Manual Ground Adjustment; Headphone Jack / Using Headphones - Fisher F44 Owner's Manual

MANUAL GROUND ADJUSTMENT

to be inaccurate. If you stop moving the searchcoil, the bar graph will go blank.
INDICATION % Fe
4 Bars -High
3 Bars -Medium
2 Bars -Low
1 Bars -Very Low
None - -
Magnetic susceptibility is expressed in micro-cgs units. In a salt water environment
in the absence of iron minerals, the bar graph indicates relative electrical
conductivity.
In soils with greater than 4,000 micro-cgs units magnetic susceptibility, the
signal from the soil may saturate ("overload") the circuits. This will not harm the
detector but the machine will not be usable in that condition. The solution is to
hold the searchcoil several inches above the soil surface so it isn't "seeing as
much dirt". By listening and watching you will know how high you need to hold
the searchcoil in order to avoid overload.
The highest magnetic susceptibilities are usually found in soils developed over
igneous rocks, in alluvial 'black sand" streaks on beaches, and in red clay soils
of humid climates.
The lowest magnetic susceptibilities are usually found in white beach sands of
tropical and subtropical regions, and soils developed over limestone.
HEADPHONE JACK
This detector has a 1/4" headphone jack. It works with any stereo headphone
(not included) that has a 1/4" plug. When the headphone jack is connected,
O SUSCEPTIBILITY
3 4
0.4 - 1.6
0.1 - 0.4
0.025 - 0.1
0.006 - .025
less than .006
speaker volume is disabled.
headphones extends battery life and
prevents the sounds from bothering
bystanders. Headphone use also facilitates
detection of the weakest signals.
For safety reasons, do not use headphones
near traffic or where other dangers are
present. This device is to be used with
interconnecting cables shorter than three
meters.
The headphone jack has a rubber plug that will
help keep foreign material from entering the control
box. To insure it remains weatherproof, do not use
headphones during rain or very wet conditions.
Continued)
1,000 - 4,000
250 - 1,000
60 - 250
15 - 60
less than 15
Using
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