35
Chapter 5 DFX
™
Pro Options
12. Fine G.E.B.
FINE G.E.B. is used to make smaller adjustments
to the Ground Balance range on either side of the
COARSE setting. The FINE setting combines with
the COARSE setting to determine the actual
ground rejection level. To determine exactly what
level the automatic Air/Ground sequence selected,
it is necessary to check both COARSE and FINE
levels.
Manual Ground Balance will rarely be used for
perfect balancing as the automatic balance is
extremely reliable. It is generally used to offset
Ground Balance for the same reasons AUTO
TRAC
®
OFFSET is used.
In COARSE or FINE, lower numbers indicate a
Ground Balance setting toward the negative side of
the V.D.I. scale (iron). Larger numbers indicate a
Ground Balance setting toward the positive side of
the V.D.I. chart (salt). Bad ground conditions
(high mineralization) may be described as either
magnetic (negative or low numbers) or conductive
(positive or high numbers). COARSE and FINE
settings of 0 represent a ground rejection similar to
a V.D.I. number of -95. COARSE and FINE
settings of 255 represent a ground rejection level
similar to a V.D.I. number of +10. This V.D.I.
range from -95 to +10 represents the ground rejec-
tion range of this instrument. If ground balance
(either automatic or manual) occurs near the 255
COARSE setting, significant loss in sensitivity can
be expected to targets which indicate in the V.D.I.
number range of 1 to 10. However, manual ground
balance doesn't exactly work like a discriminator,
where V.D.I. numbers are simply REJECTED.
The actual phase of Ground Balance is out of
sequence with most targets; thus some responses
will occur even if COARSE & FINE G.E.B. are
matched exactly to a particular targets V.D.I.
number.
128
FINE G.E.B.
MIN
MAX
(G.E.B./Trac section)
Tips - Use for controlled
reactions to specific
minerals or hot rocks. The
Fine G.E.B. control when
adjusted to the top of the
scale, 255, will automati-
cally bump up the Coarse
G.E.B.
setting by one
increment so that fine
adjustment can continue
uninterrupted. When
adjusted to the bottom of
the scale, 0, Coarse G.E.B.
setting is automatically
bumped down by one
increment so that fine
adjustment can continue
uninterrupted. The entire
Coarse G.E.B. range is
available on the Fine
G.E.B. control made
possible by this mecha-
nism. Settings from 0-255
are available, coarse and
fine.
