scale of where metals fall?

[haxor]

Awaiting my first MD (Ace350)

Is there a chart of where different metals fall? Sure the MDs have iron, gold and silver marked.
But I'm curious as to where brass, alum, lead, copper, bronze, platinum, etc. fall.

(and only for grins how does radioactive materials react to a MD?)


tia
Eddie

 

[OWK]

Generally.....


Silver will be at the top of the scale,

then Copper/brass/bronze

Then zinc/lead

Then aluminum

Then iron.

Gold can be anywhere in the spectrum... If you want to find gold, you'll have to dig everything but iron.

Also, various shapes may change the way a metal is identified.

Many detectors will ring up iron bottle caps as much higher (maybe even as high as silver)

Many detectors will also ring up aluminum can fragments much higher.

I have found that the rounder the target, the more abnormally high it rings up.

My advice to you, is to set your discriminator to reject nails (low iron) and then dig EVERYTHING else.

At least until you learn your machine.

Good luck.

 

[haxor]

Thanks! Gold, I'm not too anxious about, other then lost jewelry at a park. (and understand it prefers a different freq)

I do plan on ~zero descrim & digging most everything at first.

 

[OWK]

I'm sure there are some good Youtube videos on the 350.

They can be very helpful.

 

[Tom_in_CA]

haxor-eddie: owk gives a good answer so far. Just be aware that size plays into the equation too. To illustrate this, take an entire aluminum can and wave it in front of your 350. You'll see it registers up at dime or quarter or whatever, (on the high end of scale), right ? Ok, now take a snippet of the can (or just use the tab) and wave that in front of your 350. You'll notice it reads at nickel or tab or whatever, right ? But wait! what changed?? In each case it was the exact same composition: ALUMINUM. Hence the only thing that changed was the size

Thus some mental sizing (of the size signal in your audio) is also a useful tool in deciding dig versus don't dig.

And as for gold jewelry: It comes in infinate sizes and shapes. Also karot differences (10k, versus 14k versus 18k versus 22k or pure, etc....). So you can throw any notion of identifying gold out the window. If you want to find gold jewelry, go to where it's most likely to be found: Swimming beaches. NOT junky inner city blighted parks

 

[Charlie P. (NY)]

 

[Skippy SH13]

Hey Eddie, I run an ACE350... It's a great machine, and you'll appreciate the DD coil for target identification.

As OWK notes, metals of specific types can fall in ranges you'd not expect. This is due to the amount of metal and shape. For example, aluminum will typically show up in the aluminum range (it'll show foil/gold on your screen), but large cans can ring up as silver. The more metal there is, the more disruptive to the field. As a result, Iron chunks in the ground (like a 4 pound steel plate), can ring as high as silver.

EXPECT to spend a bunch of hours learning your equipment, and don't give up. It was about 100 hours for me, before I felt confident enough to selectively discriminate what I dug. I run in jewelry mode, almost exclusively (it takes everything but iron). You will find that you'll need to dig EVERYTHING for a while, to learn what those signals mean. Just because it's a quarter signal, doesn't mean it's a quarter. For example, bottle caps will show as quarters, until you hit the VERY edge of them with the field, and the notch will go down to iron. As a result, with this knowledge, you can start to predict what is probably a bottle cap (it'll notch to iron), vs. what is actually a quarter.

Dig it all.

Cheers!
Skippy

 

[Charlie P. (NY)]

Here's another one that was from Garrett, I believe.



Note that it doesn't always work. Your detector knows ferric (iron) from non-ferric (all other metals) and it guesses based on assumptions the objects are coin sized and shaped. The detector senses relative conductivity of the soil (when ground balanced) and anything conductive that comes into the coil's field. The "assumptions" are what is programmed into the software parameters. So, when your detector says "Silver Dollar, six inches deep" and you dig an aluminum bottle cap at 4" or an aluminum pie tin at two feet you know it guessed wrong.

Better detectors are just better guessers. ;-)