110 Lecture 6 
APPAREILLAGE MECANIQUE 
d' EXPLOITATION de la CUVE 
a) petit chariot 
b) petit pont 
c) grand chariot 
d) grand pont 
e) selsyn d'orientation 
f) entrainement des chariots 
g) volant d'orientation 
h) frein des chariots 
i) frein des ponts 
) entrainement des ponts 
) 
) 
absorbeurs 
rail du palan 
i 
k 
Dimentions interieures 
longueur 4570 
largeur 3140 
hauteur 3150 
; 
be 
4 
H 
L 
H 
f 
H 
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H 
H 
H 
H 
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ma 2 
Sese le 
Fig. 6.7. Schematic of 
a transducer-calibra- 
tion tank with fittings. 
6.2.2. Principle of the Pulse Method 
Acoustic calibration of transducers must be carried out in a free acoustic 
field. When using the pulse method, each single pulse has to be considered as 
traveling in such a field at the exact moment when it is measured, and it must 
not be disturbed by interference produced by reflection on the tank boundary 
wall. This condition imposes a proper separation distance between projector 
and receiver, and a determined value of pulse length and repetition rate. 
