User's Manual

Locating
DigiTrak
®
F5™ Operator’s Manual 71
NOTE: If the transmitter pitch exceeds ±30% (or ±17°) and/or the transmitter depth exceeds 15 ft (4.6
m), the position of the locate line will be somewhat ahead of or behind the transmitter’s actual
position. In these cases, the depth displayed on the receiver is referred to as the projected
depth (see Appendix B for more information regarding this situation).
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 the
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
70°
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.
Drill
Surface of
ground
Transmitter (negative
or downward pitch)