View Full Version : Sensor for finding non-metallic objects
08-24-2005, 01:14 AM
Does anyone have any suggestions for finding non-metallic in the soil.
08-24-2005, 01:25 AM
That is a really open ended question. Non-metallic what? It would depend on what you were looking for...
Parallax Tech Support
08-24-2005, 01:53 AM
08-24-2005, 01:59 AM
Wow, non-metallic land mines?
You could just invert the output of a normal metal detector, and then you could detect everything that *isn't* metal.....
Parallax Tech Support
08-24-2005, 02:32 AM
I have two suggestions, Ground Penetrating Radar (GPR), and acoustic analysis. The first uses radio waves, the second uses sound waves. I don't have experience with either, so do some research on them. There are additional potential problems (especially with the acoustic method), mainly that you have a risk of detonating the mine if the system is designed improperly.
Even ceramic mines have traces of metal in them, because while the casing, explosives and even the detonator can be non-metallic (even the battery can be made out of non-metallic chemicals encased in plastic or ceramic) the wire connecting the battery to the detonator must still be made of metal. When carbon nanotubes can be commercially made into wire-like conductors, you may see completely non-metallic landmines, but that is in the distant future.
<edit> I forgot about the old school mechanically activated chemical detonators, so a completely metal free mine is possible with current technology </edit>
Post Edited (Paul Baker) : 8/23/2005 7:34:03 PM GMT
08-24-2005, 08:34 AM
Cool D -
Certain testing for de-mining is done without regard as to whether the physical mine is metallic or non-metallic. That gives you a more universal mthod of detection.
"Sniffing" is done, as with the "sniiffers" in some airport baggage areas, and certain very high security areas. Some of the "sniffer" processing utilizes the odors present in many explosives, and other "sniffers" detect the elemental properties chemically (like reacting to a phosphate radical). So too spectral analysis can also used if the mines are not too deep.
A very promising, but yet quite untested area of exploration, involves processing some of the flora (vegetation) in the area. Some trace amounts of the explosive compounds from within the mines will leech into the soil over time. Some of these trace chemicals are drawn into the flora along with their normal water intake. A small amount of the leaf or stem can be rather easily ground up and tested (on the spot and robotically) to see if the trace elements are present. If they are, you then have a "target area" which can be more thoroughly analyzed by other methods, or actually de-mined mechanically straight away. If the trace elements are not present, then you can move along a fair distance before testing again. Testing can take place in a 270 degree arc with a long arm, so a good amount territory can be easily examined with each sampling. I read about this technique within the last 3-6 months, and I don't know how far they've gone with actually implementing it. I honestly don't remember where I read about it however - sorry.