Searching - Fisher Labs M-97 Operating Manual

TUNING
Select an area that is free of metal near and under the search coil.
Turn on the M-97 by setting the Mode control to "Normal" and Ground
control to the position "5". Raise the search coil about 12 to 18 inches
above the ground (dirt, concrete, asphalt, etc.), and press and release
the Retune Button. Note any change of sound. If there is no change, or
only a slight change, the M-97 is balanced and ready to search.
If the sounds changes: Sound increases – Slightly decrease the Ground
setting. Repeat above procedure. Sound decreases – Slightly increase
the Ground setting. Repeat above procedure.Repeat until no (or a
slight) change of sound occurs.

SEARCHING

It is a good idea to establish a methodic search pattern. Avoid swinging
the M-97 like a golf club, swing the detector side to side keeping the
search coil the same distance above the ground. Your sweep pattern
should be a slow, half-circle motion. If you are searching for a small
target, it is a good idea to overlap your sweeps.
When the detector's search coil starts to pass over a metal object,
the sound will increase and the meter readings will increase. Depending
upon the size and depth of the target, the target may appear (respond)
to be larger than it should. To get a visual outline of the target, you need
to reduce the sensitive of the M-97 by raising the coil and passing over
the target. This can help establish the edges of the target.
Another method that will give a visual outline is to purposely detune the
M-97. Move the coil away the target. Slowly bring the search coil toward
the target. As the sound increases, press and release the Retune Button.
Continue to move the coil toward and eventually over the target. The
sound and meter readings will be more responsive as the search coil passes
over the target. You may need to repeat this step more times if the target
is at a shallow depth. Be aware that you can loose responsiveness of the
target by over reducing the Tuning Control (sensitivity) of the M-97.
To reset the M-97 back to the balanced settings, lift the search coil off
the ground, and away from any metallic objects and press and release
the Retune Button. The M-97 will automatically retune to the original,
balanced settings.
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