Mine action specialist
introduces metal-detection in Humanitarian Demining,
NOT mine detection. The use of dogs and other means of
detection that may be used to find explosives are introduced
Humanitarian Demining is done manually, using metal-detectors
as a primary detection tool. For detailed procedures actually used in the field, see Chapter 6 of the Global SOPs or Metal-detector use.
detector is a Schiebel AN-19.
Schiebel AN-19 was once the industry standard metal-detector.
old Schiebel was still in use in Syria in 2015. In easy soils and
looking for the right mines, it still has its uses - and many
commercial companies retain their old detectors for use when
possible - keeping newer models for more difficult areas.
the old Schiebel AN-19 and its Mod7 version are still widely
used - they are not robust and not appropriate to search for minimum metal targets. This
picture shows broken Schiebels in Africa - all of which are
uneconomic to repair. Cables and head-hinges have broken and
the surface of the head has worn against the ground exposing
length of the detector that is favoured varies dramatically,
and depends on how the tool is used. A detector that has a battery
that must be worn on a belt can make it impractical to use a
one-man drill. (In a one-man drill, the man with the detector
also kneels down and excavates any signals he gets.) The man
on the left is using a Vallon, the one on the right, an Ebinger.
use a detector that can only be used standing - which does not
always mean that they use a two-man drill.
Afghans attached the Schiebel AN-19's battery to the detector
shaft so that they could use a one-man drill.
detector is placed behind him while he excavates.
Vallon has the battery attached to the handle and an expandable
pole. Most modern detectors allow the length to be adjusted.
man is also engaged in a one-man drill. He has propped a long
detector beside him as he investigates a reading.
prefer to work kneeling all the time, even while detecting.
In this case, the detector is held vertically. There
is some evidence that the angle of the detector head to the
shaft can alter some detectors' performance.
detector in the last slide was an Ebinger 420SI. This is an
Ebinger 420GC, but it looks the same. What seems to be a side-handle
is actually a speaker. In
GC mode, this particular model of detector's ability to detect at depth may be significantly reduced.
detectors may also be used standing. This deminer is using an
Ebinger 420 under power lines. The
effect on performance of electromagnetic disturbance from power
lines, substations or radio broadcast facilities can be profound.
So can the proximity of one detector to another during use.
detector was the popular Ebinger 420 - more popular for its
robust reliability than its great performance. That
said, models of detector without a ground-compensating capability
can sometimes be used in areas with electromagnetic soils. They
may signal continuously, but the signal may vary where there
is a ground anomaly such as a lump of metal - or even the presence
of a buried non-metallic itemů. although the latter should never be relied
on. If a check is made using the anticipated target in the difficult
ground and the deminer can understand the detector's varying
signal - it may be appropriate to use the detector anyway.
may be other reasons to use a long detector. For example, this
is in Cambodia - and the deminer is using his detector among
is because the bamboo has a value for the local people so must not
be cut. Ground conditions and the angle of an incline may also
dictate working in an upright position.
deminer in the bamboo was using a MineLab and in this picture
I am being trained to use the MineLab detector in Cambodia.
model had an effective ground-compensating feature but real
design weaknesses so that it was too easy to break. The later
MineLabs have overcome these problems.
MineLab F1A4 could also have the battery box attached to the detector
MineLab F3 is a very different looking beast - and much
easier to work with. Its handle expands easily and snap-on colour-coded endcaps adjust sensitivity. There is evidence that it is the best detector in terms of its ability to 'compensate' out the sound of electromagnetic disturbance in difficult ground without a significant reduction in search depth. It is the detector that I have bought for use in any country - its only downside is that it uses more battery power than some other detectors.
is a modern Foerster Minex and the old Schiebel side by side - showing
how the ergonomics has moved on. The electronics inside have
sometimes changed just as much. I have had personal experience (in Angola) that the Foerster Minex's build quality is not robust, with hundreds of models unusable after a few months of use - and no advice directly available from the manufacturer despite the request being made through UNDP.
is the Schiebel ATMID, Schiebel's updated offering.
And below is the Guartel. Their
Guartel MD8 was interesting, but many people did
not understand the effect of using a large head to find shallow
targets in difficult soils, or the advantages and disadvantages
of its 'double D' search-head. Some
had high hopes of the Guartel Mini-8 (A4 sized), but I have never seen
one in use. [An A4 sheet is around the same size as a US letter-size
sheet of paper.] Small is attractive - because it means less
weight - but the detector must still be robust and able to find
Minelab have achieved this with their 'compact' F3 detectors, the picture shows one folded and one partly expanded. They can be used at any length and their construction is robust.
are many models of detector, with MineLab and Vallon apparently leading the field with their latest models that are
able to detect at depth in electromagnetic soils. Ciea and Schiebel has
also made advances and I believe that Ebinger is a real contender,
but Guartel have long since ceased production (although a copy has been offered for sale recently).
- and getting the best from a particular model in the field
- are large subjects requiring a good knowledge of demining
needs, and some knowledge of how detectors work. These subjects
are covered in the Metal-Detector Handbook. For a more detailed introduction to their use, or Metal-detector use.
For detailed metal-detection procedures actually used in the field, see see Chapter 6 of the Global SOPs.
Return to Introducing demining.