Nasa's Etrac Evaluation & Test Results/Status

In all of my detecting (and testing) whilst in 'conductive' mode..........nails give a false 'coin' tone.....and coins give a 'coin' tone. A solo nail has high ferrous numbers (with subsequent/corresponding cross-hair location).............as to be expected. A coin will give low ferrous numbers (with subsequent/corresponding cross-hair)...........as to be expected.
......Yet..............when a coin is partially masked by a nail........(coin and nail co-located) the corresponding 'ferrous' numbers are high again......and any form of ferrous Disc will 'mask' the coin (and nail combo). I cannot amelioriate........nor can I alter ferromagnetic (in concert with) electromagnetic principles of physics.
If the nails signal-strength is stronger than the coin.............the nail wins.
If the coins signal-strength is stronger than the nail.............the coin wins.

If a coin were buried at a detectable depth/range..........with no other metal object in close proximity...........the unit will ID the coin with great accuracy. If you take a salt shaker or pepper shaker..........and very lightly start to 'sprinkle' very small iron flakes on top of the location of the coin..........as to be expected.............the ID accuracy of the coin would linearly diminish............and the corresponding ferrous number(s) would linearly start to climb........whilst continuing to sweep the target..........whilst more iron flakes are being continuously added to the coin location..............until.............the coin becomes overtaken by the iron flakes (and in short order). Controlled environment......definitive testing; will verify/validate this phenomenon. During this process.........you will also see the conductivity of the coin 'average down'.

Ferrous items have a 'electro' and 'magnetic' signature.
Non-ferrous items only have a 'electro' signature.....in laymans terms... (whilst exposed to a external electromagnetic source).
This is also to say that ferromagnetic items present twice the problem (2X problem) for detectors.

Shambler Wrote:
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> One of the strengths of the Explorer is that the
> bouncing cursor is easier to lean than 20+ numbers
> zooming buy - in my opinion. I've also found
> that too much iron mask on an explorer will kill
> you with deep iffies because the null in certain
> directions on GOOD targets isn't far left corner
> hits, it's on the top to the right of that corner,
> but the nulling tricks you into thinking it's iron
> when in fact it's just registering into your iron
> mask area.

Shambler -- I am not versed enough with the Explorer to completely follow either of the things you mentioned there -- "learning the cursor bounce," and how "too much iron mask can kill you" in that some good targets "null" into the top right of your matrix, and thus is not iron but instead "registering into your iron mask area." I don't understand all this yet.

> I agree completely. After the first several deep
> "iffies" are investigated in an area, you can
> better make a decision on whether to continue
> digging them. I just know that sometimes I'll get
> bored with swinging for a long time and just
> decide to dig an iffy that turns out to be a great
> find - then think, "crap", I have passed up 10 of
> those signals

I hear you! And that makes alot of sense. I will try to dig more of the deep "iffies" with this machine, and see what I find. Thanks for these thoughts; as for your thoughts above, guess I need some more experience!

Steve

Interesting info above, Mr. D. -- I will test in my test garden and see if my results match yours...but makes alot of sense.

Steve