Introduction to Acoustics

156 Part A Propagation of Sound
Part A 5.2
Type
Resonance frequency fr
Depth
Envelope dimensions (in.)
TVR at fr
Midband OCV
Suggested band
Beam type
Input power
d)
270
1 2 3 4 5 6 7 8 9
330
0 30
300 60
240 120
10dB/div
Specifications (nominal)
210 180 150
Directivity pattern at 10 kHz
10
in.
Projector/Hydrophone
11,5 kHz
1250 m
6.5D
149 dB/(µPa/V@1m)
–188 dB/(1V/µPa)
0.01–20 kHz
Spherical
10000 W
90
a)
dB re µPa/V @ 1m
150
140
130
120
110
4
b)
db re 1V/µPa
–180
–190
–200
c)
Conductance (G)/Susceptance (B) (µs)
8000
6000
4000
2000
4
0
4
6 8 10 12 14 16 18 20 22
Frequency (kHz)
6 8 10 12 14 16 18 20 22
Frequency (kHz)
B
6 8 10 12 14 16 18 20 22
Frequency (kHz)
Fig. 5.8a–d Typical specification sheet of a powerful underwater acoustic transponder (top left). (a) Transmitting voltage
response. (b) Receiving voltage response. (c) Real (full line) and imaginary part (dashed line) of the water admittance Y.
(d) Directionality pattern at one frequency (Courtesy of International Transducer Corp.)
mitting voltage response, this corresponds to a source
level of nearly 210 dB re µPa at the resonant frequency.
Finally, Fig. 5.8d represents the directionality pattern
at a given frequency. It shows that the ITC-1007 is
omnidirectional at 10 kHz.
When transducers have to be coupled to a power amplifier
or another electronic device, it may be useful to
model the transducer as an electronic circuit (Fig. 5.9a).
The frequency dependence of the conductance G and
susceptance B (Fig. 5.8c) yield the components of the
G