# Advanced metal detecting

**URL:** <https://boards.straightdope.com/t/advanced-metal-detecting/711421>\
**Category:** Factual Questions\
**Created:** [January 31, 2015, 12:44pm UTC](https://boards.straightdope.com/t/advanced-metal-detecting/711421 "2015-01-31T12:44:57Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Consensus](https://avatars.discourse-cdn.com/v4/letter/c/3be4f8/32.png) [@Consensus](https://boards.straightdope.com/u/Consensus)\
**Post date:** [January 31, 2015, 12:44pm UTC](https://boards.straightdope.com/t/advanced-metal-detecting/711421/1 "2015-01-31T12:44:57Z")

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I recently got a metal detector (I’m an absolute noob in the field) and got some ideas to possibly improve methods of detecting.

I was wondering why all detectors operate in a flat field. Is it not possible to add a dimension for depth ranging or more accurate field detection?

And secondly how hard would it be to process the data into some sort of graphical representation on, or with the aid of, a smartdevice?

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**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\
**Post date:** [January 31, 2015, 4:23pm UTC](https://boards.straightdope.com/t/advanced-metal-detecting/711421/2 "2015-01-31T16:23:15Z")

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I guess I don’t know what you mean by “flat field.”

[Top-of-the-line metal detectors](http://www.whiteselectronics.com/spectra-v3i-w-hp) are pretty sophisticated. It’s a very competitive field, and if there was a way to make them better/more accurate while keeping the price reasonable, rest assured they will do it.

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**Author:** ![Consensus](https://avatars.discourse-cdn.com/v4/letter/c/3be4f8/32.png) [@Consensus](https://boards.straightdope.com/u/Consensus)\
**Post date:** [January 31, 2015, 5:49pm UTC](https://boards.straightdope.com/t/advanced-metal-detecting/711421/3 "2015-01-31T17:49:11Z")

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From what I understand most detectors work with two D shaped coils forming one circle in the horizontal plane. As you move these two coils over an conducting object both fields get disturbed with a small difference, making detection possible. What if you added two more in the vertical plane and achieve higher accuracy through triangulation.

Obviously I am no expert on magnetic fields, but I always thought they were three dimensional. But I’m perfectly willing to accept that adding another set of coils in a different plane will yield no additional information.

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**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\
**Post date:** [January 31, 2015, 6:14pm UTC](https://boards.straightdope.com/t/advanced-metal-detecting/711421/4 "2015-01-31T18:14:45Z")

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> [@Consensus](#):
>
> Obviously I am no expert on magnetic fields

I’m not either. All I can say is the magnetic fields around the coils _do_ exist in three dimensions, and they _do_ penetrate the earth. They are designed and oriented to achieve optimal performance in terms of depth and sensitivity while also being small and lightweight.

At any rate, your question is valid, and perhaps someone else here could answer it. But on a higher level, it should be stated that metal detectors have been around for many many decades, and the technology is fairly mature. I am confident that if something can be done to improve the accuracy of a standard metal detector while maintaining a reasonable price point, they will do it. Also keep in mind that ergonomics is a _huge_ issue with metal detectors; they _must_ be light and comfortable to use.