Operating With The Distortion Line - RIDGID SeekTech SR-20 Operator's Manual

The two lines may also move randomly if a weak signal is
being received, indicating that the locator circuit needs to
be improved (see page 14 for tips on improving the signal).
The balance of the Tracing Line and the Distortion line
combine to give the operator much the same information
as the Tracing Line with its distortion response enabled,
but in a different graphical form. Advanced operators
may find this more useful in discriminating the primary sig-
nal from the impact of distortion.
Menu Tree
The graphic shows a summary of the options and controls
built into the SR-20 menus. Move through the choices
using the Up and Down Keys. Pressing the Select Key
when any choice is highlighted will show that sub-menu.
Activated Frequencies
Sonde
Line Trace
Power (Passive Trace)
Radio
Units of Measure
Feet/Meters
Backlight Options
On/Off/Auto
LCD Contrast
Increase/Decrease
Display Elements Select (Check On/Off)
Trace Mode Sonde Mode
Watermark
Signal Focus Setting
No-Signal Indicator
Sound Signals
Center Signal Strength*
Signal Strength
Proximity Threshold*
Signal Angle Indicator
Distortion Line*
Tracing Line Distortion Response*
Sound Mute > 99'
Guidance Arrows**
* = Line Trace Display Only
Frequency Select (Check On/Off)
Sonde
16 Hz, 512 Hz, 640 Hz, 850 Hz,8
kHz,16 kHz, 33 kHz
Line Trace
128 Hz, 1 kHz, 8 kHz, 33 kHz,
Power
50 Hzx1, 50 Hzx5, 50 Hzx9, 60 Hzx1,
60 Hzx5, 60 Hzx9, 100 Hz, 120 Hz, <4 kHz
RF
Low (4-15 kHz
High (>15 kHz
Information Menu
Figure 50 – Menu Tree
Restore Default Settings
(Check Yes/No)
Ridge Tool Company
SeekTech SR-20
Informational Locating
The normal shape of a field around a long conductor
such as a pipe or cable is circular (cylindrical in three di-
mensions). When over the center of a circular field, the
operator can observe the following indicators:
• Maximum Signal Strength
• Maximum Proximity Signal (Line Trace Mode)
• Centered Tracing line with minimized distortion
• Guidance arrows centered, agreeing with Tracing line
• Minimum Measured Depth
• Sound pitch and volume will increase until they max-
imize over the target utility.
Figure 51 – Over a Circular Field
Tracing a line which is near other large conductors
such as power lines, phone lines, gas mains, rebar, or
even buried scrap metal can lead to questions.
By comparing the Guidance Arrows, the Tracing Line,
Signal Strength, Signal Angle, Measured Depth, and
Proximity Signal, an operator can learn more about the
field being distorted. Comparing the field information with
an educated view of the ground, noticing where trans-
formers, meters, junction boxes, manholes, and other
indicators are located can help in understanding what is
causing field distortion. It is important to remember, es-
pecially in complex situations, that the only guarantee of
the location of a particular line or pipe is visual inspection,
such as by potholing.
Compound or complex fields will produce different indi-
cations on the SR-20 that will show what is happening.
Some examples might be:
• Disagreement between guidance arrows, Tracing
Line and Distortion Indicator
• Inconsistent or unrealistic Measured Depth signal
• Fluctuating random indications (also caused by very
weak signal)
• Inconsistent Proximity Signal compared to guidance
arrows (Active or Passive Line Trace modes)
• Signal strength maximizing off to one side of the
conductor.
Tracing Line
27