large mass detection system and cavities with a manufacturing model and rendering 2D.

[Funfinder]

Interesting detector, I heard already about it but I have not enough info.
For shure this GPR would be a good compromise concering the price.

the test-reports here:

http://easyrad.de/pages/produkte/testberichte.php

show those usual GPR zig-zag curves and grey wobbles (also see attached pix)

If someone already is pretty shure that there are massive structures under ground its ok and working.
But out in the untouched fields or woods or at larger areas?
And I can't find the info if its possible to look directly at the output-info-monitor while searching.
Even that massive cellar just gives a pretty weak signal distortion impression.
I'm shure that already different layers of soil or humus will cause special patterns which
easily can be misinterpreted.

This info here is also interesting:

http://easyrad.de/pages/faqs.php

approx. detection depths:

dry gravel and sand: 5 - 10m
saturated gravel and sand: 2 - 5m
wet gravel and sand: 2 - 3m
tight dry ground: 2m
tight wet ground: up to over 1m
rocks: 5m to over 10m
Dolomit or marbel: up to over 20m
usual water: 4m - 6m
salty water: 0m

A little bit problematic is that cavity does not shows up as black or white space
but only the walls create the reflection-distortions.

Personally I would recommend such devices only to profis and
I would work only with it, if it has live-screening while walking around with it.
And I think it needs alot test-sessions before real hunting.

Would be interesting to see what it detects if somebody walks over the
streets of a city! The underground cables, the canalisation, roots of trees,
cellar-rooms, lines where are pipes etc.
Or at old ruins or castles to check out where are the cellars, hidden rooms or bunkers.

But I guess someone has to walk and cover first at least an area of 20 x 20 meters with
the detector so afterwards he gets an image where the underground stuff starts and ends.
This would be very interesting but it's like working with a magnetometer incl. imaging software
which also afterwards shows some map with possible special structures.
However - whats missing is the live-search, dig and find something - excitement.
And even if it has a live-signal-window someone would not see whats before and behind
to be shure if the actual signal continues or is larger etc. and what it could mean.

Whats needed here is some selfextending 3D model on the monitor that maps live the already searched
path so someone can see directly if he walked over a continuing special signal structure!

I have no info how good it reacts on large metal masses but it may show pretty good
where ground-work-activities have been made or where are cavities at undisturbed soil.

So far my needs in hunting for cavities is pretty low or doesn't even exists
but perhaps sometimes I visit the Easyrad producer and test this detector.
Could be a very interesting completing counter-part together with a good
metal-detector to cover the whole ground-exploration spectrum.


personal facit:

needs really alot experience, works not everywhere, can cause very deep holes ,
not really useful to detect metal-objects, no or only restricted live-search possibility,
interesting to map large areas, pretty good for cavity if the signals are strong enough,
penetration depth strongly depends on the type of ground, for 2500 Euros I might buy
it to find special holes & cavities but not for over 4000 Euros, alot measuring of the field
and distances has to be done for afterwards locating exactly where the signals came from.

[bernte_one]

whats with easyrad they are prooved and work ok

http://www.easyrad.de/

http://easyrad.de/pages/kaufen/preisliste.php

[Funfinder]

There is a 100% method - using some exavator and water for washin away all the dirt.
That way also the pretty small gold-stuff can be found. But its a huge effort and often it destroys nature.

XR-71 plus magnetometer is not a reliable solution.
With homebrew P.I. you will not get far.

Nokta has nothing to do with OKM, OKM builts LRLs and magnetometer-toys (stay away from them!)
while Nokta formerly was the parallel-company to Makro Group, meanwhile they have joined again.

[tchou]

Hello,

Treasure hunting in depth is really a fascinating subject that although the thing and complex and I realize that in this area there is no 100% reliable method which is a shame but hopefully continue learn about it and you Mettes valuable advise (Thanks)
I detailed my research and I found several electronic scheme for the LF / VLF method for IP sniffer XR-71 (plus a magnétmètre) as some forum speaks with cavities detection.
For I am always against the schema search for ground radar, Jeosonar, Jeohunter deephunter and to be sure to understand and analyze their operation.
In the course of my research I met nokta brand OKM ... you know?

Theo

[Funfinder]

Your selection already is pretty good but please consider 3 things:

1. Working with a non-motion VLF detector requires a bit more experience,
and sometimes pressing the reset button to set it back into quiet mode,
especially if you work with very high sensitivity settings.
But of course its around 20-30% deeper than a motion-detector
and can detect into both directions, cavity and metal objects.
And of course the coil-size also really matters.
You can find more info about those detectors here in this forum.

2. The visual output of ground radars (30-300 MHz wave reflectors)
is far away from 90% reliable! I would give them a 40-60% rating.
They output all kind of crazy wave-lines on the screen and if those have
been caused by different-soil-layers or rocks and you interpret them
wrong you may end up digging 5m deep holes for nothing!

3. Those passive or active radio long wave detectors need alot of experience
and do not work everywhere. You may detect fat pipelines 1 meter below
good enough but I guess finding treasures and cavities with them
could become real tricky.

If possible try before you buy or start with some used and cheaper detector first
so you can find out if it really fits your needs.
And of course also youtube is full of clips that show many detectors in action.

Thx for your interest in deep treasure-hunting, it also really fascinates me.

[tchou]

Hello,

Thank you for this great link I'll start with an average depth (up to 3 meters) and metal objects large size (1 to 2 m in size) as you advise. To test the detector and learn how it reacts on the cavities I had cavities paragraph 2 to 1 meter deep (one without and one with scrap metal) so that side of it is good.
Following your details on magnetometers and réssisvité of system solutions I eliminate it for my project. I removed automatically LRL solution but thank you for telling me
For the 9000 cs csope it can detect a cavity 2 meters (this is the kind of thing I'm looking for with a 2D imaging output) .J'aurais have liked more information about land using radar waves 30 to 300 MHz and more particularly on homebrew projects.

So if I summarize for the detection of large mass and metallic cavities, the most reliable methods sound =>
The Jeosonar or Jeohunter or deephunter Makro Group (95% reliable)
The terrestrial radars (90% reliable)
method LF / VLF (to be determined)

Did I comprie and summary ??
A big thank you to you both for your answers that helps me a lot!
Theo

[Funfinder]

http://www.friese-electronic.de/ortungstechnik/lf-vlf-tf/einfuehrung/

Auch unterirdische Hohlräume, z.B. ausgedehnte Stollen und Gänge, lassen sich detektieren, vorausgesetzt ist allerdings ein entsprechend leitfähiges Bodenumfeld.

This means translated that also cavities, underground-ways and mines are detectable if the ground in this area is
EM-field interaction friendly enough, so the detector can show a good cavity contrast-value compared to the usual ground.

A very good link, perhaps you better try with such kind of detector to find very deep and large cavities, tchou.
But be warned, you will need heavy equipment like large drillers and excavators to verify the search-results.

Better reduce your risk and start with medium deep (down to 3 meters) and large metal objects (1 to 2m in size).
Pure cavity detection is relative hard compared with metal because of the smaller signalization difference.

About your questions:
Magnetometers per instance are very sensitive for deep iron-objects - if you search for them or if the target contains it also.
In such case you can forget about cavity but completly focus on the huge metal masses deep below.
Mainly such devices are in use to create ground plans of larger areas, so afterwards you see the walls, wells and
everything else that has made some influence on the magnetical field conditions there.
So perhaps this is exactly what you're looking for - if you know already promising locations.

Please check google for cs 9000 csope info and how deep or good it may detect cavity.

You also should create first some closed hole at mineralized soil so you can test the detectors there
and learn how it reacts on cavity.

Ground resistivity systems are expensive and special so you need alot experience first and
the electricity also can flow above the cavity or around it so you may see nothing.

Ground radars which use waves from 30 to 300 MHz also are very expensive (but there exist some
not so expensive homebrew-projects).
Those often have imaging output but depending on the ground it may be just wrong signals, too.

Raspberry PI will not find cavity and you need to built a pretty large coil for it for finding real deep stuff.

btw. a Warning: Don't let yourself seduce by so called LRL-detectors!
The producers of them claim that those will detect gold from 100s of meters but they never can prove this!
This crap is pure wasted money and we have a special forum for this junk here to warn everyone:

http://www.longrangelocators.com/forums/

Keep it realistic: with a 45-50cm coil you may detect a 50 x 50cm object at 2 meters depth
with a non-motion detector like the DeepHunter and some 1x1 meter object at 3 meters.
But only if you work very slowly and exact with such devices and if the ground is undesturbed
and without metal junk parts every few cm.
And with a 1 meter coil you may get 40-65% more depth, depending how close it is moved
over the ground and other factors.
And so one of the most important facts is that you know already beforewards pretty exactly where
is the treasure or find location, otherwise you can't work careful enough or it could take ages.

I think its a bad idea but:
Of course you also can walk very fast with a P.I. and 1m coil incl. magnetometer over the area,
or with one of those pure magnetometer results capturing devices, but depending on the region
the risk can be very high that you will get false signals and afterwards you will have alot work or
you waste really alot time and money to dig very deep useless holes...

So better first start with detection-methods you have some experience already. Good luck.

[bernte_one]

http://www.friese-electronic.de/ortungstechnik/lf-vlf-tf/

some devices with active and passiv method

[tchou]

Hello,

Thank you for your reply My priority is the search for cavities up to 5 meter maximum with optional search of large mass so if I understands the best solution is buying a Jeosonar or Jeohunter deephunter or to have a made reliable. But the idea of PI coupled with magnetometer with an imaging output software via a laptop or a smartphone Interesē me well even if you do specify that this method is not completely reliable. I accept your advice about the coil. By cons you say the 2 box system does not detect cavities but cs 9000 at csope do? It has a magnetometer? What do you think resistivity system with imaging software? Are they more reliable than PI has coupled magnetometer? Another question come to my mind at time and I admit to not having searched before. Is that it was made project based raspberry pi?

[Funfinder]

Salue,

it depends what finds you are searching for - size and depth.
Rendering is not that important but selecting out small finds from huge and deep ones.
So far rendering anyway is just a representation of EM-field-signals and no "x-ray picture".
It just can give you some idea of how the find may look like and how deep and big it is.

You can buy meanwhile for low selling-out prices The Jeosonar or Jeohunter from Makro Group , Istanbul,
which contains image 2D (Jeosonar) or 3D (Jeohunter) rendering but this is not the main important part,
it is the depth and coil size.

What really counts is a huge coil and that you have the conditions to handle it.
And you can use a 1 meter coil with both of these detectors, this is what counts if you look for "fat masses".
You either will need a second person to walk with the 1m coil over the areas or some plastic wheels device to drag it
over the ground.

If you have enough money the DeepHunter is the newest detector of those series which works with 45cm and 1m coil
and also can handle a very deep 45cm motion coil. But if you look for per instance 1 meter large metal objects buried
2 meters below you really should use at least the 1 meter coil.

You also can try a pulse-induction detector (but no cavity detection) with 1 m but if you are used to VLF
it will be easier for you to stick with this. Some cheaper solution also would be a Whites 2 Box detector
but it is not that deep and it will also not detect cavities,
while the mentioned Makro Group detectors are able to detect it,
but this also needs some expierience and at least medium mineralized soil to work.

If your main priority is cavity you also can try some magnetometers or PI coupled with Magnetometer with imaging software
output via laptop or smartphone but I have to warn you, not all "blue fields" will be cavity and all red ones are metal objects.
Those computerized magnetometers reacts also on mineralization conditions and other parameters so you
may get a real hard time by digging "magnetometer cavities" which in the end have been just a big failure message.

So my advice: Go for real huge and deep metal masses only with a detector that is able to handle a 1 meter coil.

[tchou]

Bonjour,
Tout d'abord je tien a m'excuser pour mon anglais approximatif ... Je suis francais et détecte depuis 10 ans avec plusieurs VLF. Je viens sur votre forum car il ma était conseillé par plusieurs amis car je suis a la recherche d'informations précises sur le meilleurs système de détection de grosse masse et de cavités avec un modéle de fabrication et un rendu en 2D.

J'ai déjà lu beaucoup sur le sujet mais j'aurais aimé avoir vos avis sur le meilleurs système pour ce genre de recherche ?

Merci d'avance.

Hello,
Firstly I was yours to apologize for my broken English ... I'm french and detects for 10 years with several VLF. I just look for yourself because I was advised by several friends as I am in search of accurate information on the best fat mass detection system and cavities with a production model and rendering in 2D.

I've read a lot about it but I would have liked your opinion on the best system for this kind of research?

Thank you in advance.