Radiodetection rd7000+, Руководство по эксплуатации

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© 2014 Radiodetection Ltd 15
Section 4 - Locating cables and pipes
This section introduces the principals and techniques of locating buried cable and pipe utilities with the
system. For more information on the theory of cable and pipe location, please refer to
ABC & XYZ of locating
buried pipes and cables , which is available to download from www.radiodetection.com
4.1 Frequencies
The marker locator supports a range of active
and passive frequencies.
For a complete list of supported frequencies, please
refer to the tables in Appendix 12.8, 12.8.1 and 12.8.2.
4.1.1 Passive frequencies
Passive frequency detection takes advantage of signals
that may be present on buried metallic conductors. The
marker locator supports up to three types of
passive frequencies:
Power , Radio and CPS (DLM
model only).
You can detect these frequencies without the aid of a
transmitter if they are present on the utility you are
surveying.
4.1.2 Active frequencies
Active frequencies are applied to a buried conductor
using the transmitter. The transmitter can apply a signal
using three methods:
Direct connection
In direct connection, you connect the transmitter output
directly to the utility. The transmitter will then apply a
discrete signal which you can locate using the locator.
This is the preferred method of applying a transmitter
signal to a utility and in the majority of applications will
apply a stronger signal to the utility, which may increase
the locate distance.
To directly connect to a non-energized conductive utility:
1 Switch the transmitter off
2 Connect the direct connection lead into the
transmitter accessory socket
3 Clip the red connection lead to the utility ensuring
that the area around the connection is clean and
that a positive connection is achieved
4 Clip the black connection lead as far away as
possible and at 90° to the ground stake or suitable
ground point nearby ensuring that a positive
connection is achieved
5 The display will show the Direct connection lead
connected icon
For more information about signal clamps and other
direct connection accessories, please refer to Section 8
.
WARNING! Direct connection to live conductors is
POTENTIALLY LETHAL. Direct connections to live
conductors should be attempted by fully qualified personnel
only using the relevant products that allow connections to
energized lines.
WARNING! The transmitter is capable of outputting
potentially lethal voltages. Take care when handling the
terminals, connection leads and ground stake, notify other
technicians working on the line of the hazard and guard
exposed conductors to prevent accidental contact.
Induction
In this mode of operation the transmitter is placed on
the ground over or near the survey area. If a direct
connection lead is not plugged into the transmitter, it will
automatically go into induction mode. In this mode, only
frequencies applicable for induction mode will be made
available as the key is pressed.
Once activated the transmitter will induce the signal
indiscriminately to any nearby buried conductors.
Please note that these signals will also be airborne and
it is advisable to keep the distance between the
transmitter and locator at least 10m /
30’ – this distance
may need to be increased, particularly if depth
measurements are taken.
Clamp
The optional signal clamp can be connected to the
transmitter and clamped around a cable or pipe to apply
the transmitter signal. This method of applying the
transmitter signal is particularly useful on insulated live
wires and removes the need to disconnect the supply to
the cable. Clamps are available
up to 8.5” / 215mm in
diameter.
WARNING! Do not clamp around uninsulated live
conductors
Direct connection
lead connected