RIDGID SeekTech SR-20 - Manual (Page 13)

Ridge Tool Company 
Tools For The Professional TM
seekTech sR-20
• While tracing, the mapping display operates best under
the following conditions:
1. The line is level
2. The SR-20 Locator is above the target utility elevation
3. The SR-20 antenna mast is held approximately
vertical
If these conditions are not met, pay close attention to
maximizing Signal Strength.
In general, if the SR-20 is used in a zone over the target
line within a sweep area of about two “depths” of the line,
the map will be useful and accurate. Be aware of this when
using the map if the target or line is very shallow. The width
of the useful search area for the map can be small if the line
is extremely shallow.
Measuring Depth (Line Tracing Modes)
The SR-20 calculates Measured Depth by comparing the
strength of the signal at the lower antenna to that at the
upper antenna.
Measured Depth is measured correctly in an undistorted field
when the bottom antenna is touching the ground directly
above the signal source and the antenna mast is vertical.
1. To measure depth, place the locator on the ground,
directly above the Sonde or the line.
2. Measured Depth will be shown in the lower left hand
corner.
3. A Measured Depth reading can be forced by pressing
the Select Key.
4. Measured Depth will be accurate only if the signal is
undistorted and the antenna mast is held vertical.
Testing for the consistency of the Measured Depth reading
can be done by raising the SR-20 a known distance (say,
12 inches (33 cm)) and observing whether the Measured
Depth indicator increases by the same amount. Small variation
is acceptable, but if the Measured Depth does not change, or
changes drastically, it is an indication of a “distorted” field, or
very low current on the line.
NOTE: In Active Line Trace or Passive Line Trace modes,
pressing and holding the Select Key will force a Measured
Depth reading and will force the Signal Angle indicator to
change to Current. If sound is set on, it will also recenter the
audio tone.
Current and Signal Angle Reading
The Current Strength (mA) and Signal Angle indicator
( ) in the upper right corner of the screen will display the
current detected on the traced line, in milliamps, when the
computed angle to the center of the detected field is less
than 35° and the SR-20 crosses the center of the field as
sensed by the guidance arrows.
When moving across the center of the field the current display
will “latch” the displayed current value (retain it in the display)
until the guidance arrows reverse again, at which point the
latched display will be updated. The update and latch cycle
occurs whenever the guidance arrows reverse.
When the angle to the center exceeds 35°, the Signal Angle
indicator will again replace the Current indicator, and the
display will show the computed angle to the center of the
detected field.
Clipping (Tracing Modes)
Occasionally the Signal Strength will be strong enough that
the receiver will be unable to process the whole signal, a
condition known as “clipping”. When this occurs, a warning
symbol
will appear on the screen. It means that the
signal is particularly strong. If clipping persists, remedy it
by increasing the distance between the antennas and the
target line OR by reducing the strength of the current from
the transmitter.
NOTE: Measured Depth Display is disabled under clipping
conditions.