Pulse Induction Discrimination 20 Plus Years And No New Breakthroughs

[schoolofhardNox]

16 minutes ago, GB_Amateur said:

Almost.  A magetometer in motion is sensitive to magnetic field gradiants (i.e. changes) and ferromagnetic materials are something that causes this.  Both cobalt and nickel are ferromagetic, along with iron as you note.  Alloys of these two metals (not alloyed with iron) must be in fairly high concentrations which is why our USA nickel coin (25% Ni) isn't picked up by a magnet.  But I'm pretty sure there is at least one Canadian coin which is either pure nickel or very high concentration nickel alloy that is attracted to a magnet.

I think tboykin mentioned that above as well.  I can think of *potential* reasons this could be difficult (sensitivity, directional resolution, weight, speed of motion required) but in principle/theory it seems possible.

So does that mean nickel and cobalt will respond to a magnetometer, as well as iron?  Also, we could just use it as a ferrous check (with the press of a button) and not run it continuous if that makes things easier. I would love to have it as a second option after detecting a target with the PI or even any IB machine.

[GB_Amateur]

24 minutes ago, phrunt said:

magnetometers... would be flawed in some of the ground here where there is crazy amounts of black sand. 

I think the point Steve made about ground mineralization relates to what you are talking about.  It's not the magnitude of the mineralziation but rather its non-uniformity.  But ground tracking was derveloped just for this reason -- to handle non-uniformities in ground mineralization.  I've read about locations where, without tracking, the detectorists had to re-balance every few meters (and maybe even less).  I seem to recall Kevin Hoagland went so far to say that in some places he would re-auto-ground-balance at the end of every swing!

10 minutes ago, schoolofhardNox said:

So does that mean nickel and cobalt will respond to a magnetometer, as well as iron?

Absolutely, as long as they are in a form to remain ferromagnetic.  In pure form they are.  I don't know if they maintain the ferromagnetism when bound in compounds (oxides, sulfides, etc.) like iron sometimes does, e.g. magnetite.  And I mentioned that if alloyed with non-ferromagnetic metals where their concentrations take a back seat to those other metals, they typically lose their ferromagnetism.

[Steve Herschbach]

It’s simple. I have used a magnetometer along with a Minelab PI and the PI can hit the nail twice as deep as the magnetometer. No better than lugging a VLF around. So the problem remains the same - no help on the junk where you need help the most, the deepest junk.

[MSC]

I'm working on it. Does anyone here have two JJ6LGCC7 vacuum tubes and a 12KV transformer?

 

Dam Klunker, just gave that stuff to good will, wish I had known. 

[Chet]

I have had good results with two discrimination detectors. The Equinox 800 is used most of the time. But is not any good on deep targets. But it is very useful for pinpointing and/or discrimination once a big hole is started.

When detecting in the California Hydraulic pits with the GPZ-7000 the Magnetic Locator has been a very dependable discriminator for shallow square nails and DEEP cans and LARGE iron junk. It also does well on some magnetic rocks, the kind that a magnet can grip. Not any good on small trash and wire. 

In my opinion three operator selectable modes; Pulse Induction; VLF; and Magnetic Locator technology could be integrated within a single detector. This is feasible with electronic solid state switching to change coil configurations for each mode. The configuration and the sharing of the coil windings and balancing is the most challenging part to accomplish.  
 

[GB_Amateur]

17 minutes ago, Chet said:

I have had good results with two discrimination detectors. The Equinox 800 is used most of the time. But is not any good on deep targets. But it is very useful for pinpointing and/or discrimination once a big hole is started.

When detecting in the California Hydraulic pits with the GPZ-7000 the Magnetic Locator has been a very dependable discriminator for shallow square nails and DEEP cans and LARGE iron junk. It also does well on some magnetic rocks, the kind that a magnet can grip. Not any good on small trash and wire. 

In my opinion three operator selectable modes; Pulse Induction; VLF; and Magnetic Locator technology could be integrated within a single detector. This is feasible with electronic solid state switching to change coil configurations for each mode. The configuration and the sharing of the coil windings and balancing is the most challenging part to accomplish.  
 

Looks like it costs about as much as an Equinox 800, too.

[phrunt]

This guy shows one being used, pretty cool technology.

 

[schoolofhardNox]

2 hours ago, Steve Herschbach said:

It’s simple. I have used a magnetometer along with a Minelab PI and the PI can hit the nail twice as deep as the magnetometer. No better than lugging a VLF around. So the problem remains the same - no help on the junk where you need help the most, the deepest junk.

That's different than I imagined it to be. They use them to find deep buried pipes, so I imagined (even scaled down) they would still beat a PI for smaller targets.  they must lose their punch rather quickly for smaller targets.

[VicR]

Used my Schonstedt in Gusap, Ramu Valley , Papua New Guinea on world war 2 USA / Australian air fields. Had to get a back hoe digger in on one target - proved to be a dump of parts from US trucks and not the  jeep rumored to be buried around that area. Just proved how deep the Schonstedt could go on large ferris targets. The guy with the white t shirt is holding the Schonstedt.

 

[GB_Amateur]

My skeptic detector is ringing up louder than this guy's magetometer.  What's a 'CCR'?  On max sens, the farther he moves the tip from the CCR, the stronger the signal gets.  IMO he's actually picking up other stuff (maybe some iron is his pockets, etc.)  Obviously this device works at some level, but this video has the usual confirmation bias of the user.  Ugh.