RIDGID SeekTech SR-20 - Manual (Page 12)

Ridge Tool Company 
Tools For The Professional TM
seekTech sR-20
Operating Tips for Active Line Tracing
• The SR-20 quickly identifies distorted fields. If the
guidance arrows are centered on the screen, and the
Trace Line is not centered (or if the Proximity Signal
number and Signal Strength are not maximized), then
distortion is creating a complex non-circular field.
• To improve the tracing circuit:
a) Try changing the frequency used to a lower one.
b) Move the ground stake position away from the line
to be traced. Use a larger ground contact surface
(e.g., a shovel blade).
c) Make sure that the line is not commonly bonded to
another utility. (Undo common bonds only if safe to
do so).
d) Move the transmitter to a different point on the line,
if possible.
• If the Tracing Line will not center or if it moves across
the screen erratically, then the SR-20 may not be
receiving a clear signal. The Measured Depth and the
Proximity Signal may also be unstable under these
circumstances.
a) Check the transmitter to be sure that it is operating
and well grounded. Good connection and good
grounding overcome low current problems.
b) Test the circuit by pointing the lower antenna at
either transmitter lead.
c) Check that the SR-20 and transmitter are operating
on the same frequency.
d) Try different frequencies, starting with the lowest,
until the line can be picked up dependably. Using
lower frequencies can overcome bleed over
problems.
e) Relocate the ground connection for a better circuit.
Ensure there is enough contact (ground stake is
sufficiently deep) especially in dryer soils.
f) In extremely dry soil, wetting the area around the
ground stake will improve the circuit. Be aware the
moisture will dissipate and evaporate, reducing the
quality of the circuit over time.
• Using the numeric Signal Angle Indicator is another
way to check for distorted signals.
Move the SR-20 perpendicularly to both sides of the
traced line until the numeric Signal Angle indicator reads
45 degrees. Be sure to keep the lower Omnidirectional
antenna node at the same height, and the locator
mast vertical. If there is little or no distortion the traced
line should be in the middle and the distance to each
45 degree point should be approximately the same on
either side. If the signal is undistorted, then the distance
from the line center to the 45° point is approximately
equal to the depth.
Another variation of this technique is to move the same
distance to the right and left of the traced line, say
24 inches (60 cm) and check that the Signal Strength
readings are similar.
Figure 22: Checking for Distortion
• While tracing, the Proximity Signal and Signal Strength
should maximize, and the Measured Depth minimize, at
the same place where the guidance arrows center on the
display. If this is not the case, the utility may be changing
direction or other coupled signals may be present.
• Higher frequencies bleed over to adjacent utilities more
readily, but may be needed to overcome breaks in
tracer wires or go over insulating couplers. If the line is
ungrounded at the far end, higher frequencies may be
the only means to make the line traceable.
• When using the transmitter inductively, be sure to begin
the locate about 30 feet (10 m) away to avoid “direct
coupling” (also know as air coupling).
Ground
Energized Pipe
= Same distance