How Metal Detectors Work

[mn90403]

Some of us are challenged by the 'technology' of metal detecting and don't have a clear understanding of what happens when we swing a coil.  I'm in that category.  I'm a 'user' and respond to the detector without thorough understanding of what is happening.

I just read this description of how metal detectors work and it will probably change what I think about when I am now swinging a coil.

Is this an accurate, basic description of how we hear a detected object?

How Metal Detectors Work | HowStuffWorks 

[Geotech]

Yes, it covers the basics reasonably well.

[TampaBayBrad]

My first detector as a kid was a BFO unit. That article brought back that memory. ?

[Steve Herschbach]

Not half bad, though I still prefer the original…..

https://bodhi3.files.wordpress.com/2013/05/how-metal-detectors-work.pdf

More here….

 

[mn90403]

From Steve's article:

Is it necessary to know how a metal detector works in order to use it effectively? Absolutely not. Will knowing how it works help someone to use it more effectively in the future? Quite possibly yes, but only with persistence and practice. The best metal detector available is still only as good as the person using it.

Who among us thinks technical when swinging?  Do you actually think about the signal exciting the target and you are right on the edge of detectability with that iffy signal?

[Mike Furness]

MN90403 (Mitchel?)But then again even a blind squirrel finds a nut now and again!?

[mn90403]

Yes, even a blind squirrel can find a patch!

It might depend upon how much of a 'turn on and go' detector you have like a Monster.

[Steve Herschbach]

 

3 hours ago, mn90403 said:

Who among us thinks technical when swinging?  Do you actually think about the signal exciting the target and you are right on the edge of detectability with that iffy signal?

No, I listen for the sound characteristics, loud, soft, sharp, mellow, smooth, erratic, etc that all paint a picture about what kind of target I might have. I’m not thinking about what’s going on under the hood. Same thing when I drive - I’m not thinking about what the pistons are doing and how they are doing it.

[Chase Goldman]

4 hours ago, mn90403 said:

From Steve's article:

Is it necessary to know how a metal detector works in order to use it effectively? Absolutely not. Will knowing how it works help someone to use it more effectively in the future? Quite possibly yes, but only with persistence and practice. The best metal detector available is still only as good as the person using it.

Who among us thinks technical when swinging?  Do you actually think about the signal exciting the target and you are right on the edge of detectability with that iffy signal?

I don't think about the nuts and bolts while swinging.  Like Steve, I'm listening to the audio because there is so much target information contained in the the target audio nuances.  Much more than can be conveyed by a set of numbers or a 2D display.  All of those features and inputs combined paint the mental picture of the probable target.

But some knowledge of how a metal detector works and how the various settings interact from a technical standpoint take a lot of the guesswork out of setting up the detector optimally for the site specific conditions you are encountering that day (EMI, ground conditions, target objectives, junk target composition and density (i.e., primarily ferrous or non-ferrous, machine gun iron, canslaw nightmare, etc.)).  Especially if you have to improvise your settings on the fly because you've encountered something you haven't seen before.  Having a rudimentary understanding helps you know the difference, for example, between increasing or decreasing transmit power and sensitivity and when each tweak should be used, the effects of operating frequency on target acquisition and detection depth, the pros and cons of using disc, notch, recovery speed, iron filters, multi tones vs. pitch etc.

So while it isn't absolutely necessary to understand the detector principles in depth, having some knowledge of the principles can give you an edge in certain difficult situations.

[Joe Beechnut OBN]

On 12/14/2023 at 11:03 AM, mn90403 said:

Some of us are challenged by the 'technology' of metal detecting and don't have a clear understanding of what happens when we swing a coil.  I'm in that category.  I'm a 'user' and respond to the detector without thorough understanding of what is happening.

I just read this description of how metal detectors work and it will probably change what I think about when I am now swinging a coil.

Is this an accurate, basic description of how we hear a detected object?

How Metal Detectors Work | HowStuffWorks 

Years ago there was some great reading and debates over on the Findmall PI forum, Wire Chief, Mr Bill, Eric, Reg, Carl and many others. I just checked there are still a few left but seems many were lost in time when they changed the name of the sub forum, than upgraded to the new look. I really enjoyed watching and reading all, And, Honestly I feel some did help me understand what was going on Around the coil. Maybe the biggest jump was BB Sailors post on the PP switch on his sovereign. As simple as it was, it turned out to be something that affected many and me. God Rest their Souls for sharing.