Detection Range
Your CS1220XD is a top performance detector but adverse soil conditions can significantly
reduce the depth of detection.
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 depth
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.
Determining the Target Size and Depth
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
meter and audio signal 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.
After digging up the object, compare the object size, shape, depth and position in the ground with
signal information you received before digging. After careful analysis of many signals you will
learn to 'read' the hidden target before digging.
Detecting
To test for the type of signal you will get, take a coin or metal object and with the detector set up
on a table tuned as previously described, move the metal object towards and across the search
head. You will note that the volume will increase quickly as the metal object passes across the
search head, with the loudest sound occurring when the search head is immediately centred over
the metal object. As the object passes beyond the search head the sound will quickly fade.
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 is down the middle of the
search head.
Pinpointing
(i) The strongest signal will always be received when the object is directly beneath the centre of
the head (see X in the diagram below). To pinpoint the find, stop the search head when you are
directly over the target object, then move the search head through 90
0
and sweep again, thus
forming a cross with the two sweeps as show in the diagram.
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