Instruction Manual

81
6−3 White Noise Method
- Case ③ -
In this case, since both the pipe diameter (sound velocity) and pipe length are unknown, the sound velocity
value obtained from the pipe material type is input as an estimated value to temporarily detect the leak
location.
Refer to the table below for a list of sound velocities.
● In general, the speed at which the leaked sound propagates in the pipe varies depending on the material
and diameter. Metal pipes allow higher velocities than plastic pipes, and if the material is the same, the
sound velocity is slower for larger diameters.
Pipe material
Diameter (mm)
Sound velocity (m/s)
Ductile iron pipe (DIP)
75 to 1500
1346 to 1057
PVC pipe (VP)
13 to 500
622 to 345
Polyethylene pipe (PE1)
10 to 50
200 to 179
Polyethylene pipe (PE2)
10 to 50
360 to 341
Press the menu switch .
Tap “White noise” to display the screen on the left.
In this case, since the pipe diameter and pipe length
are unknown, the sound velocity estimated from the
pipe material is entered.
Tap Pipe length from estimated velocity value.
The screen on the left is displayed.
Tap the pre-amplifier to be used and enter the
estimated sound velocity value.
Tap "Run".