How does a metal detector 'know' one metal from another?

[Route 66]

I don't understand how a detector can determine one type of metal from another. I've searched this forum but haven't been able find an answer to my question.

Can someone here please tell me how metal detectors can differentiate silver from copper from tin from zinc from aluminum, when it's in the ground?

[Lowjiber]

I'll send you something you may enjoy. On the way via email in about ten minutes.

[suttle]

please send it to me too

[Lowjiber]

Done.


If it doesn't arrive, please advise. :)

[ssserena]

The etrac has a hard to telling the difference between a nail and a quarter.

[Stormrider51]

The etrac has a hard to telling the difference between a nail and a quarter.


I'm sorry, but no it doesn't. The E-Trac gives TWO values, ferrous content and conductive. The ferrous value of a nail and a quarter are different. On my E-Trac a quarter will show a Fe value of 11 or 12 and a conductive value of about 44 to 46. I've never dug a nail that read in that range. As a matter of fact, I've never dug a nail since I came to understand what the Trac is telling me except for when I wanted to confirm my data. The audio tone on iron objects goes low and often broken with the settings I use. Plus, by taking advantage of the narrow 1 X 11 detection zone of the DD coil I can determine that I have a long narrow object down there. Taken together, I can feel confident about leaving something in the ground. I'll confess that I'm an old detectorist who started in the days of non-discrimination detectors and until fairly recently I was of the if it beeps, dig it school of thought, but times have changed.

Storm

[z118]

The etrac has a hard to telling the difference between a nail and a quarter.


Uh... no it does not. You either have a defective machine or you are still very, very early in the learning curve.

[CTDirtFisher]

The etrac has a hard to telling the difference between a nail and a quarter.


Nails and Quarters are not even close on an E-Trac... as you gain more experience and knowledge you will be able to tell the difference...

[ssserena]

Depends on who you ask ct dirtfisher.Nails and quarters are close but the raspiness is more noticable with nails and with quarters its nice and sharp and crisp.Does this makes sense.

[Epi-hunter]

Depends on who you ask ct dirtfisher.Nails and quarters are close but the raspiness is more noticable with nails and with quarters its nice and sharp and crisp.Does this makes sense.

The Fe and Co numbers on a nail are not the same as with a quarter, ssserena. Even with a very deep quarter, the Fe and Co numbers will generally stay in the quarter range repeatedly and from different directions. I think that's what the others are trying to say. You are correct that the tone may differ too. But with experience you should be able to easily tell the difference. The pinpointing will be off with a nail too.

I have owned and used machines where it was genuinely hard to tell nails from good targets (such as the Fisher CZ3D) but the E-Trac isn't one of them.

[ssserena]

I hunted one of the oldest churches in my state and really struggled with tons and tons of nails!I would be glad to take anybody there to see what im talking about!In all seriousness!The quick mask has helped me though its saved me a lot of digging.Angel you are the pro at the etrac and I will take any advice very serious.Thank you!

[Stormrider51]

Enough nails or other metallic trash can overwhelm any detector's ability to separate and ID targets. I have permission to hunt one old homesite where the trash is incredibly thick. I took my E-Trac there and finally gave up after about an hour. I went back with my DFX and gave up again. I'm getting an XP Deus and will go back with it but I'm betting the results will be the same.

Storm