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OKM metal detector field test conducted by German expert

During the field tests of OKM's metal detection technology (also known as the „Future Series“) several real-world tests were conducted by Dr. Karl-Heinz Walker. He is an independent physicist and technical expert for measuring and sensor technologies as well as a publicly certified and sworn expert of the IHK Karlsruhe (Chamber of Industry and Commerce).

All field tests were executed between 14th and 18th of July 2006. We supplied two of our best selling products, the eXp 4000 as well as the Future 2005, to be reviewed by Dr. Walker, who picked some of the named devices by chance. The main reason for these reviews was to test the general trustworthiness and repeatability of the implemented detection technology we are using in our metal detectors.

With all the selected products, following tests were conducted:

  • Metal detection of several metal objects (iron, aluminum, gold)
  • Detection of underground voids (tunnel, plastic barrel)
  • Reliability and performance tests (nearby detection, scan resolution, target depths)

After testing our OKM metal detectors on different sites and under various environmental conditions the technical expert Dr. Walker presented a final field test report and issued an official signed certificate.

Detection of aluminum cases in different depths

For this field test several aluminum cases were buried in depths of 0.5 m, 1.0 m, 1.5 m and 2.0 m to find out the reliability of detecting nearby non-ferrous metal objects. Many weeks before the actual field review took place, we dug in all test objects. Thus the surrounding soil could settle down and the disturbance of the destructed ground was less influencing.

Dr. Walker used the metal detector eXp 4000 to examine the target area. The most interesting question was if he could separately see the single objects or if it will appear as one big anomaly only.

Preparation of the aluminum cases
Preparation of the aluminum cases
Long time before the actual field test began we have buried 4 aluminum cases in different depths.
Graphical representation in Visualizer 3D
Graphical representation in Visualizer 3D
All 4 aluminum cases are clearly visible in the recorded scan image.

The recorded scan image looked very promising because the four hidden objects could be separately identified. One of the essential aspects we confirmed with this experiment is that long term buried objects are much better detectable than quite recently buried items.

Detection of underground tunnels

Not only can the OKM detectors find underground metal objects but also hidden tunnels, caves and voids as another field test proved. The expert's testimony was conducted in the city of Altenburg where an ancient vault (water channel) is existent. This tunnel is about 6 m under the street level and has a width of 1 meter. Over many decades this channel is the overfall of the city's pond.

This location was quite good to test the capabilities of our detectors regarding void detection. On top of the tunnel is a large metallic balustrade that could easily influence the measurement. Therefor Dr. Walker kept a certain distance to it to avoid detecting the railing itself.

Underground tunnel
Underground tunnel
The vault that is used as overfall for the city's pond is about 6 meters under the ground surface. We kept a good distance to the metallic balustrade to avoid its influence.
Scan image of hidden tunnel
Scan image of hidden tunnel
The final scan image that was recorded with the eXp 4000 metal detector generated a nice three-dimensional graphical representation. The blue color indicates the actual tunnel system.

The geophysical scan was conducted right above the hidden structure where a concreted street and a paved sidewalk is situated. The eXp 4000 metal detector was used in the parallel scan mode to receive the most precise measuring data. The resulting scan image, that was transferred to our Visualizer 3D analysis software, showed the underground tunnel very nicely.

According to the colored graphical representation the subsurface tunnel system was exactly where it was supposed to be. We could even see the slight bend of the tunnel. Additional measurements confirmed the existence of the vault and proved the repeatability of OKM's detection technology.

Detection of buried gold bars

One very important test review was prepared with buried gold bars to test the gold detection capabilities of our metal detectors. This experiment was specially designed for all treasure hunters and gold seekers that use our products to find buried precious metal objects (e.g. gold, silver, copper and bronze). Therefor we placed gold bullions in different depths to also check the depth measurement capabilities accordingly.

Detecting buried gold bars
Detecting buried gold bars
The test field was prepared with gold bars in various depths to check the metal detection capabilities of the detectors.
Scan image of gold bars
Scan image of gold bars
The resulting scan image of the gold bullion test review clearly shows the detected object in red colors.

Like all other field tests also the gold test was successful and the implemented detection technology was able to detect the buried gold targets. The indicated depths varied just slightly but give a good estimation of how deep the treasure hunter must dig to find the artifacts.

After successful completion of all field tests Dr. Walker prepared a final test report with all testing results as well as a field test certificate. This practical inspection proves the operability and reliability of the “Future Series” detection technology in our metal detectors and 3d ground scanners. All OKM products are solely manufactured in Germany and will be improved continuously to reach deeper targets, find smaller objects and provide more accurate measurements.


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