Best DIY PI kit?

[alexdavey]

There are lots of PI Kits out there, it's hard to find out how they differ. I'm trying to get the best detection depth that I can get for small to medium sized ferrous objects. Any recommendations? I'm not too bothered by LCD displays etc, and it would be great if it was easily available in the UK.

Also, is it worth buying a coil instead of making one?

[Qiaozhi]

There are lots of PI Kits out there, it's hard to find out how they differ. I'm trying to get the best detection depth that I can get for small to medium sized ferrous objects. Any recommendations? I'm not too bothered by LCD displays etc, and it would be great if it was easily available in the UK.

Also, is it worth buying a coil instead of making one?

The MiniPulse Plus has the best documentation, and is capable of sub-10us sampling. It's also the easiest project to construct and get running.
Other alternatives are Surf-PI and Baracuda. If you're proficient in electronics, and have an oscilloscope, then you might want to look at Hammerhead. The HH probably has the most depth.

Out of interest ... why are you are searching for small to medium sized ferrous objects? What type of targets are you looking for?

[alexdavey]

Haha, I thought someone might ask that. Thanks for the recommendation. I am specifically searching for landmines for humanitarian de-mining research. I have tested some commercial metal detectors designed specifically for landmines, but I want to see how they compare to the much cheaper DIY alternative. I suspect that the commercial detectors have better automatic ground balance, and perhaps slightly more depth, but are otherwise comparable. What do you think?

[Qiaozhi]

Haha, I thought someone might ask that. Thanks for the recommendation. I am specifically searching for landmines for humanitarian de-mining research. I have tested some commercial metal detectors designed specifically for landmines, but I want to see how they compare to the much cheaper DIY alternative. I suspect that the commercial detectors have better automatic ground balance, and perhaps slightly more depth, but are otherwise comparable. What do you think?

UXO detectors are designed to search for objects with minimal metallic content. In this case you will need a detector that can provide early sampling, like the MiniPulse Plus. However, none of the aforementioned DIY projects have a ground balance feature, and this might present difficulties searching in heavily mineralised areas. In general though, PI detectors ignore the ground because eddy currents generated in the ground matrix tend to die away before sampling takes place. A lot depends on what the ground conditions are like.