Instruction Manual

33
Preparation at Site
(1) Preparation of necessary conditions and
data
To find the location of the leak with the correlator
as shown in the figure below, the necessary data is
required, and the following four conditions must
be met.
① The sound from the location of the leak must be
transmitted to two or more pre-amplifiers.
● If the leak sound is transmitted to only one
pre-amplifier, the location of the leak cannot
be identified.
In that case, try reducing the distance
between the pre-amplifiers.
● It is assumed that existence of the sound of
water leakage was established by prior
investigation.
② The material of the target pipe is known.
● This is because the sound velocity (the speed
at which the sound of the water leak
propagates) depends on the pipe material.
③ The diameter of the target pipe is known.
● This is because the sound velocity (the speed
at which the sound of the water leak
propagates) depends on the pipe diameter.
④ The pipe length between the pre-amplifiers is
known.
(2) Installation of pre-amplifiers
① Candidate installation locations include fire
hydrants, gate valves, and meters.
Determine the installation locations and install
the pre-amplifiers.
● There are four pre-amplifiers: blue, red,
yellow, and green. Often only two or three
units need to be installed, not all four.
● Since the pre-amplifier is completely
waterproof, it can be immersed in the water.
● Make sure the signal reaches the
pre-amplifier as described in “3-4
Pre-Amplifier Check” on p. 22.
● Make sure the installation site and magnet of
the pre-amplifier are free from mud and dirt.
Mud and dirt may prevent correct leak
detection.
② When several leak locations exist on the same
pipe (including branch pipes), choose two
installation locations where the leak noise
between them is the maximum.
①
①
②
③
④
Leak location
(1) Preparation of necessary conditions and data
(2) Installation of pre-amplifiers