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Steve Herschbach

Fisher Impulse AQ Discrimination Explanation

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1 hour ago, dewcon4414 said:

Skate.... now I wonder out of that 90% you are getting... how much will other machines hit?   BUT ... reading the weight just mentioned it’s going to grab better than an Xcal I believe.... smallest gold chain last year was .3 grams with the Xcal.

Good question. When I use my equinox I dig everything because on 4 occasions that I can remember I dug 4 targets that started off sounding and reading as iron ended up 3 gold rings and one platinum. With my MDT I've yet to strike gold but I have yet to dig anything that sounded or identified as iron that wasn't. 100% accuracy so far but even that might be skewed as now I pass by any target that doesn't come in on the positive side with the MDT because I have about 200 pieces of junk that read as junk that I have dug in an effort to learn the machine. It makes me wonder how the AQ will do on a beach I detected yesterday that was loaded with hundreds and hundreds of lobster/crab trap shrapnel. Every two steps was another piece. Would the AQ drive me batty at a place like this?

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Luis,

it appears your corroding coin above is a direct relative of the nasty corroding Zinc cents we have here in the US.  As these zinc cents corrode away, they read lower and lower on the conductivity scale, dropping well into the mid-conductor range of the aluminum square tab and pull-tab (man's gold ring).

It will be interesting to know if the Impulse AQ audio characteristics of a corroding zinc cent (or 5, 2 or 1 cent Euro) will be tell tale enough to skip digging them.  ? ? ? ?

 

Rich - 

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UK has its lot as well 1p,2p new 5p new 10p.......rusting in peace in the deep layers of sands.....

 

RR

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Do we know where Platinum falls......it’s usually marked 950 but registers quite low on typical VLF machines. I know I have skipped over Platinum with my Excalibur.....my TDIBH eats this stuff for breakfast in AM mode.

Platinum is popular down here with the Japanese which means there is plenty lost in Hawaii I’m guessing ?

 Tony 

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Platinum can be marked many different ways.  PLAT, 800, 850, 900, 950 and 1000.  My best year, I got 18 platinum rings and a platinum cross loaded with diamonds with the platinum chain.  But we are not finding platinum rings like we used too here in Honolulu, Hawaii. So many people now wearing titanium and tungsten carbide rings.  I miss the old days where you could dig up 10 rings and 9 would be either gold or platinum.  Now you are lucky if 1 ring out of 10 rings is gold or platinum.

 

 

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Yep......same down here as well 😤

 

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I would like to come back to the brown euros. I didn't really understand .. these coins rot very quickly on the beach. And even in good condition they are not in the conductivity range of pulltab, with a nox they have a ferrous sound.

Alexander, you say we can reject them but losing a 25 gr ring 18k. ok anyway these rings are quite rare. 

 can we reject them and keep the rings from 2gr to 15 gr ?

If I am in an area full of these coins, in reject mode, Impulse can see through to detect a ring underneath them? What is the exact rejection setting to reject them? 6,7,8 .. ??

thank you

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Hello Alexandre,

You have been using the Impulse for a good amount of time now and are certainly having success with it and have the most amount of testing time. 

I watched / listened to the latest Video on the Impulse from December hoping to hear more of the audio responses. As you are recovering the corroding 5, 2 and 1 cent Euro coins, are you able to distinguish a difference in the audio report when compared to a clean gold ring ?  The US cent that is copper plated zinc corrodes away quickly and falls down into the mid-conductor range. 

I am wondering if there is any audio help for us as we carefully listen to a signal. 

Second question. I live not far from a high salinity lake bed.  (Great Salt Lake) How would you anticipate performance of the Impulse AQ in an area with a very high wet salt content ?

 

UtahRich 

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7 hours ago, vive equinox said:

I would like to come back to the brown euros. I didn't really understand .. these coins rot very quickly on the beach. And even in good condition they are not in the conductivity range of pulltab, with a nox they have a ferrous sound.

Alexander, you say we can reject them but losing a 25 gr ring 18k. ok anyway these rings are quite rare. 

 can we reject them and keep the rings from 2gr to 15 gr ?

If I am in an area full of these coins, in reject mode, Impulse can see through to detect a ring underneath them? What is the exact rejection setting to reject them? 6,7,8 .. ??

thank you

Yes for 9k 10k 14k 18k, no problem

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59 minutes ago, UtahRich said:

Hello Alexandre,

You have been using the Impulse for a good amount of time now and are certainly having success with it and have the most amount of testing time. 

I watched / listened to the latest Video on the Impulse from December hoping to hear more of the audio responses. As you are recovering the corroding 5, 2 and 1 cent Euro coins, are you able to distinguish a difference in the audio report when compared to a clean gold ring ?  The US cent that is copper plated zinc corrodes away quickly and falls down into the mid-conductor range. 

I am wondering if there is any audio help for us as we carefully listen to a signal. 

Second question. I live not far from a high salinity lake bed.  (Great Salt Lake) How would you anticipate performance of the Impulse AQ in an area with a very high wet salt content ?

 

UtahRich 

I will be making videos in the coming weeks.

For your Great Salt Lake, unfortunately I don't have the answer.
I think there must be so many different cases...

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      References
      Da Costa, A.C.S, Bigham, JM, Rhoton, FE, and SJ Traina. 1999. Quantification and Characterization of Maghemite in Soils Derived from Volcanic Rocks in Southern Brazil. Clays and Clay Minerals, v. 47, no. 4, p. 466-73.
      Hunt, CP, Moskowitz, BM, and SK Banerjee. 1995. Magnetic Properties of Rocks and Minerals. In Rock Physics & Phase Relations: A Handbook of Physical Constants, Volume 3.
      Koch, C.B, Borggaard, OK, and A. Gafur. 2005. Formation of iron oxides in soils developed under natural fires and slash-and-burn based agriculture in a monsoonal climate (Chittagong Hill Tracts, Bangladesh). Hyperfine Interact 166, 579–584.
      Rivers, JM, Nyquist, JE, Terry, D.O., and W. E. Doll. 2004. Investigation into the Origin of Magnetic Soils on the Oak Ridge Reservation, Tennessee. Soil Science Society of America Journal, Vol. 68 No. 5 p. 1772-1779.
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