Why are survey grade so much more expensive than the basic metal detectors you can find for looking for dropped rings etc.
Somebody else will probably give you better answers. But here are a few:
Surveyor models are rugged.
Surveyor models send out a stronger signal. Penetrate deeper.
Treasure hunter models are more fragile.
Treasure hunter models are more versatile.... can find aluminum, silver Gold.
They mostly do their thing up to 12" deep, not much more. I am sure that there are some that go deeper, but they cost more.
Surveyor models can go up to 6' deep, and find a pipe. I have dug them out at 4' with no problem.
I wish somebody would go and test a $1000 treasure hunter, against a schonestedt. And tell us about it!
Nate
well, its like anything else..a very small market size yields a higher price.
Survey grade detectors are not metal detectors, they are magnetic field locators. They do not pick up metal, try one on an aluminum can, coins out of your pocket, if you have some gold or silver laying about try them with the survey graded detector. The cheap metal detectors are just that metal detectors.
Right on the side of my GA52 the decal says Magnetic Locator. Of course if they were made by the millions the price would probably be a lot less.
Jerry M. Davis
Right. And even the best treasure-hunter metal detector is not going to be anywhere near as effective as a magnetic locator at finding a vertical iron rod.
The treasure-hunter responds approximately to the electrical conductivity of the metal times the surface area presented to it. Iron is less conductive than coin metals or aluminum, and a rod presents a very small surface on top. The length of iron below that surface is pretty much irrelevant.
On the other hand, the length of the iron rod is important in intercepting a lot more of the earth's magnetic field, causing a variation over a larger distance. That's why they bother to manufacture magnetic locators.
Bill93,
I should have just asked you directly.
It was a question I have been asked a few times, and just didn't have an answer to.
All great answers. I recently discovered all this when I lent a friend my magnetic "locator" to find his lost necklace. At least he found his necklace - just not using my locator. I was about to return the damn thing when someone explained what you all have just explained.
On another note, are there any "professional" surveyors who use Stainless Steel rods? I ask because I couldn't find the bound I was looking for with that "magnetic locator" but amazingly found it with my cheapo compass (in a granite boulder laden parcel). I know Stainless is slightly magnetic but not enough to trigger my CST/Berger locator. I did, however find several buried tin cans, a guy wire and a telephone wire - all close to the pin but not the pin. So I ask again, why would a professional surveyor use a stainless steel rod? I mean rebar is cheaper and so is iron pipe, right?
> So I ask again, why would a professional surveyor use a stainless steel rod? I mean rebar is cheaper and so is iron pipe, right?
Some soils are too corrosive for plain steel or even galvanized steel. In those cases, stainless may be the best the thing to use, especially if aluminum is unsuitable. If you're using stainless it's probably for a good reason, because it costs an arm and a leg.
Note that some stainless alloys are magnetic, and some aren't.