Notes on Selecting the Tracing Signal
The choice of 815 Hz, 8 kHz or 82 kHz Frequency is dependent on the conditions of the locate.
The 815 Hz, 8 kHz and 82 kHz signals each have their advantages. It is recommended to begin by using
the 815 Hz signal, and continue as long as you are confident in the results. If the signal is very weak try to
adjust the connection or grounding. If there is no improvement in signal then try 8 kHz. Repeat adjustments
of ground and connection point again until switching to 82 kHz.
815 Hz (lower frequency) signal is usually preferred to the 8 kHz (mid-range frequency) and 82 kHz (high
frequency) signal, because it is much less susceptible to locating errors caused by nearby cables or pipes.
The 815 Hz locating range is also much longer than the 82 kHz signal. The 815 Hz signal will not travel
well through disconnected shield bonds or insulated pipe bushing.
8 kHz takes the best of both high and low frequency. This mid range frequency is not very susceptible to
bleed off or coupling, but it can jump impedance on the utility better than the 815 Hz. It is still best to use
815 Hz, but 8 kHz is one of the most common frequencies used to locate coaxial cable and telecom pairs.
The 82 kHz (higher frequency) is sometimes better than the 815 Hz (lower frequency) for locating sharp
corners in cables or pipes. The 82 kHz signal is also better for “jumping” disconnected shield bonds or
grounds, or tracing signal may indicate one of these characteristics. The locating range is quite short for
the 82 kHz signal so the T
RANSMITTER
must be repositioned more often during the tracing operation. This
FREQUENCY
is also useful for applying a signal using the F
LEXICOUPLER OR THE
H
ARD
C
OUPLER
.
Both the 815 Hz and the 82 kHz may be transmitted simultaneously. When this option is selected the user may
change frequencies on the receiver aiding in tracing verification.
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