F3 INSTRUCTOR NOTES
Minelab Countermine Division Safety Through Excellence
33
Once completed, the student should be able to indicate the centre of the target, or
where there are several targets close together, the student should be able to outline an
area that is considered dangerous.
• Two targets resolution. The aim here is to show how to map two targets laid within
close proximity to each other showing the actual shape on the ground of the dual
targets. By moving the coil slowly over both targets, if may be possible to hear two
tones representing two targets. This will depend on the distance of separation between
the targets.
• Similar looking targets but opposite tones. This demonstration can be achieved
using two coins that look similar but react differently to each other (eg. a US dime and
an Australian 5c). This is to demonstrate how the tones can provide some information
about target conductivity. For example the coins, although they look the same they are
different in composition. In some demining programs this feature is used to help identify
specific mines. For example, a VS50 sounds much different than a Type 72.
• Large Target. For a large metal target such as a metal anti-tank mine the edge of
detection will be detected much sooner than a target with little metal content. In turn the
mapped “danger” area will be large. To reduce this area the coil should be lifted from
the ground and the mapping procedure should be repeated. As the coil is lifted further
from the ground, the “danger” area will be substantially reduced thereby making it easier
to locate the center of the target. However, it must be pointed out that a large target
may mask a small target (eg a booby trap). Where there is any suspicion of booby
traps, it is strongly recommended that excavation of the mapped area commence on the
original mapped area and not the reduced mapped area.
• Water. Dig a hole and fill it with water (or use a plastic bucket without a metal handle)
and show the F3 coil is not affected by operating in a wet environment.
• Soil sifting. The closed Monoloop Coil offers an excellent method when searching an
area for a target. Rest the coil on a known clean piece of ground close to the area to be
excavated. As soil is removed take a handful and allow the soil to gently fall onto the
coil top. If no response occurs brush the soil off and do it again with another sample.
When presenting this demonstration ensure a small piece of metal is placed into the
area to be excavated. Initially, show the students the detector alarming on a target in
the ground then proceed to find it using this process.
OPERATOR CONFIRMATION EXERCISE
The Operator Confirmation Exercise is used to confirm all training objectives for the course.
Instructors can decide to what degree the exercise can take. For example, it can include a
theory evaluation with oral questions being given to the student. However, as a minimum
each operator must demonstrate proficiency in the use of the detector by entering a
previously prepared test area.
For an operator to be deemed proficient, all targets within the test area must be detected.
If a student fails to detect all targets, he should be permitted to attempt the Confirmation
Exercise as many times as necessary in order to pass.
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