Minelab F3 Operation Manual page 36

F3 Operations Manual
a. STEP 1
Having detected a target and obtained a rough idea as to its size
and location using the sweeping procedure, the precise location
of the target can be "mapped" using the F3's "Edge Detection"
technique.
Edge Detection makes use of the coil's consistent sensitivity
around its circumference to detect the edges of a target. To
conduct edge detection, the coil should approach the suspected
location of the target from a variety of angles as shown in Figure
23.
As the coil approaches the target, the Threshold Tone will
change indicating that the coil is in close proximity to the target.
At the change of the Threshold Tone, the operator should
mentally mark the position on the ground, move the coil away,
and approach the target from another angle.
This process continues until the operator achieves a mental
picture of the target area.
Mapping the Target
Figure 23: Mapping the Target
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