Penetration Capabilities of Magnetometers

[Sam Scafferi]

Dell said; "...It has been apparent that your years of mis-construsion and rhetoric against me is lacking in scientific data, facts and research, which you claim to pride your self in..."

What in the world are you talking about?

How much more scientific could Carl have been in his article about the VR-800? He did everything but analyze the plactic in the PVC pipe fittings and the metal in your L-rods.

Now you come up with this feeble attempt to somehow draw attention away from the VR-800 report ---why are we not surprised!!!

Also, I notice that my "simple question" remains unanswered.

Why is that????

And no, this IS NOT the proper forum to be carrying on this discussion.

[Charles]

Re: Free Unit???

I didn't go into detail because that really wasn't the point. Actually it became a try before you buy deal. Besides being intrigued with the fact that it really did seem to do something for me, I opened it up and found a real circuit board mounted with screws and such instead of glue so I decided to buy it. If I tell you who it was then you will want the same deal and I was asked not to tell anybody about this. Yes, I do believe he wanted to shut me up but he did it in a way I was comfortable with and it was a gamble on his part. If I had not been satisfied with the results, he ran the risk that his name would have been mud on the forums just like you do to Dell. Believe me, I gave Dell a lot of grief for a while but I backed off because it gets old beating a dead horse the way some of you do around here. This dealer didn't know me from Adam and I thought he must really believe in his product to take that gamble.

"Care to tell us who it was that was so benevolent?"

Your attitude causes even us honest people to not want to share or converse with you because we don't know when it will backfire on us. After being burned myself by you, you've tried it on the forums and privately and I don't want any part of it. I am currently finishing up the design of a boat towed metal detector with a built in GPS, an underwater altimeter, and a magnetometer with other equipment still only ideas on paper. When I get done, you can start bashing me too.

Charles

[Randy Seden]

Re: Fox Talk Detectors/Gold Detectors-The Jig is up!

Glad to be of service Dell. Check out the link below from Eric Foster's PI Classroom forum.


Click Here

[Sam Scafferi]

Re: Free Unit???

My attitude is, and has always been to seek out the truth about so-called electronic-assisted LRL devices, and expose the scams when uncovered.

I have gone about my research in an open and rationale manner, the same way that I have reported my findings and results.

If my legitimate questions to you, or anyone else who makes claims about their results or their products, is seen as "being burned" --then perhaps you or others really do have something to hide.

Tell me Charles, in your days of "doubt" and "skepticsm", before you were awarded a "try-it-and-if-you-like-it-buy-it-instrument", how did you go about conducting your research and gathering of facts???

Your last remark, ...about finishing the design of an instrument, and when it is done, I can start bashing it..., is quite asinine indeed, and is not something I would've expected from you.

I'm guessing that what ever it is that you are designing, will no doubt do what it is advertised to do, the same as any legitimate consumer product is expected to perform. If it fails to meet your advertised claims, then I suppose it would be logical that you could be questioned about your published claims.

If you want to label that as bashing, so be it, --call it whatever you want, but when commercial products don't come even close to meeting their advertised claims, the maker can always expect to be questioned about it... like it or not.

[Dell Winders]

Re: Fox Talk Detectors/Gold Detectors-The Jig is up!

Thanks Randy, I'll add the link you provided to the Treasure America, Product Review forum. I'll be adding details about my own experience with Fox Detectors if I can ever get my scanner to cooperate.

Joe Fox, provides a tangible address at 225 Moonstone Street, Manhattan Beach, Ca. 90266. This same address is listed with the Better Business Bureau as his place of business. The best I can determine, there are two parties named Fox listed at that address, both Female.

Joe Fox, phoned me on March 16th at 1:30 AM eastern time, to inform me that CNN had just aired Fox Detectors in Denver, Co. Dell


TREASURE AMERICA

[Larry Stier]

Re: Carl - Your VR-800 Philosophic Analysis

Mark,

Possibly you could attach your booster to your favorite MD and find all the world's treasures in a week yourself; thus, beating all the rest of us to the punch. Now that's the only scarry thought around here Mark.

Larry

[Brad]

Penetration Capabilities of Magnetometers

G'Day all,

Just a quick question - I've read in several places that the penetration power of magnetometers is very small (that is, they can only detect small ammounts of metal close to the surface). My question, does this "depth" include water? For example, if a mag can detect a one pound mass at a depth of 1m underground, would it detect the same one pound mass if it was on the surface of the ocean, say 10m below?

Thanks for your help,


Brad

[Willy Bayot]

Re: Penetration Capabilities of Magnetometers




Magnetometers can not easily be compared to metal detectors. We do not speak about 'penetration depth' as for the detectors. Magnetometers are passive instrument unlike the metal detectors which are actively magnetizing the ground and its contained targets.
Magnetometers just detect the changes (gradients) of earth magnetic field produced by buried or underwater ferro-magnetic objects or structures.
There is no difference of detection capabilities between ground or water except if the ground is itself highly magnetic (e.g. magnetite).
The detection sensitivity of a magnetometer depends on its resolution expressed in nT (or Gamma). See this picture.

Willy

[Brad]

Re: Penetration Capabilities of Magnetometers

Thanks Willy - so the detection depends entirely on the distance from the magnetometer, not the medium that it goes through? That's what I was after, thanks

One more quick one - I understand the theory behind a PPM, but the other day I was reading about the Overhauser effect, which some companies claim can make their magnetometers 100 times more sensitive (ie down to 0.01nT). The document mentioned using an ionised substance instead of water in the sensor - what would be the best substance to use?

Thanks very much for your help,


Brad

PS What's the relation between nT and Gamma?

[Willy Bayot]

Re: Penetration Capabilities of Magnetometers

Where did you read that?
The overhauser effect gives a much better signal with much less polarization energy and smaller sensors. However, the claim that they give a sensitivity down to 0.01nT is highly exagerated. To get to that level of sensitivity, you need to go to the cesium vapor technology (which is out of reach from hobbyists).
Most of the commercial systems use kerosene or benzene as proton-rich fluids instead of water. They give a better signal with less polarization duration but their relaxation time is also shorter.
The fluid contained in the sensor of Overhauser systems is mixed with a very small quantity (one gram or so) of a radical-free substance. There are a few of them which can be used but they are expensive and dangerous to manipulate.
Moreover, these systems require a RF generator at around 60MHz to trigger the Overhauser effect.
1 nT is exactly the same as 1 Gamma = 1 Tesla x 10-9
Earth magnetic field average is around 50,000 nT.
If you want to know more about PPM, go to this link: http://perso.infonie.be/j.g.delannoy/BAT/PPMGuidelines.htm

Willy

[Brad]

Re: Penetration Capabilities of Magnetometers

Thanks Willy - I'm not sure of the exact link, but it was a commercial model mentioning the Overhauser Effect and a sensitivity of 0.01nT.
If they're out of reach of hobbyists to build, could you still buy a commercial sensor then make your own amp, etc to go with it?

[Willy Bayot]

Re: Penetration Capabilities of Magnetometers

Sure but I doubt that you could buy a sensor alone from a commercial mag company.
In my previous post, I spoke about the cesium vapor systems which are too complex to build by amateurs.
Overhauser mags are not so much out of reach from hobbyists even if they should probably trigger a lot of experimentations. I even plan this to be my next challenging project after I have made my gradiometer work.

Willy

[Brad]

Re: Penetration Capabilities of Magnetometers

Ahh, excellent, thanks very much for the info Willy

Brad