6
Locating a Sonde or Camera Head
Before you begin, you must choose a Sonde or camera head
that will match the same frequency as the receiver. You will
need a Sonde with a frequency of 512Hz to use with the
RL8873 Receiver.
The key to Camera/Sonde locating success is practice and
patience. Before going out on your first locate, it is a good idea
to take your receiver and Sonde out and try locating the Sonde
and calculating the depth.
Attaching a Push Device to the Sonde
Attaching a push rod to the Sonde can be accomplished by
using the coupling on the end of the Sonde. A spring coupling
is recommended to allow the Sonde to move easier. Or, if you
need to attach the Sonde to a sewer auger, it is recommended
you use duct tape and apply as the shown in the figure below. If
taping the Sonde on a metal pushing device, it is recommended
to place the battery side of the Sonde closest to the device. This
will allow for the best performance. Wrap the snake for approx-
imately 1 foot in the location where the Sonde is going to be
attached. Also attaching the Sonde 18 inches behind the cutting
head is recommended. First, wrap the Sonde in the duct tape
and then attach the Sonde to the snake
using the duct tape.
Blind Search
The Blind Search locating
technique is used if the oper-
ator is not aware if a buried
utility exists. Two people are
needed for this technique.
The transmitter and the
receiver are Held 25 feet
away from each other. Each
operator walks at the same
speed keeping a distance
of 25 feet from each other.
When the receiver gives an
audio response, then a buried
utility is present between the
receiver and the transmitter.
Selecting the Tracing Signal
The choice of LOW (512hz, 640hz), MID-RANGE (8khz, 9khz,
33khz), HIGH (65khz, 82khz, 200khz, & 478khz) frequency is
dependent on the conditions of the locate.
The frequencies each have their advantages. It is recom-
mended to begin by using the frequencies, 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, 9kHz or 33kHz. Repeat
adjustments of ground and connection point again before
switching to 65khz, 82khz, 200khz, & 478khz.
Lower frequency signal is usually preferred to the high
frequency signal, because it is much less susceptible to
locating errors caused by nearby cables or pipes. The low
frequency locating range is also much longer than the high
frequency. The low frequency signal will not travel well
through disconnected shield bonds or insulated pipe bushing.
Mid-range frequencies take the best of both high and low
frequency. The mid-range frequency is not very susceptible
to bleed off or coupling, but it can jump impedance on the
utility better than the low frequencies. It is still best to use low,
but mid-range frequencies are some of the most common
frequencies used to locate.
The high frequency signal is also better for “jumping” discon-
nected shield bonds or grounds, or tracing signal may indi-
cate one of these characteristics. The locating range is quite
short for the high frequency signal so the transmitter must
be repositioned more often during the tracing operation. This
Frequency is also useful for applying a signal using transmitter
induction and for coupler application using the Flexicoupler or
the hard coupler.
Push-Rod
Adapter
Attach 18"
from end
Pre Tape
Push Rod 12”
Wrap tape completely
around sonde
Attach wrapped sonde to
pre-taped section of push device
Use the supplied 3/8” x
16 unc and 5/16" x 18
unc push-rod adapters or
pre-tape the push device for
12" leaving 18" from the end
Back
Sonde
Side
Front
Side
Transmitter
Receiver
25' (7.5 meters) between
Transmitter and Receiver