Watched the vids for this on YouTube. This machine does not seem to "discriminate" that well, as at one point it did not read the Guys gold ring properly ...it registered as iron. also supposed to have 2 tones.. yet in one video I heard 3
. This seems to be another BS discriminating detector with a 'muti point sampling filter'.
Unfortunately a PI will always fail as a discriminator
due to the properties of iron. If you have a mixed ground with both ferrous and non ferrous targets/mineralisation it will always read the ferrous targets over the non ferrous due to the longer pulse flyback signal (emf decay curve, caused by the stored inductance in the target and the rate of release of this energy). gold = sub 10us, Iron = anything, including and above this depending on its size & shape.
E.g. If you have iron next to gold in the same sweep, the overlap of the decay curve of the iron will mask that of the gold. That is why this form of metal detector is poor on heavily mineraised ground and good for beaches and uniformly mineralised ground where there is a clear difference between ground and your target..
To help with filtering out ferrous in the search for gold items on 'clean' ground with a PI machine you would need to have a fast coil able to handle reading the sub 10us decay curve, a fast enough chipset to compare several sample points to ensure that the decay curve lasts less than 15 - 45us (adjustable, the faster the better) and has a smooth and uniform decay curve of the right shape. Then, when only all the parameters are true it should then return a signal. But beware, by doing this you could sacrifice sensitivity/depth and there is still the chance that it will detect small iron and other non ferrous items, so you might as well take the machine for what it is and just dig everything.
If you want true discrimination go for a VLF machine, it might not search quite as deep on small objects, but it will give you a better idea of your target. But with any machine there are positives and negatives to take into account.
I just wish people would not just 'Research' by reading a few books and watching a few videos made by people who don't fully understand what they are talking about. Research is about discovering and understanding what is happening. For example, a true understanding of what happens when different minerals or a combination of minerals are introduced into an EMF field and what feedback is given in each scenario, as compared to a control environment. - this is where people are doing air tests, and seeing what happens when different minerals are passed across the coil
and not just stopping at passing a coin across the coil then reacting with "oh it goes beep therefore it must work and I'll be able to find my fortune in gold... it does not work that way!!
. The question that should be asked is 'why does it go beep and what parameters are necessary for it to do this and are there different results for each type of mineral.
Now go home and do your homework!
(I might repost some of this on a separate thread re PI detectors and discrimination - what do you think - Mods? thanks LD)
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