Location Methods - RIDGID SeekTech SR-20 Operator's Manual

SeekTech SR-20
NOTE! A Pole is found where field lines turn vertical. The
Equator occurs when the field lines are hori-
zontal.
Pole
Ground
Figure 27 – Dipole Field
When locating a Sonde, first set up the locate:
Activate the Sonde before putting it in the line. Select the
same Sonde frequency on the SR-20 and make sure it
is receiving the signal.
After the Sonde has been sent into the pipe, go to the
suspected Sonde location. If the direction of the pipe is
unknown, push the Sonde a shorter distance into the line
(~15 feet (5m) from the access is a good starting point).

Location Methods

There are three major parts to locating a Sonde.
The first step is to localize the sonde. The second
part is pinpointing. The third is verifying its location.
Step 1: Localize the sonde
• Hold the SR-20 so the antenna mast is pointing out-
ward. Sweep the antenna mast in the suspected di-
rection of the Sonde while observing the Signal
Strength and listening to the sound. The signal will be
highest when the antenna mast is pointing in the di-
rection of the Sonde.
• Lower the SR-20 to its normal operating position
(antenna mast vertical) and walk in the direction of the
Sonde. Approaching the Sonde, the Signal Strength
will increase and the audio tone will rise in pitch.
Use the Signal Strength and the sound to maximize
the signal.
• Maximize the Signal Strength. When it appears to be
at its highest point, place the SR-20 close to the
ground over the highsignal point. Be careful to hold
18
Pole
Ridge Tool Company
the receiver at a constant height above the ground as
distance affects Signal Strength.
• Note the Signal Strength and move away from the
high point in all directions. Move the SR-20 far
enough in all directions to verify that the Signal
Strength drops significantly on all sides. Mark the
point of highest Signal Strength with a yellow Sonde
Marker (clipped to antenna mast for convenience).
This is the suspected Sonde location.
Figure 28 – Poles and Equator of a Sonde
If while "getting closer" the Equator appears on the
screen, follow it in the direction of an increasing Signal
Strength to localize the Sonde.
Step 2: Pinpoint the Sonde
The Poles should appear on either side of the maxi-
mum signal point, an equal distance on either side if the
Sonde is level. If they are not visible on the screen at the
point of maximum Signal Strength, move from the max-
imum point perpendicular to the dotted line (Equator) until
one appears. Center the locator over the Pole.
Where the Poles occur depends on the Sonde's depth.
The deeper the Sonde, the further away from it the
Poles will be.
The dotted line represents the Equator of the Sonde.
If the Sonde is not tilted, the Equator will intersect the
Sonde at maximum Signal Strength and minimum
Measured Depth.
NOTE! Being on the Equator does not mean that the lo-
cator is over the Sonde. Always verify the locate
by maximizing Signal Strength and marking both
Poles.
• Mark the first Pole location found with a red triangu-
lar Pole marker. After centering on the Pole, a double-
line indicator will appear. This line represents how the
Sonde is lying underground, and in most cases also
represents the pipe's approximate direction.
• When the locator gets close to a Pole, a zoom ring will
appear centered on the Pole, allowing precision cen-
tering.