User's Manual

Locating
DigiTrak
®
SE™ Operator’s Manual 45
Effects of Depth, Pitch, and Topography on Distance
Between FLP and RLP
In general, the deeper the transmitter is, the further apart the FLP and RLP will be. The distance between
the FLP and RLP with respect to the location of the LL is also a function of the transmitter pitch and
topography. (For more information, see Appendix B.)
When the transmitter pitch is negative, the FLP will be further from the LL than the RLP (see figure
below). When the transmitter pitch is positive, the RLP will be further from the LL than the FLP. If the
ground surface or topography slopes significantly, the locations of the FLP and RLP will also be affected
with respect to the LL even if the transmitter itself is level.
LL
FLP
RLP
Axis Line
Drill
Surface of
Ground
Drill
LL
Transmitter (Negative
or Downward Pitch)
FLP
RLP
Bird’s-Eye View
(Looking Down)
Side View
Transmitter (Negative
or Downward Pitch)
Effect of Pitch on Distance Between FLP, RLP, and LL
Note how the RLP and FLP are at different distances from the LL when the transmitter is at a negative
pitch (compare with figure on previous page in which the transmitter is level).
It is possible to calculate depth (for comparison to the receiver’s depth reading) using the distance
between the locate points and the pitch of the transmitter. For additional information, see Appendix C:
Calculating Depth Based on Distance Between FLP and RLP.
It is also possible to track the locate line when walkover locating is not possible, such as when surface
obstructions exist or interference occurs. For more information about this feature, called off-track locating,
see “Off-Track Locating” at the end of this section.