Pinpointing; Detection Range; Target Size And Depth - C-SCOPE PROMET3 Operating Instructions Manual

Pinpointing
Since the detectors employ a Total Response search head the object can be
detected across the full width, back to front, of the search head. Maximum
sensitivity occuring down the middle of the search head.
(i) The strongest signal will always be received when the object is directly
beneath the centre of the head (see X in Diagram 1). To pinpoint the find,
stop the search head when you are directly over the target object, then move
the search head through 90" and sweep again, thus forming a cross with the
two sweeps.
(ii) To 'focus' the target signal further raise the search head, retuning if
necessary, and pass the search head over the object until only a faint signal
is heard.
The faint signal will then be occurring at point X under the centre of the head.
More accurate pinpointing, particularly of deeply buried objects can be
achieved by finding the centre of the target object as described above and
fixing its position in the 'minds eye'.
Turning your detector through 90" and sweeping across the target again will
give a second reading, accurately determining the centre of the object.
Digging carefully at point X will reveal the find. With little practice, size, shape
and depth of an article may be estimated in this way before digging.
Detection Range
Determining the
Target Size and
Depth
DIAGRAM 1
Detection ranges will vary depending on the size of the object, the length of
time an object has been buried, and the type of ground the object is buried
in.
The best ground conditions are well compacted soils and coins can be found
at the greatest depths if the object has been buried for some time and the
coin has interacted with the salts in the ground, thereby appearing larger to
the detector. The worst conditions for detecting are on loosely compacted or
freshly dug ground or when the object has only recently been buried. In
these conditions detection range will be reduced. 90% of all artefacts are
found within 6" of the surface.
N.B. Adverse soil conditions can reduce depth of detection by more than half.
An operator who is familiar with his instrument will be able to do an excellent
job of determining object size, shape, and depth before he digs. This
technique is learned from careful analysis of the audio signals coming from
the detector. Each time a signal is heard, listen for any peculiar
characteristics it may have, determine over how large an area you get a
detector signal, and try to "outline" the object before you dig. Listen for the
sharpness or dullness of the signals and determine the magnitude of strength
of the signal. A coin for example will have a sharp signal, a nail a fuzzy
signal.
After digging up the object, compare the object size, shape, depth and
position in the grouno with signal information you received before digging.
After careful analysis of many digs, you will learn to "read" the hidden target
before digging.
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