Characteristics Of The Ultrasonic Wave In Water; Sound Velocity - Furuno CSH-5 MARK-2 Operator's Manual

14. CHARACTERISTICS OF THE

Sound Velocity

C
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
ULTRASONIC WAVE IN WATER
The purpose of this chapter is to provide an overview of the charac-
teristics of the ultrasonic wave in water.
It is generally known that an ultrasonic wave travels 1500 meters per
second in sea water, but in practice, some amount of variation arises
depending on the season and area from differences in the following
three factors:
Water temperature .............................. [ C]
Salinity density ................................... S [%]
Water pressure (water depth) .............. h [m]
Therefore, for propagation in surface water the velocity changes not
only by area but also by direction of the wave propagation. The equa-
tion obtained thru numerous measurements is;
C= 1410 + 4.21 - 0.037
Velocity (m/sec)
1445.4
1450.0
1454.4
1458.8
1463.1
1467.2
1471.3
1475.3
1479.2
1483.0
1486.7
1490.3
1493.8
1497.3
1500.6
1503.8
1507.0
1510.0
1513.0
1515.9
1518.7
2
+ 1.145S + 0.0168h [m/s]
Correction value with respect to
Depth and Temperature (m/s.)
Depth
(m)
100 200 300 400
C
5 1.8 3.6 5.4
10 1.8 3.6 5.4
15 1.8 3.6 5.4
20 1.8 3.6 5.4
25 1.8 3.6 5.4
Fig.1 Sound Velocity
58
500 600 700
7.3 9.1 10.9 14.5
7.2 9.0 10.8 14.5
7.2 9.0 10.8 14.4
7.2 9.0 10.8 14.4
7.3 9.1 10.9 14.5