Radiodetection RD4000T10, Руководство пользователя

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RD4000 Locating System User Manual
Page 34
Applying the transmitter signal
The transmitter signal can be connected, clamped or induced
to the target line in the same way as the signal for line tracing
is applied.
Measuring current
•
Pinpoint the line and confirm the accuracy of the peak pinpoint with a null pinpoint. Check the receiver is
directly over the line, with the antennas at right angles to it and vertical
•
Press depth/current key. Depth will be displayed for approximately five seconds, and then the depth and
current value in milli-amps will be displayed for five seconds
A signal coupled to a nearby line may distort the accuracy of the measurement. If the accuracy of the reading is
suspect, sweep the area to check if other nearby lines are radiating the signal. If other signals are causing
interference, it may be necessary to make the current measurement at another point along the line.
Both antennas are needed to make a current measurement and receiver accessory antennas such as a normal
clamp or stethoscope cannot be used. Because current measurement is a function of depth, it is only available
in the locating modes. It is also available with Current Direction (CD) clamps.
Current direction (CD)
Understanding CD
Current direction recognition is a feature that helps to positively identify a line at points distant from the
application of the signal. It is highly desirable, if not essential, for positive identification of long distance lines.
These lines can be traced and positively identified through congested areas or when running parallel to other
lines.
The CD feature on the RD400 receiver indicates the direction of the
current flow on a line. Identity of the target line is established if the
receiver display indicates that the current is flowing forward and
away from the point of application of the transmitter signal.
Signal that has coupled onto adjacent lines finds a return path to
the point of the original signal application. This is indicated by the
receiver arrow pointing back towards the transmitter.
This is in contrast to the forward pointing arrow indicating the target
line.
The CD transmitter signal must be directly coupled to the target line and with a remote ground connection. It
cannot be applied by normal clamp or induction but can be applied with a transmitter CD clamp.
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