full disc with pi?

[andy]

will the day ever come when pi detectors will have full discrimination, or immunity to small iron? and what response does coke {+ hot rocks} have on a pi

[Ranger]

Re: full disc with pi?

I sure hope it's soon but don't hold your breath. I think that holding it above the ground will help to a point but you lose depth so what is the advantage. I've not found another way other than the height method. There is a system called 'ferrous hound' made in Australia but it costs about $800USD at least which is not exactly a drop in the ocean. I got the impression it was a metal detector in itself as an attachment. I too dream of the day when I can get a PI with a coil to go down 8 meters. The bargain I thought I had had did this but had to be shelved because it would yap at even ferrous clay. Better to be practical than greedy I thought. Eric the original PI inventor had some coils ready to sell me and all.

Unfortunately I haven't worked out how to eliminate the sensitivity with PI. I'd say you would ruin the original circuit if you went playing with it. Good luck. Let me know when you crack it. There's still hope (lol).

Ranger

[John Strange]

Re: full disc with pi?

Hi,
Have you seen this on Eric Fosters PI site.
PI response to Coke and hot rocks is more positive than VLF.

http://www.findmall.com/metal/school1/config.pl?read=6192

Regards John S.

[Eric Foster]

Re: full disc with pi?

Hi John,

PI's do not respond to coke, as it is not conductive enough. Sometimes furnace slag is mistaken for coke and this can give a signal. As to hot rocks, it depends on the mineral makeup. Hotrocks containing magnetite give little or no signal on a PI, but react strongly on a VLF. Rocks with maghemite give signals on both VLF and PI.

Eric.