Need help locating or building a super deep PI detector

[cliffscot]

I am trying to detect a large non-ferrous object (bronze) at a depth of 30-35ft through about 20ft of water. Are there any commercial detectors out there that will do this? I could careless about all the small targets. If someone has built something like this I am looking for a design. Eric Foster built a large one for Mel Fisher years back.... Ideas??

[1843]

Hi cliffscot,

Go to the site www.proton-service.de

There are many commerical PI that can go so deep. They are very stable and not sensitive to salt water, etc.

Here is the best one: http://www.proton-service.de/html/antares.html


Good luck

[Max]

I am trying to detect a large non-ferrous object (bronze) at a depth of 30-35ft through about 20ft of water. Are there any commercial detectors out there that will do this? I could careless about all the small targets. If someone has built something like this I am looking for a design. Eric Foster built a large one for Mel Fisher years back.... Ideas??

Hi,
don't know what's your budget... but I think that you can use a magnetometer if object is large... say some square meters surface.

You have to made some research about sensitivity/resolution you need.

The mags are not good for small non-ferrous stuff... but if the thing is really large you can tow by a boat one e.g. cesium kind and get accurate mapping.

If object is great enough the mag will show a magnetic anomaly there.

The advantage of using a mag is also that you can find it for underwater applications ready on the market... where , instead, is more complicated for a large underwater PI thing... with large underwater coil towed etc.

You can make things "easy" using some wire-driven depth control system for the large coil (the kind used e.g. in deep water fishing... with metallic wires that go deep when towed at right boat speed...and you can calculate depth knowing the speed of boat) BUT then you'll risk your coil there... cause always possible will be hooking some underwater structure... wrecks etc
I think that a PI could also detect the object if very (but very) large at that depth from top water... but the probability of miss it are well higher than with the mag in this case even using a very large coil.

Consider that 30-35ft are not distance for common PIs... you need use very special equipment and have no 100% detection in that range of distance.

Kind regards,
Max