RIDGID SeekTech SR-20 Manuel De L'opérateur page 15

Inductive Mode: The transmitter is placed over the
conductor per Manufacturer's Instructions. The inter-
nal coils of the transmitter generate a strong field through
the ground which induce a current on the underground
conductive lines within the vicinity.
IMPORTANT! If the transmitter is too close to the
SR-20 in this mode, it can cause "air-
coupling" which means the locator is
reading only sign from the transmitter,
not the target conductor.
2. Observe the Proximity Signal to ensure that the
receiver is picking up the transmitted signal.
The Proximity Signal should peak over the line and
drop off on either side.
3. When tracing, the direction the pipe or cable is
running will be shown on the screen by the
Tracing Line. The Tracing Line will be a clear, sin-
gle line if the field being detected is undistorted.
Figure 20 – Tracing Line Showing Low Distortion
The Tracing Line has three important functions. It rep-
resents the location, and the direction, of the signal
being traced. It reflects changes in direction of the target
utility — when the utility makes a turn, for example.
And it helps recognize signal distortion. It does this by
becoming cloudier as distortion increases.
Figure 21 – Tracing Line Showing High Distortion
Use the Guidance Arrows, Proximity Number, Signal
Strength, and Tracing Line to guide the line trace.
These pieces of information are generated from discrete
signal characteristics to help the operator understand
the quality of the locate. An undistorted signal emitted from
a line is strongest directly over that line. In an undis-
torted signal, the Guidance Arrows should balance over
the crosshairs at the same time the line centers on the
crosshairs.
NOTE! Unlike the Signal Trace lines, the guidance ar-
Confidence in the accuracy of a locate can be increased
to the degree that the signal characteristics agree. If all
four agree, confidence can be high in the quality of the lo-
cate. If the trace line and the Guidance Arrows do not
agree, maximize the Proximity Number and the Signal
Strength. To the degree that Guidance Arrows, Maximum
Proximity Number–Maximum Signal Strength agree (are
all located in close proximity to each other), the degree of
confidence there can be in the accuracy of the locate.
Tracing Line
Figure 22 – High Probability Locate
Care should be taken to watch for signal interfer-
ence that may give inaccurate readings. The
Tracing Line is only representative of the position of
the buried utility if the field is UNDISTORTED. Do
NOT base a locate solely on the Tracing Line.
Always cross check the locate by ensuring that:
• The Tracing Line shows little or no distortion response
(blurriness).
• The Proximity Signal and the Signal strength maxi-
mize when the Tracing Line crosses the map center.
Tracing Line
• The Measured Depth increases appropriately as the
unit is raised vertically and the Tracing Line remains
aligned.
Measured Depth readings should be taken as esti-
mates and actual depths should be independently
verified by visual inspection prior to digging.
As always, the only way to be certain of the location of a
utility is through visual confirmation by exposing the
utility. The accuracy of position and depth measure-
ment improves as the SR-20 lower antenna node is
placed closer and closer to the target utility.
Ridge Tool Company
SeekTech SR-20
rows require that the user orient the locator so
that the guidance arrows point 90 degrees to the
Signal Trace line. (See Figure 20).
WARNING
Tracing Line
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