White’s Electronics Surfmaster DualField - Manual (Page 7)

7
PINPOINTING
A TARGET BY
"X"ING
CONSTANT 3-5 FOOT PER SECOND
OVERLAPPING SWEEP
WITH THE LOOP LEVEL, 1" ABOVE THE
GROUND
Chapter 4 Surf Dual Field Operation
The sweep speed affects the performance capabil-
ity of the detector. If you sweep too slowly, the
S.A.T. will attempt to tune out a detected target.
The result will be a loss in depth. If you sweep too
quickly, the detector may not respond to a detected
target also resulting in a loss in depth. The opti-
mum sweep speed is three to five feet per second.
In other words, if you sweep the loop in a five foot
swath in front of you, you should be able to count
“one-hundred-and-one.”
You may wish to bottom scrub the loop for maxi-
mum depth. Scrubbing is not really necessary and
may cause false signals over highly mineralized
sand/silt. Scrubbing also causes wear on the bottom
of the coil and puts added stress on the coil con-
necting hardware. If you wish to scrub, you should
purchase a protective loop cover. Be sure to remove
the cover at regular intervals and clean out any sand
or water.
The search coil has a very wide scanning area.
When you hear a target, sweep slowly over it until
the response is equal as you move the loop back
and forth. Pinpoint by sweeping it from two direc-
tions, from back-to-back and side-to-side until the
response is equal in all directions. If you slow the
sweep, you can pinpoint with a good degree of ac-
curacy. The most sensitive area of the loop is in the
center.
Shallow targets can be difficult to pinpoint if they
overload the coil. Simply raise the loop while “x-
ing” the target area. Coins lying flat will usually
respond best in the exact center of the loop. Coins
on edge, nails and irregularly shaped objects may
tend to pinpoint near the outer edge of the loop. If
you have trouble locating the target, turn the loop
90 degrees and pinpoint with the edge.
If you are searching an area
that has produced valuables, or
has the potential for producing
valuables, cover the area at least
twice. Search first in one direc-
tion and then again at a different
angle 90 degrees from the first.
Some targets, such as coins on
edge, may only respond from
one direction.