Does analysis weaken with depth?

[Daugela]

So I'm doing my due diligence before I buy my V3i. I came across a person who stated from his experience, the V3i plotter analysis suffered on targets deeper than 4 inches. Surface to 4" - works great VERY accurate. Anything deeper than that accuracy begins to diminish.

His experience with this could be that he didn't master the machine as mush as others have, or possibly there's some truth to it. Once you hit 4 inches, the plotter can give a false reading but the tones say otherwise - causing you to guess and dig.

Thoughts on this?

james

 

[jwebs]

http://www.findmall.com/read.php?66,1713130

There are a few other posts on polar plot, but I think that this one is most relevant to your question.

 

[Daugela]

Yeah, that's just what I was looking for. Thanks

Out of curiosity, is the polar plot the three lines with the camel hump? What's the three lines that all intersect each other?

 

[Rob (IL)]

The above link about covers it. Every detector made loses accuracy on ID with depth. As you saw in the link you had reports of 5" to 9" depending on location. There are areas where all VLF detectors don't ID correctly at all.


Did you ever see the insurance commercial, where the woman says, "It has to be true if its on the Internet". The guy asks, "Where did you hear that"? Her answer is, "On the Internet". It's a large expenditure.

 

[jwebs]

Yeah, that's just what I was looking for. Thanks

Out of curiosity, is the polar plot the three lines with the camel hump? What's the three lines that all intersect each other?

Polar plot is the screen with the vector graph (the X-Y axis) that has the lines that intersect, either being squiggly/looping or straight, depending on your target and depth of target.

The sizing analysis screen is the one with the 3 camel humps. check out pg. 18 of the user's manual here fpr a decent description of this analysis mode:
http://media.whiteselectronics.com/manuals/V3%20Manuals/Spectra%20V3i%20Instruction%20Manual.pdf

I've found sizing to be a good indicator of whether to dig if im suspecting a pulltab--if the 7.5 and 22.5 kHz humps are overlapping or almost touching, it's been a pulltab every single time. There may be other targets that mimic this, i'm sure, but I haven't seen anything yet that does(don't take this as absolute truth, of course--there are exceptions there, I'm sure--i just haven't found them yet)