Density or makeup of the medium

[synthnut]

What role does "Density" play when detecting ....We all know that if there are more minerals in the ground to give us feedback, and that we can't go as deep in mineralized ground , so what role does the density of the sand or the density of the soil play in our detecting abilities ? .....If we had the same mineral content in both hard packed soil or in grainly soft sand, which medum would we see deeper in ? ..... is it only the lack of minerals that allow us to see deeper ? .. .....Jim

 

[Critterhunter]

If you take two types of soil both equal in mineralization (or better yet lacking any at all for this demonstration), there are a few other factors about the soil that will determine depth. The easy one is any kinds of rocks in the soil. Even if they aren't mineralized the structural make up of rocks (not hot rocks even, mind you) I feel makes the magnetic field of the coil start to lose integrity. Most any site I've ever hunted that contained a lot of stones that I wouldn't even say were hot rocks can cause less depth. I'm not even talking about hot rocks or stones that cause falsing in any way. Just about every soil type I've ever hunted that had a good bit of rocks evenly spread within it produces less depth or lousy target IDs. I believe it's disruptive to the coil's magnetic field in some way.

More to your point, though...If you took two soils lacking any rocks or minerals and compared them for depth- One being a tightly packed fine type of soil texture, while the other is far less compact (or should we say having far larger grain structure), then my money is on the tightly packed/fine soil versus one that is less compacted or has less fine particles in it. Why? Because then it all boils down to the coil's field ability to conduct through the soil, and also because in finer medium a coin's halo will be stronger. It will transmit or "conduct" through the finer particles better. Another obstacle (but not for the same reason) would be any trapped air particles in the less fine soil matrix. Minelabs do not like air in the ground load, that's why the don't do as well in air tests...Or should I say, do much better in the ground then in the air. Air testing of my GT is respectable so long as you are away from RF noise, but it's better in the ground from my experience. A more packed matrix with finer particles IMO gives the best depth to the magnetic field as well as the ability of a coin to produce the strongest halo effect.

Moisture content is also a big issue. Take any one of the above soils lacking moisture and they won't give as deep of signals or as good of ones. That's partly due to how halos conduct and other factors IMO.

Good question. Got me thinking.

 

[synthnut]

Crtitter ,
Thanks for your answer ..... Your reply has me thinking too !!..... Since air is not well liked , I'm wondering a few things .....I can read much deeper in the sand at the beaches that I hunt ....There must be quite a bit of air , but a LOT less mneral content and trash in the sand than what is in our local parks ...... So even though there is more air , and the sand is loose , there are far less minerals and trash to deal with so I can go deeper there .......It's raining all over the east coast so I'm thinking ....After a good rain , that will take the air out of the sand an compact the sand more .....Water as a good conductor should then be part of the equation .....So I'm thinking that hunting a beach that has few minerals , after a good rain like this , and maybe the best time that I could ever hunt that beach .....What are your thoughts ? ......Thanks, Jim

PS...I'm also wondering why you are getting better depths on land than on the beach where you hunt ......???????....Is it a mineral issue ?

 

[Critterhunter]

I suspect the make up of the minerals in my land sites is different in some ways than my sand sites. For that reason even if it isn't less in total mineral content perhaps it's the types of minerals on land versus sand. I know that one of the oldest sayings in metal detectors is that certain soil types prefer certain frequencies to penetrate it better. Maybe it's for a similar reason- types of minerals the coil is soaking in? Either way, just glad we own Minelabs so we have several frequencies to cover what various grounds prefer, as well as what various targets of different conductivity properties favor. Best of both worlds.

I'd say that's sound logic- hitting the beach when the sand is compressed from the rain and also contains moisture. Makes sense to me, but here's the one catch...Some soils and sands give less depth when they are wet. It's rare but it does happen. Certain things that "conduct" in the soil due to the moisture can make the soil hotter. I have read this, though the reverse (more depth when wet) is usually true. Depends on the soil or sand, but most will of course do better when wet. Moisture equals conductivity of the magnetic field, as well as better coin halos being generated.

Yea, we are getting rained on here bad too. I've got the GT in the truck and was hoping for a break. It'll be dark in a few hours, so I doubt I'll get out. I am hoping to hit one of my deep coin spots with this good moisture now because we've been bone dry for weeks. That should tell me just how deep the 12x10 will go, as wet is going to be best conditions for depth/target quality. My two deepest coins on the GT (or any machine) were when the ground was real wet. Had it been dry I doubt I would have reached down that 11" or so, at least in the type of soil I was hunting (minerals).

 

[synthnut]

I'd sure be interested to know what Minerals or rocks in the area will get hotter from water ........I never heard of that before ....Ya learn something new every day !!......Thanks for the info ....Jim