Textron GREENLEE 521A Manual De Instrucciones página 8

• Larger nicks in the wire can be located in almost the same way as locating
opens. Follow the null and strong signal along the sides of the wire until the
signal becomes very weak along the sides of the null. This will occur within a
relatively short distance. The transmitted signal bleeds to ground at the nick and
then wants to return to the ground stake along the outside of the wire itself. The
majority of signals will stop at the nick indicated by the low receiver reading just
beyond the nick. (Refer to Figure 4.)
• To more accurately define the location of an open or larger nick (ground fault),
position the receiver tip on the ground near the point where the last strong signal
was detected along the side of the path. The receiver tip should be pointing at
the ground and be approximately 6 inches to either side from the null. Because
you are so much closer to the path, the sensitivity knob must be adjusted down
until the meter reads just below 10.
While maintaining the 6-inch distance from the null, move the receiver down the
line, paying close attention to the meter reading. Once you pass the open or
nick, the meter will fall off rapidly.
Receiver
No Null
Broad
Signal
Open
Figure 3 – Locating End of Broken Wire
Receiver
Meter
Null Over Path
Signal Intensity
Wire
Receiver
Wire
Figure 4 – Locating Wire Nick
8
Receiver
Meter
Signal
Intensity
Nick
Field Return Signal