halo effect.

i have read on here and other places about this halo effect that objects tend to give off as the soil around the object takes on the objects properties. my question is this. with a low end VLF detector (or any vlf possably) does the detector read to the first sign of this halo or does it filter out and only use the actual target as its source of target id?

It is my opinion that unless the target is iron the Halo effect is overrated. What I think is that freshly buried objects do not detect as well as long lost items because the dirt is aerated. Just my opinion. But I have never been able to see any detector reaction from dirt that was once around a coin.

Ahh boy....the old "halo effect" debate again, and just when everyone was getting along so nice....

That's why I put "my opinion" in my post twice.

Believe what you want but if their is a halo effect especially on copper coins don't you think its a two headed sword and their is halo effect on junk...Heck a horshoe might give off a signal to mask as big as a volley ball.
Personally once found a 2 cent piece that was actually working( bubbling) and leaving a copper color around it the size of much larger object and hit real hard. What makes me think halo's exist making the target easier to detect deeper we all have got deep coin signals and as we dug they disappeared and even though not getting a signal a couple more inches and there it was thus we broke the halo making it impossible to detect that extra inch or so even though the coin was in the hole...If you haven't well you haven't dug many deep copper coins..

I agree with Dan, halo on iron and copper, at lease I have notice it up here, silver and gold, I don't know, they don't seem to deteriorate in the soil like the iron and copper

well i noticed after hitting a nail with the detector that it was spot on with the depth, but with some copper pennies that are extreamly corroded it reads almost an inch or more shallower then the actual target is. so im corn fused and that dosnt suprize me

Rmembering back a while , I know Tom does not put a lot of stock in the Halo effect , but I would have to agree wtih Dan whereby halo'd targets surely seem bigger than life when first detected ......As soon as the halo is disturbed it becomes a different target altogether .......I have never been one to bother looking at my depth meter ...... I go more by the tone .....Jim

I also agree, there may me some "halo" on ferrous and to a lesser extent copper. That being said non ferrous metal does seem to be detected deeper if it has been in the ground a long time. I have always wondered if disturbing the mineralization in the soil some how had an effect on the detecting depth. I have reburied the recovered object in the same hole at the same depth and been unable to re detect it.

since my crappy detector emits the same mono tone at any depth i really on the depth gauge ( i know its a horrable habitt to get into)

LOL...its a 505 Brian....gotta do what ya gotta do. Now get out there and buy one of the bad*** detectors we have recommended

I forgot to add my two cents about halos....its anecdotal, can't be scientifically proven by me, but I also think, from experience in the field, that metals of certain compositions, long buried, leach something into the soil or alter it, that makes the detector more responsive to them.



Edited 1 time(s). Last edit at 05/21/2012 09:59AM by TerraDigger.

B,
Getting back to your other E Trac topic , here is another example of more choices to make on this machine ......Go to the "Audio Menu" in the manual .....Jim

The longer a metallic item is in the ground........... the more compacted the dirt....... in general...... around that object. This allows a much better 'electrical connect' with the ground. The metallic object is more 'grounded'. If the object leaches into the ground........... the 'electrical connect' with the ground is greater. It is not the oxides that provides a better/larger detection of the object............ rather............... it is the fact the metallic item is well grounded...... allowing better detection.

Too much emphasis is placed upon the 'halo'. More focus needs to be placed on the enhanced 'electrical connect'.

I see your point Tom, but isnt it the leaching affect that creates a better electrical connect? The moisture the more connected to the soil some targets get. In salt water copper targets that have been there awhile can almost create a sand ball.... but ive seen it with silver and other targets as well. This appears to be which came first the chicken or the egg to me. Up North in damp areas there was a lot more of the GREENIES and it was pretty obvious it created a larger target field. Although, this combination often made it difficult to get a normal TID.

Dew

lol terra im woking on it working 12 hour days and weekends. wife said if i want it i gotta put in some O.T. and cant take anything out of ye old bank account. damn women and there logical ways

hey tom, does this mean that it would be ideal to detect right after or during a rain? as far as conductivity goes? im not sure if it would be counter productive but as far as electrical goes water tends to be more conductive then soil.

B,
You are correct !!.....You can go deeper after a good rain !!.....Better connection ......Jim

I second Jim. It depends on how the soil drains but generally it is much better after a rain in my experience. Where I am I like to get out the day after a rain and things just open up. Too much rain and it can be bad, especially for higher frequency machines as they get especially sensitive with the little bits and minerals in the ground.

Albert

Wet conditions make iron masking worse, to a degree that is greater than the benefit accrued by the high conductors. But in an iron free/target sparse site, 'wet' is my friend.

Yes........... 'halo' means "good electrical connect". You will detect the TARGET easier...... but not the halo.

I know I've mentioned this before....... and in great detail............. but worth the mention again.

Wet ground will cause targets to be detected easier/deeper........... BUT............. with some stipulations. If the ground is moderately/heavily mineralized............. the water/moisture will 'activate' the mineralization; subsequently reducing/inhibiting the performance of the detector. If mineralization is low........... moisture will 'activate' the metallic targets that have a large halo (decompose/oxides) the most. If you are in a nail infested site.......... and the ground is wet................ this is not a good thing. The nails will be 'activated' the most....... and will mask the non-ferrous targets more readily.

If the ground is saturated............ and has low minerals.............. the detection range of a rusty nail will be greatly enhanced. A gold coin (with no halo/decomposition status..... does not oxidize)........ will show minimal detection depth gain.... in saturated ground.

NASA-Tom Wrote:
-------------------------------------------------------
> The longer a metallic item is in the
> ground........... the more compacted the
> dirt....... in general...... around that object.
> This allows a much better 'electrical connect'
> with the ground. The metallic object is more
> 'grounded'. If the object leaches into the
> ground........... the 'electrical connect' with
> the ground is greater. It is not the oxides that
> provides a better/larger detection of the
> object............ rather............... it is the
> fact the metallic item is well grounded......
> allowing better detection.
>
> Too much emphasis is placed upon the 'halo'. More
> focus needs to be placed on the enhanced
> 'electrical connect'.


If that is true it seem like the object could be detected deeper in the ground than in the air. There would be no grounding in theair

Bad = Freshly buried or 'turned' soil. Target not electrically 'connected'.
Better = Target in compacted dirt for many years.....in natural setting..... and in good 'contact' with dirt.
Best = Airtest. No dirt minerals. Many variables removed.

Tom you are always spot on but with some units they just don't air test well but go several inches deeper in the ground. Guess nothing is carved in stone.....

My Safari seems to airlest OK but I had always heard that the MInelab FBS machines perform better in soil the air. I wonder if the FBS technology is looking for some mineralization and when it does not find any it kinds of detunes it self for some reason - just a totally wild you know what guess based no facts at all.

Aloha

Bryanna

Little air Bad

No air Better

All air Best
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