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4.6 Using the 4810 Probe with the 480B for Pinpointing and Depth Estimation
The long, pointer like design of the 4810 Inductive Probe provides a much sharper Receiver response than
the standard Receiver antenna mounted on the Receiver housing. Because it can be easily held close to the
ground, the Probe provides greater accuracy, especially in the presence of adjacent conductors, for
pinpointing the location and estimating the depth of a conductor. The 4810 Probe works only in the NULL
method.
To estimate the depth of a buried conductor:
1 Locate and mark the position of the targeted conductor.
2 Plug the 4810 Inductive Probe into the AUX INPUT on the 480BB Receiver.
3 Turn the 480B Receiver SENSITIVITY all the way up and turn the RANGE to "HIGH". The thumb
knob on the 4810 Probe will then control the 480B Receiver sensitivity.
4 Turn the 480B Receiver MODE SWITCH to "ACTIVE".
5 Adjust the 4810 Inductive Probe SENSITIVITY as needed, keeping it as low as possible to sharpen the
Receiver response.
6 Use the same triangulation procedure as described in Section 4.5 Estimating the Depth of a Conductor.
Tilt the 480B Probe to a 45 degree angle as indicated by the bubble at the base of the Probe handle and then
move off to the side of the conductor. When the conductor is "located" a second time with the Probe at a
45 degree angle, mark the location on the ground. The distance between the two marks is equal to the
depth of the conductor. See Figure 4-6.
Figure 4-6: Estimating Conductor Depth with the 4810 Probe
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If your conductor is buried in the shoulder of a hill, compensate for this fact by subtracting "C" from
"A" and "B" measurement as shown in Figure 4-7.