The document discusses underground utility detection and locating buried pipes and cables. It covers several key topics: - The importance of safety when digging and how locating utilities helps avoid damage - Common utility detection techniques like electromagnetic induction, ground penetrating radar, and cable locators - How cable locators work to detect active and passive signals around buried lines - Processes for sweeping an area and tracing individual utilities using cable locators - Standards and guidelines for underground utility mapping in Malaysia

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2.  Underground Utility Detection??
Utility Detection
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3.  Safety on site is a necessary ingredient of all civil works.
 Information provided by locating before digging is an essential
contribution to safe digging.
 Spiking a buried power cable or fracturing a pipeline is a cause of
serious and dramatic danger that can mutilate or even kill.
 Knowing their presence and position helps avoid the possibility of
damage.
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4.  Trenching Damages
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5. What’s all this about locating?
 It’s about ;
• reducing unnecessary cost
• efficient working
• site safety
• maintaining essential services to the community
 Information is the end product of locating buried utility pipes and
cables.
 Positive, accurate and precise information is the only kind of
information worth having or worth paying for.
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6.  Faulty or incomplete information can misled, it can be the cause of
unnecessary cost and it can expose people to danger.
 Underground Utility Mapping is a process to determine the utilities
beneath the ground surface.
 Such as : telephone line, power distribution cable, natural gas
pipeline, fiber optic line, street light cable, water
pipes,sewerage etc.
Faulty 01 Faulty 02
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7.  Electromagnetic induction was discovered
by Michael Faraday in 1831
 The earliest record of using electromagnetic
technology to locate buried cables dates
from around 1910
Michael Faraday
1791-1867 7
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8. The photograph shows a cable locator from a coil wound round a
wooden truss; the coil is just visible at the front of the truss
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9.  Survey and Mapping Department are responsible
to manage utility mapping for Malaysia (24th
August 1994)
 To handle disruption of existing utility services
due to excavation works
 Follow the ‘
Standard Guideline for Underground Utility Mapping
’
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10.  Underground utility installations involved the use of different
materials and sizes and can be placed at different depths.
 In addition, the environment in which it is buried can vary from
one place to another and can be packed with a variety of utility
placement.
 This makes possible the need for using more than one
technique to detect its position.
 The selection of appropriate techniques is essential to ensure
effective detection.
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11.  In general, the detection techniques that can be used can be
classified as follows:
• Electromagnetic
 Pipe and Cable Locator (PCL)
 Terrain Conductivity
 Resistivity Measurements
 Metal Detectors
 Ground Penetrating Radar (GPR)
 Optical Methods
 X-ray Methods (Penetrating Radiation)
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12.  In general, the detection techniques that can be used can be
classified as follows:
• Magnetic
 Magnetometer
 Total Field Measurements
 Gradiometric Measurements
• Elastic Wave
 Seismic Reflection
 Seismic Refraction However, utility detection activity typically
 Acoustic Emission involve two types of equipment
* Pipe and Cable Locators (PCL)
* Ground penetration radar (GPR).
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14.  A PCL does not locate buried pipes or cables
 It detects a magnetic field around the line created by an alternating
current-ac-flowing along the line.
 This magnetic field forms a cylindrical shape around the line and is
known as the ‘SIGNAL’
 PCL should be able to provide
accuracy of ± 5% from the
true value of location and
depth.
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17.  Signal;
• Active Signal
 Is produce by a signal transmitter and applied to a line so that it can be
located and traced with a receiver.
 The signal transmitter can also flood an area with signal so that all the
lines in the area can be located
• Passive Signal
 Occur ‘naturally’ on lines as an effect of 50/60Hz electric power energy or
VLF radio energy
** Despite the existence of passive signals the best signal to
locate and trace a line is an active signal which has been
deliberately applied for the purpose of locating and tracing
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18.  Active Signal;
• An active signal is applied to a line from a transmitter so that the
line can be traced and located with a receiver.
• To ensure more accurate result, these mode should be used;
 Direct Connection
 Induction
 Clamping
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19.  Direct Connection
• The output ac voltage from the signal transmitter is connected directly
to the pipe or cable at an access point such as a valve, meter or end of
the conductor, and the circuit is completed by a connection to a stake
or the ground connection point
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20.  Direct Connection
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21.  Induction
• The aerial in a signal transmitter fed with an ac voltage sets up a
magnetic field through the coil returning through the earth below it.
• In the first drawing the transmitter aerial lies parallel to line AB and its
field links around the line which therefore has a signal induced on it.
• There is no linkage and no signal induced on line CD at right angles to
the aerial.
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22.  Clamping
• Uses the induction principle to give similar result to direct
connection, but without electrical contact to the line.
• The output from the signal transmitter is applied to a target line
by clamping round it with a split toroidal magnetic core, which
carries a primary winding magnetizing the core with the ac signal
• The line becomes the secondary of a transformer, and will carry a
strong signal, provided that it is adequately grounded on each
side.
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24.  Passive Signal;
• Are ‘naturally’ present on many buried pipes and cables.
 Eg. Power cables which carry currents as part of their normal duty.
• Current flowing in a cable produces a magnetic field or passive
signal.
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25.  Passive Signal;
• Very low frequency long wave radio energy from distant
transmitters is present in the atmosphere world-wide.
• The ground provides return paths for this energy, and burried
metallic lines form preferred paths.
• They then act as aerials re-radiating these signals.
• The signals are strong enough to be located in most part of the
country.
• This can be check by trial and error before relying on them for
location work.
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26.  Passive Signal;
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27.  Sweeping
• To locate any conductor underground
• Walk in grid pattern as shown on illustration
• Sweeping in two perpendicular directions
• ‘STOP’ when you get a response
• Move the transmitter to that point and trace the conductor
you’ve found out of the area of interest, marking as you go.
• Return to your starting point and resume sweeping, looking for
more conductors to trace.
• When finished sweeping using the inductive method, sweep
again using passive power mode.
• This technique will reveal all grounded metal pipes and cables,
and non-conducting lines with properly installed tracer wires.
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28.  SWEEPING
Sweep
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29.  TRACING
• To trace an individual pipe or cable, it’s best to apply signal to
the targeted line with the conductive method or the inductive
clamp method.
• If this isn’t possible, you can still use the inductive method but
other conductors are more likely to pick up a signal.
• Move slowly while tracing the cable, moving the receiver side
toside over the trace path. Pay attention to handle alignment.
• Mark the path as you go, and, if in manual gain mode,
remember to adjust gain periodically as you move away from
the transmitter and signal strength declines.
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30.  PCL
RD 7000/8000 Demo
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32.  Ground-penetrating radar (GPR) is a geophysical method that uses
radar pulses to image the subsurface.
 This nondestructive method uses electromagnetic radiation in the
microwave band (UHF/VHF frequencies) of the radio spectrum, and
detects the reflected signals from subsurface structures.
 GPR can be used in a variety of media, including rock, soil, ice, fresh
water, pavements and structures. It can detect objects, changes in
material, and voids and cracks.
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33.  Depending on the depth and soil conditions, a range of frequencies
should be used:
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35.  GPR
01 02 03
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36. The American Public Works Association (APWA) Uniform Color Codes for
temporary marking of underground utilities are listed below:
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37. Marking on site
Normally Marked:
Power Line - P
Water - W
Sewer - S
Telephone Line - T
Gas Pipe - G
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38.  ABC & XYZ of Locating Buried Pipes and Cables (for the beginner
and the specialist)
• Radiodetection Limited
 Locating 101- A quick guide to underground locating
• Schonstedt
 Pekeliling KPUP bil. 1/2006 – Garis Panduan Pemetaan Utiliti
Bawah Tanah
• Jupem
 Pekeliling KPUP bil. 1/2007 – Garis Panduan Ukuran Pepasangan
Utiliti
• Jupem
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