Location Methods, Localize the sonde

SeekTech SR-60

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-60 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 34: 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-60 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-60 so the mast is pointing outward. Sweep the antenna mast in the suspected direction of the Sonde while observing the Signal Strength and listening to the sound. The signal will be highest when the mast is pointing toward the Sonde.

•Lower the SR-60 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-60 close to the ground over the high- signal point. Be careful to hold the receiver at

Figure 35: 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 maximum 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 maximum 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.

Ridge Tool Company Elyria, Ohio U.S.A