【Function
and Purpose】
Without
excavation, the outer coating condition detector is able to find out the
position, running direction, depth of underground metal pipes, as well as the
damaged points and their number, size, and distance between them on underground
metal pipes in a convenient and accurate way.
【Purpose】
★Acceptance on pipes
in compliance with the standards of SYJN4029-88 and GJJ33089;
★Completion acceptance
on newly laid pipes;
★Regular detection on
pipes according to safety regulations to confirm the cathode protection
effects;
★Location of branches
on the main pipeline;
★Testing of old pipes
to determine if they need overhaul or not
★Check on underground
pipeline distribution before excavation at the construction section, in order
to prevent the underground pipelines for oil, gas, water, electricity, etc.
from being destroyed during construction.
【Characteristics】
★ A brand new
technology of digital filtering used to set the range of leakage points, to record
their number automatically and to display the distance between them precisely;
★ Various
detection methods are available, with automatic changeover, and the transmitter
sends a reminder signal to the receiver before battery under-voltage and auto
power-off, the data automatically saved at power-off;
★ Possibility of
automatic measuring the pipe-to-earth resistance, with high-frequency alarm
signal output, of extremely strong anti-interference capability; Power output of
the transmitter adjusted as the detection distance increases, and the
transmitter automatically power off when detection finished, which improve the
detection effects of the equipment and extends the life time of the battery.
【Primary
Technical Parameters】
A.
Technical parameters of the transmitter:
●Power: 5-25W,
adjustable automatically
●Output impedance
matching: 5-500Ω
●Transmitting
distance: 0.03-5Km，able to be moved beyond 5km gradually
●Working power supply:
12V（NiCd battery）
●weight: 3.5Kg
●Overall dimension: 245×236×105
B.
Technical parameters of the pipe locator
●Sensitivity: 0.1mV
●Positional deviation: ≤5cm
●Investigation depth: ≤5m
●Recorded distance
precision: ≤0.1% of detection distance
●Working power supply:
9.6V NiCd battery
●Overall dimension: 185×135×110
C.
Technical parameters of the leakage detector:
●Leakage detection
accuracy≥0.25mm2
●Working power supply:
9.6V NiCd battery pack
●Overall dimension: 185×135×110
【Detection
Principles and Methodology】
Principle
and methodology for running direction and buried depth detection: determine the
position, running direction and depth of underground pipelines by detecting the
magnetic field of underground pipelines via sending a specified high-frequency
modulated signal to underground pipelines.
【Methods:
peak method and zero method】
Detection
principles and methodology: by sending a specified high-frequency modulated
signal to the underground pipeline, the loop is formed between the damaged
point on the coating and the earth, which radiates to the ground, with the
strongest signal right above the damaged point. That’s the principle how we can
find out the damaged point on the coating.
The
coating condition detector adopts “body capacitance method”, i.e., with human
body as the induction element of the leakage detector. When the operator walks
close to the leakage point, the leakage detector begins to react. When he is
right above the leakage point, the volume in the loudspeaker is the highest and
the displayed value is the largest. That’s how we can find the leakage point.
