OKM eXp 4500, User Manual

Page: 93 / 94

Scanning Techniques 93
9.2 Control Scans
Always conduct a set of control scans on any area prior to excavation. A control scan is a very accurate
measurement to ensure that the area being prospected is a viable area and to verify that the target is
real. This is done by doing additional scans.
To ensure consistency of the scans the same person should do the scans, they should be done using the
same starting and the same stopping points. The control scans have the same amount of impulses and
the same amount of scan lines in every scan. Both methods, single line and conventional, need to be
conducted to ensure that the field of mineralization is correct. This is very important for it is easier to
conduct an additional set of scans rather than dig a hole with nothing in it.
In the example (illustration 9.4) the easiest way to conduct an initial control scan is to scan the exact
same line in both directions. This method is used when prospecting for naturally occurring mineral
fields.
This is done by doing the first scan completely. At the end of the line, either download the existing data
to the laptop or change to another control chip (only for certain detectors available). Many users will
have multiple control chips for their unit to conduct more scans over a given area without having to
download the data after measurement.
There is a couple of very important reasons, one, if the target moves then it is most likely an area
without a valid target and two, you can get a much better perception of the actual size or area of the
target.
Having the same person perform the measurements is important. This way the scans will be done
exactly the same, with the same speed and the same amount of impulses. It is important that others
watch the operator as the scans are being performed to ensure that no mistakes are being made and the
scan lines are straight. The other users need to ensure that the Super Sensor is not rotating or tilting
and that it is remaining the same height over the ground.
OKM GmbH
www.okmmetaldetectors.com
Illustration 9.4: Control Scan the same line in both directions.
A
B