Searching; Narrow Scan Inductive Search; Set Up - Fisher Gemini-3 Operating Manual

SEARCHING

Narrow Scan Inductive Search

This mode of operation is performed by a single operator using
the 3-piece handle. It is the best method for locating small or short
objects (chest, coin-jar, rifle, etc.). However, it is also an effective
way to locate pipes, cables and ore veins.

Set Up

1. Assemble the 3-piece handle by inserting each
end piece into the center handle section. Tighten
the two center knobs finger tight until there is no
wobble. Place the transmitter on its back and
insert the end of the handle with the single brass
shaft into the V-shaped slot. Turn the knob until it is
finger tight and the handle is firmly in the slot.
2. Align the receiver panel holes with the upper-
handle threaded shafts. Tighten the lower black
knob until it is finger tight.
3. Turn the balance knob (with white arrow) until the
spring is under tension (at least 10 turns).
Figure 5. Assembly for Narrow Scan Inductive Search
Figure 4. Narrow Scan
Inductive Search
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PROSPECTING TIPS
Mapping
When an area of high conductivity is encountered,
outline and stake it by crossing and re-crossing,
using the Narrow Scan Inductive Search mode. It
will be noted that in and near the conductive zone,
a maximum indication will be received in only one
definite direction when the operator stands at one
point and rotates the instrument parallel to the surface
of the ground. Record the meter readings as read
in the maximum directions, at various points along
the zones. Note the character of the overburden,
outcrops and topographic features.
When the area being inductively surveyed has been
completely covered and all of the conductive zones
have been staked, these zones are surveyed and
plotted on a map. The map should include all creek
bottoms, gullies, outcrops and other physical features.
The ideal map on which to plot the conductive zones
is a topographic and geological map of the proper
scale. In this way it is possible to correlate the zones
directly with the topography and geology, and thus
determine the possible reasons for the presence of
the various conductive zones.
Locating Placer Deposits
A lot of prospectors have told us they would like to
use a two-box for locating placer gold. In general,
these deposits contain such a small amount of gold
that it cannot be detected. Placer gold, however,
is usually associated with a certain amount of black
sand, and some placer deposits carry iron sulphide.
Both of these mineral substances are definitely
conductive, and may be detected by the GEMINI-3.
It is through the detection of these minerals that the
placer gold may be located.
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