Air Test Question ????

[holey dollar]

Guys/Girls
Hope all is going OK for you all,
I was on a forum the other day, i wont mention which forum i was on.
Anyway someone stated that there MD does not get any distance on an air test.
Was on a UK Website they reckon how can you get say 5 inch depth air test and 12 inch depth in the field ???,
a couple of guys stated its impossible. I have a Vaq no problem at all Air test or in the field for good depth.
Would like to know your thoughts,

Holey Dollar/ Dave

 

[Southwind]

5" air test and 12" ground? Not likely. However, under the right conditions you can get a little bit better depth in the ground than you might get with an air test.

 

[nad]

I don't think it is possible to get better depth in ground than air.First of all, the signal (in air) only has air as the limiting medium.Once you add soil,even Florida sand, you have added density, which will detract from the distance. Then add in iron and whatever, and there will be a further loss.The halo effect gave no increase in detectability when tested on a Fisher back in the 70's.I dissolved the coin, made one heck of a halo, and wound up with no signal..May retry with my Silver using a meter to monitor sound intensity (if that would work).... So, the real answer to why the coins did so poorly in air vs soil is super simple...The air test was done with a centimeter measure, the coins in the ground were measured in inches.Two different people doing the testing??. There is a Dutch metal detecting site that compares metal detectors to show the "best ".Last series dated 30 November 2008..The results are so crappy for the Vaquero, that our local waste treatment plant would have trouble keeping up..I think they should hire Dave and me to ground balance their Vaquero, and do some field tests like Southern France, S Italy etc.while in Europe ....There is no way this side of the River Styx a V would give such poor results. Unless?? Anyway, cordially NAD

 

[nad]

Yupper, Yupper, Yupper....5 inches in air times 2.54 (cm/ inch) equals 12.7 inches in da soil..Still a hair flaky. so I'll have oatmeal this morning..Cordially NAD

 

[Jeff Beecham]

Hey Guys,
I tend to agree with you, that what you get in an air test is "about" the max depth
of a detector in the ground in near perfect conditions... But I've owned 3 Fisher CZ's that
blow that theory away.... They don't air test that great, but are real deep in the ground....

I have had a few older Tesoros in the past that might air test around 7 or 8" on a coin but actually find
one a little deeper in the ground from a halo effect built up from being in the ground many, many years....

My wants are... Good depth, great discrimination, easy pinpointing. That's why I prefer Tesoro's over most others...


Happy Hunting,, Jeff

 

[pennysaver]

Why can you pick up a large metal object like a barrel or something at two feet when you can not air test more than 8 inches.?? I think there is more
to the topic I don't understand. The signal clearly goes much deeper than the air test but can the detector or receiver part of the metal detector
pick it up. Food for thought/

 

[Mike Hillis]

Some detectors are designed to hunt in the ground. They have to actually have to have the ground matrix in the signal mix to work properly. The Minelab Soverign GT is a good example of this. Air tests only to about 5 to 7" with the 10" coil but will easily detect coins a foot deep in the ground. This is something that you need to know about detectors when you're shopping for one. If you are hunting woodchips then you need one that hunts good in the air. If you are hunting deep coins in the ground then you want one that hunts good in the ground.

HH

Mike

 

[Mike Hillis]

I've had machines that would air test a quarter out past a foot but had trouble picking up a 7" quarter in my ground.

HH

Mike