Any thoughts on why two silver earrings readout so low on the CTX

I beach hunt a lot, and find a fair amount of gold and silver jewelry. In the past two years I've been using the CTX almost exclusively and have been "fooled" with three finds to date that had a readout in the lower gold range (lower 12/5-15) , had a nice gold finish yet were marked .925..... all three were plated and silver inside. Two recently found are almost identical in size, approx. 1/2" hoops and both had the stem closed on the earring. I'm assuming that they are marked 925 due to having more silver than gold in the makeup yet I would have thought I would have had a readout more in the silver range then in the gold range. White gold typically will read out higher in the gold range and 10k typically will also readout higher too.... So, do machines decipher the return readings, from the target surface metal instead of the total makeup of the metal?

Cliff

Remember, VDI is averaged. So take a nickel and a dime hold them together and see what the VDI reading is. The lower conductor will drag the number lower. Also, smaller silver tends to read lower had a 1/2" flat silver rabbit earring read like a nickel.

Bey

They may be hollow/thin and react much like a broken ring with that gap.

Beyonder-Pa Wrote:
-------------------------------------------------------
> Remember, VDI is averaged. So take a nickel and a
> dime hold them together and see what the VDI
> reading is. The lower conductor will drag the
> number lower. Also, smaller silver tends to read
> lower had a 1/2" flat silver rabbit earring read
> like a nickel.
>
> Bey


Hey thanks Bey, it was just bothering the heck out of me, especially thinking I had gold the whole time out there until I got my loop to see the 925. I'm understanding that the machine electronics analyzes the change of the field due to the inductance/resistance of the targets and eddy currents set up on the surface of the metal. Makes a bit more sense now...... :-)

Dew, both of these earrings were closed so they weren't reacting as a broken ring does, the other notable one was a yellow gold plated silver channel set ring....readings said gold, looks said gold, markings on all three.....925!

Cliff

Gold....... silver... heck pull tab you are digging it unless it say iron. Oddly Cliff a Silver half will show up on your screen lower as well. Just keep digging those targets and counting your loot you ole pirater.

Dew

>So, do machines decipher the return readings, from the target surface metal instead of the total makeup of the metal?

Yes.

Cliff, it's the fact that they were gold plated. The eddy currents that your detector induces are on the outside of the object it detects.
Plating fools electronic gold testers just as well as metal detectors.


mike



Edited 1 time(s). Last edit at 04/11/2015 11:27PM by Mike in CO.

Remember white gold reads real low ....Heck my wifes white gold wedding ring with a nice diamond reads plus 7-8 on an XLT on a scale of minus 95 to plus 95....with a nickel reading plus 18-21....

dewcon4414 Wrote:
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> Oddly Cliff a Silver half will show up on your screen lower as well.
>
> Dew

Dew,
I've heard the rumor that big silver will read low on some machines, but not on Cliff's CTX. The CTX will lock in a silver half anywhere between 12-44 and 12-47...silver dime 12-42 to 12-46...depends on the ground and the mode.
Very consistently.
(nickels, for comparison, about 12-13...)

Only time I've seen silver read slightly low was co-located next to low conductors.

I do like your advise about digging anything but iron. I've been picking up a lot of rings lately in terribly hammered areas. (Been picking up a lot of tabs and foil, as well.)

HH,
mike

Mike in CO Wrote:
-------------------------------------------------------
> >So, do machines decipher the return readings,
> from the target surface metal instead of the total
> makeup of the metal?
>
> Yes.
>
> Cliff, it's the fact that they were gold plated.
> The eddy currents that your detector induces are
> on the outside of the object it detects.
> Plating fools electronic gold testers just as well
> as metal detectors.
>
>
> mike

After the original post, I did a bunch of reading and came to that conclusion, thanks Mike...

Cliff

Mike..... grab an Explorer and put a SILVER half in the ground.... it will show a lower Ferr/Cond number than a SILVER quarter. I believe Andy Sabash even mentioned this in his book. Cliff is my CTX guy, ive not used one..... so i get to pick on him lol. A lot changes in the ground when the machine averages the number, size and density of the target.

Dew

Dew, not sure on the Silver half but a clad half hits higher than a quarter on the screen and most silver hits there too.... unless it is gold plated... :-)

Cliff

Just had to find out since I may never see these in Florida on the beach....so I tested a Walking Liberty half, a Morgan Dollar and a Walking Liberty Round 999 fine here are the results..... IF this works, first time trying to add photos.

Walking Liberty Half

[i1148.photobucket.com]

Morgan Dollar

[i1148.photobucket.com]

Walking Liberty Round 999 fine

[i1148.photobucket.com]

Cliff