Ridge Tool Company
13
NaviTrack
®
II
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 NaviTrack II so the antenna mast is pointing
outward. 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 NaviTrack II 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 NaviTrack II close to the
ground over the high-signal point. Be careful to hold the
receiver at a constant height above the ground, as dis-
tance affects Signal Strength.
• Note the Signal Strength and move away from the high
point in all directions. Move the NaviTrack II 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 22 – 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.
If a Pole appears before the Equator appears, localize the
Sonde by centering the Pole in the cross-hairs.
Step 2: Pinpoint the Sonde
The Poles should appear on either side of the max-
imum 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
locator 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 triangular
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.
• The second Pole will be a similar distance from the
Sonde location in the opposite direction. Locate it in the
same manner and mark it with a red triangular marker.
• If the Sonde is level, the three markers should be
aligned and the red Pole markers should be similar dis-
tances from the yellow Sonde marker. If they are not,
a tilted Sonde may be indicated.
(See “Tilted Sonde”
on page 14). It is generally true that the Sonde will be
on the line between the two Poles, unless there is
extreme distortion present.
Step 3: Verify the locate
• It is important to verify the Sonde’s location by cross-
checking the receiver’s information and maximizing
Signal Strength. Move the NaviTrack II away from
the maximum Signal Strength, to make sure that the
signal drops off on all sides. Make sure to move the
unit far enough to see a significant signal drop in each
direction.
