Manual

Figure 6. Raising the Locator Eliminates Unwanted Signals
Strongly Magnetized Markers
A strongly magnetized marker at or near the surface may provide location information that is misleading.
The heavy line in Figure 7 represents the variations in tone frequencies when the locator is moved over the marker. When moving
the instrument from A to B, the frequency of the tone increases and then suddenly decreases at B. From just beyond B the frequency
of the tone increases sharply, becomes very high directly over the marker and decrease just before reaching C. From C to D the pat-
tern is the reverse of that from A to B. It is obvious that the locator must enter the B-C region. Otherwise the marker might be assumed
to be between A and B, or C and D.
Figure 7. Signal Pattern From a Strongly Magnetized Marker
SMALL BOLT
CORNER MARKER
SIGNAL AT GROUND
SIGNAL ABOVE GROUND
Schonstedt Instrument Company 4