Designing and marketing new metal detectors.

[deemon]

Considering what have you said earlier; i think 12V gell cell accus would be perfect choice.
Those are lasting long and there is very easy to way replace them on the field and charge them later.
Especially if IB detector is used with current drain in range 40-80mA with such gell cell accu.

For low power consumption we can use recuperative PI design , why not ? And its low sensitivity to ground ( because of constant current in the coil during measuring interval ) is quite a useful property too .

[ivconic]

Solid enclosures. Good first choice.

How do the prices and quality compare with products from China?

We must at all times keep the eye on the cost, because it is maybe THE most important factor.

Tinkerer

Example:

Lower rod= $ 9.95
Middle rod= $11.99
Upper rod= $23.99
..................
$45.97


I like those:

[Tinkerer]

For low power consumption we can use recuperative PI design , why not ? And its low sensitivity to ground ( because of constant current in the coil during measuring interval ) is quite a useful property too .

Hi deemon,

would you be so kind and expand/explain on that: because of constant current in the coil during measuring interval ) is quite a useful property too .

Tinkerer

[ivconic]

So is $45.97 for complete "shaft"!
And it is 3-part shaft, my favorite!
It is cheap indeed.
And it is even a sale price!
Would be significantly less if 100 pcs are about to be bought.
Some discount always can be negotitated with provider!

[deemon]

Hi deemon,

would you be so kind and expand/explain on that: because of constant current in the coil during measuring interval ) is quite a useful property too .

Tinkerer

Yes , the initial idea was to reverse the current in the coil instead of stopping it , so the energy stored in the coil isn't wasted in the load resistor , but can be returned to the battery . But if we begin to return the energy just after the flyback , it will be difficult to select the weak response signal coming from the metal objects , so I decided to hold the reversed current after the flyback pulse ( shorting the coil ) , wait about 100 uS ( measuring interval ) , and after this I can return the energy without any problem . But during this interval the current flows through the coil , and special circuit makes it constant all this time , in contrary with conventional PI design with its exponential current decay .

And if the current is constant , magnetic field in the coil and near it is constant too , so we can't change the ground magnetization during our measuring interval , and we can eliminate this cause of the soil influence . Some time ago I told about this design here - http://www.geotech1.com/forums/showthread.php?t=19273 . So I can answer all the questions in that topic , of course .

[UncleMatt]

New to the site, but intrigued by this thread, and wanted to offer another feature idea. Perhaps it would be nice to add a smartphone dock on the side of the unit housing to offer the end user the ability to add a bunch of additional features that don't necessarily need to be included in the base unit hardware.

For example, if I could dock my smartphone on the side and be able to connect with the unit's system and record with it the GPS track I have covered, as well as GPS locations for all finds and signals, as well as general mapping, that would be very useful. This would amount to no more than a unit integrated micro-usb port and a simple retaining mechanism on the unit's exterior. To maximise effect, you could orient the dock so the phone display could be utilized while prospecting. With various apps you could offer a range of prospecting and MD related utilities. And it would also increase marketing appeal if people knew they had the option of integrating their smartphone to the MD...

[ivconic]

New to the site, but intrigued by this thread, and wanted to offer another feature idea. Perhaps it would be nice to add a smartphone dock on the side of the unit housing to offer the end user the ability to add a bunch of additional features that don't necessarily need to be included in the base unit hardware.

For example, if I could dock my smartphone on the side and be able to connect with the unit's system and record with it the GPS track I have covered, as well as GPS locations for all finds and signals, as well as general mapping, that would be very useful. This would amount to no more than a unit integrated micro-usb port and a simple retaining mechanism on the unit's exterior. To maximise effect, you could orient the dock so the phone display could be utilized while prospecting. With various apps you could offer a range of prospecting and MD related utilities. And it would also increase marketing appeal if people knew they had the option of integrating their smartphone to the MD...

Yes that's nice approach.
And sooner or later all the technology will tend to integrations. Already do.
Android platforms are having very bright future.
So designing metal detector compatible to android platform is very smart move!

[UncleMatt]

Yes that's nice approach.
And sooner or later all the technology will tend to integrations. Already do.
Android platforms are having very bright future.
So designing metal detector compatible to android platform is very smart move!

Other benefits leap to mind as well. If you integrate the smartphone display with signal outputs from the MD, deaf people could have better access to metal detecting, since they would no longer be dependent on audible signals from the unit. So the app would show you on the phone display when you get a good signal, and also perhaps use the built in vibrator in the phone to give a tactile signal as well! This could be expanded on in many ways obviously.

What we need is someone well versed in smartphone hardware and software for integration purposes. Anyone here have that expertise? If not, I am fairly certain I can find someone who is who is willing to join the group and lend a hand.

[kt315]

Excellent discussion thats why i joined geotk!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


RR

ABSOLIUTELY nothing of new. you can go and make sure of. Carl had wrote all aspects, but somebody is thinking there is something fresh and he is leader in mindstorm.
http://www.geotech1.com/forums/showthread.php?t=13554

Tinkerer is great guy, but SUNNY activity in his latitude is wildest now. the sun burns the head.

[hdphilip]

hello Matt,

What we need is someone well versed in smart phone hardware and software for integration purposes. Anyone here have that expertise? If not, I am fairly certain I can find someone who is who is willing to join the group and lend a hand.

I thought about using a smart phone, but my thinking is to have a dedicated processor for the metal detector, but if it helps, I'm using a display from a semi-smart phone in my
also I have 4 LED's which will indicated different levels of detection, which would aid the hearing impaired.
my project:

http://www.geotech1.com/forums/showp...5&postcount=52

or the display:

here's a video of it working

http://youtu.be/7wdZT2Id9kM


Philip

PS:

the use of LED's is patent pending
the use of graphics LCD for target response is patent pending
the use of copper in any form in the making of a metal detector is patent pending
the use of any material listed on the periodic table and any physics pertaining to electron flow is also patent pending

just kidding..........

[ivconic]

Actually there is a lot of information available.

Maybe we could convince Carl to open a repository where we could upload the information that we can find on Google, so that it is easily available for all interested parts?

Tinkerer

Low metallic content mines are generally plastic explosives with few metal parts inside.
Those are most difficult mines for a metal detector to find, especially in soil.
And fact is that most of modern mines are such kind.
Therefore we will have indeed hard task here!
Small metallic parts that are in mine are most probably made from titanium alloys.
My dear friend WM6 recently sent me one small screw made from such alloy via mail.
Objective was to test Deus on such item.
I was more than surprised that Deus even detect it!
90% of other detectors i know were not able to detect it at all or only when "wiped" of coil surface.
So i already am aware of how hard task it is; to make such "mine detector" that will be really useful.
Yet it is worth of try. And i have good will to learn more on this subject.

[ivconic]

"...An object’s detectability is a function of the induced magnetic field’s strength and an object’s conductive properties, size, shape, and position. For example, copper, aluminum, and ordinary steel are good conductors and relatively easy to detect. Stainless steel is harder to detect than an identical piece of ordinary steel because it offers more resistance to the induced magnetic field and thus produces a weaker or smaller secondary magnetic field.
Portable metal detectors operate on either the continuous wave or pulse method of transmitting and receiving. Continuous wave detectors induce and monitor magnetic fields continuously to sense any disruptions caused by a conductive object’s secondary field; pulse detectors transmit and receive in alternating cycles in search of secondary magnetic fields..."

[ivconic]

"...According to defense intelligence information...
Low-metallic mines have been represented in Army tests of portable and other detection systems since 1983 and were included in the performance specifications used for the 1991 procurement of the xxxx. Army officials informed us that a separate technology effort was underway before 1991 to address the low-metallic and nonmetallic threat. The Army plans to complete this effort by fiscal year 2001..."

[ivconic]

"...Fuzes used in some of these mines contain between 0.4 and 1.5 grams of aluminum. Depending on the type, these mines may contain from one to three fuzes, any one of which is capable of detonating the mine. Examples include the TMA-1 and TMA-5, which contain one fuze; the TMA-2, which contains two fuzes; and the TMA-3 and TMA-4, which contain three fuzes.
The most difficult to detect are the PMA-1, which contains less than 0.4 grams of aluminum in its fuze, laid horizontally in the mine, and the PMA-2, which has a vertical fuze (a more difficult position for detection) containing 0.5 grams of aluminum. For detection purposes, the metallic content of multiple fuzes is not additive; according to Army officials, the fuzes are positioned far enough apart in the mine as to generally limit detection to one fuze at a time...."

[ivconic]

"...The specification described the following targets to be detected in three different types of soils—sand, loam, and magnetite (an iron-based soil):

• a small steel pin, 4.5 millimeters long, to simulate the M-14 mine (detection
of this pin was desired but not required in magnetite);
• a hollow aluminum tube, 44.5 millimeters long and 6.4 millimeters in
diameter;
• a steel PMN-6 striker pin, 57 millimeters long, one-third of which was
4.8 millimeters in diameter and the remainder 9.5 millimeters in diameter;
and
• a simulated M-16 mine.

According to the 2.46 gram standard, the M-14 pin and the aluminum tube represented low-metallic targets. The M-16 is a metal-clad mine. The PMN-6 striker pin falls somewhere between the M-16 and the low-metallic 3This requirement falls between the nearly 100-percent detection required for mine clearance operations, like those in Bosnia, and the 80-percent detection required for rapidly cutting through minefields under combat conditions.
Page 5 GAO/NSIAD-96-198 Mine Detection B-272391 targets. The designation PMN-6 refers to a British-made training mine that is a replica of the Soviet PMN mine. Like the Soviet mine, the PMN-6 training mine has a nonmetallic case and contains several metal omponents in addition to the striker pin, which collectively amount to over 17 grams of metal. According to the National Ground Intelligence Center, the striker pin itself would not qualify as a low-metallic target because it contains several times the amount of metal as the M-19...."