
,” Brüel & Kjær Tech. Rev.
1
, 1
–8
(1996
).13.
Anonymous
, “Product data, sound intensity pair–type 4197
,” Brüel & Kjær
, Nærum, Denmark.14.
E.
Frederiksen
and O.
Schultz
, “Pressure microphones for intensity measurements with significantly improved phase properties
,” Brüel & Kjær Tech. Rev.
4
, 11
–12
(1986
).15.
T. G.
Nielsen
, “A field calibrated real time system for intensity measurements
,” Proceedings of Inter-Noise 88
, Avignon, France, 1988
, pp. 123
–126
.16.
F.
Jacobsen
, “Sound field indicators: Useful tools
,” Noise Control Eng. J.
35
, 37
–46
(1990
).17.
S.
Gade
, “Validity of intensity measurements in partially diffuse sound field
,” Brüel & Kjær Tech. Rev.
4
, 3
–31
(1985
).18.
Anonymous
, “Technical documentation, sound intensity software BZ 7205 for 2260 Investigator
,” Brüel & Kjær
, Nærum, Denmark.19.
F.
Jacobsen
, “A simple and effective correction for phase mismatch in intensity probes
,” Appl. Acoust.
33
, 165
–180
(1991
).20.
F.
Jacobsen
, “Spatial sampling errors in sound power estimation based upon intensity
,” J. Sound Vib.
145
, 129
–149
(1991
).21.
J. A.
Mann
, III, J.
Tichy
, and A. J.
Romano
, “Instantaneous and time-averaged energy transfer in acoustic fields
,” J. Acoust. Soc. Am.
82
, 17
–30
(1987
).22.
F.
Jacobsen
, “Active and reactive, coherent and incoherent sound fields
,” J. Sound Vib.
130
, 493
–507
(1989
).23.
J.-C.
Pascal
, “Estimation de la puissance acoustique à l’aide d’intensimètres
,” Proceedings of Recent Developments in Acoustic Intensity Measurement
, Senlis, France, 1981
, pp. 179
–185
.24.
J. Y.
Chung
, “Cross-spectral method of measuring acoustic intensity without error caused by instrument phase mismatch
,” J. Acoust. Soc. Am.
64
, 1613
–1616
(1978
).25.
S. J.
Elliott
, “Errors in acoustic intensity measurements
,” J. Sound Vib.
78
, 439
–445
(1981
).26.
F.
Jacobsen
and E. S.
Olsen
, “The influence of microphone vents on the performance of sound intensity probes
,” Appl. Acoust.
41
, 25
–45
(1994
).27.
F.
Ingerslev
, O. J.
Pedersen
, P. K.
Møller
, and J.
Kristensen
, “New rooms for acoustic measurements at the Danish Technical University
,” Acustica
19
, 185
–199
(1967
/68).28.
F.
Jacobsen
and H.-E.
de Bree
, “Intensity-based sound power determination under adverse sound field conditions: p-p versus p-u probes
,” Proceedings of Twelfth International Congress on Sound and Vibration
, Lisbon, Portugal, 2005
.29.
F.
Jacobsen
, “Active and reactive sound intensity in a reverberant sound field
,” J. Sound Vib.
143
, 231
–240
(1990
).© 2005 Acoustical Society of America.
2005
Acoustical Society of America
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