Smart phone metal detector ??

[dowser]

If they can develop an app, that can read a resonating frequency, than yes, why not.
I already learned how to change the frequency of my cell phone to any frequency I want.
And multiple compatible Frequencies can be ran at the same time.
It doesn't need to be put on the ground, I just carry it in my pocket.
But, they haven't figured an electronic way to indicate a frequency in an app yet, like Dowsing rods indicate..

Here is someone using their cell phone.
Not just me!

 

[Carl-NC]

Smart phone metal detector... So...why hasn't this happened yet ?? And how easy could this be ?

It has been done, about 6 yrs ago:



From what I've heard, it did not perform very well. Such a design is limited to using Bluetooth to transfer digital data and it's possible this is a severe limitation. XP avoids this by using a proprietary method that avoids the overhead of Bluetooth. As things improve, probably a decent cell phone metal detector will come about.

less than -30dBm

this is the amount of firepower that a detector can produce and still be legal.

Merrill makes some OK videos but in this case he has no idea what he's talking about. Whole video is full of wrong information.

 

[AstralDruid]

You could be right Carl... as i say , I am just going by his video... Seems to be difficult enough to get info on this 'power' radiation safety limit .... if indeed there is one.. I am of the persuasion that it is indeed kept to a level so that the coils don't emit dangerous levels.. but not yet able to find any real proof !!
Anyone ?

AD

 

[dowser]

less than -30dBm

this is the amount of firepower that a detector can produce and still be legal.
All detectors are governed by the same regulations.
So,, the machines are kept below this level of radiation emission (for user safety apparently) , thus limiting their ability... Bigger coils, faster separation, sensitivity, etc etc .... are all just done by the processor, so these are the only gimmicks that companies can play around with,, perhaps producing some minor improvements in user friendliness but no real world power advantages...
Them's the rules,, i don't make them.. and neither do XP or Minelab

AD

I met a guy in Arkansas, and we went into the Ozarks searching for KGC treasure.
He was using a custom made metal detector, running an illegal frequency.
It was supposedly better at something.
I only know he wouldn't run it for long, in fear of getting detected, using an illegal frequency, not licensed to use.
The illegal frequencies I've read about are high Frequencies in MHz, Ghz and above.
Low Frequencies are better for depth I read, not sure what he was using.

 

[Blak bart]

It has been done, about 6 yrs ago:



From what I've heard, it did not perform very well. Such a design is limited to using Bluetooth to transfer digital data and it's possible this is a severe limitation. XP avoids this by using a proprietary method that avoids the overhead of Bluetooth. As things improve, probably a decent cell phone metal detector will come about.


Merrill makes some OK videos but in this case he has no idea what he's talking about. Whole video is full of wrong information.

Well....there ya have it....already someone on it !! I want my wand and coil to be built by mine lab like in my photo, and I want to hard wire it, and have the ability to go Bluetooth. I would use my old galaxy 10 wich is still good . Clearly it can be done....I expect there are a bunch of legal and other copyright, and patent problems along with business deals that would have to happen to make it reality for the masses.

To be clear im not talking about more power, just the same performance I get from minelab, but for the price of a coil and stick, and the compatibility and ease of using a smartphone as the remote, controller, or control pod or whatever you call it.

Also the other features offered by a phone are a bonus, that i think better minds than mine would figure out how to utilize and interface with for a multitude of reasons that I haven't even dreamed of yet. Examples were the camera, satellite imagery, lidar, GPS, measuring distance, etc. etc.

I have no dog in this hunt.....just a thought i had when I set a phone on top of my equinox600. Seems pretty logical....combine all the features of your smartphone with a detector !! Its a software application problem of communication....all the hardware already exists!! It looks like the future to me...thats all !!

 

[Sandog]

AI Overview



For hobbyist metal detectors, the primary regulation governing the device's technology, particularly its radio frequency (RF) emissions, is the Federal Communications Commission (FCC)
. Unlike industrial or security metal detectors, which have more extensive and specialized oversight, hobbyist units are regulated as low-power, unlicensed transmitters under FCC Part 15.
Regulation of radio frequency
The FCC regulates the radio frequency (RF) emissions from hobbyist metal detectors to prevent interference with authorized radio communications.

• FCC Part 15: This section of FCC rules applies to "unintentional radiators" and "low-power, non-licensed transmitters," which includes hobbyist metal detectors.
• Emission limits: Manufacturers must ensure their devices meet FCC standards for transmission strength, spurious emissions, and RF exposure. A device that causes interference must be corrected by its operator.
• Operating frequency: Regulations governing RF emissions apply to frequencies above 9 kHz. Below 9 kHz, there are generally no RF restrictions in the US. This is relevant to metal detectors because the RF field produced by the coil is contained and does not radiate like a radio transmitter.

Regulation of technology standards
While the FCC deals with radio transmissions, other entities may influence the standards of metal detectors for specialized purposes. This is not for hobbyist devices but for more professional equipment:

• National Institute of Standards and Technology (NIST): NIST has worked to develop documentary performance standards for specialized metal detectors, such as handheld and walk-through devices used for security and law enforcement purposes.
• American Society for Testing and Materials (ASTM): The standards developed by NIST have been formalized through organizations like ASTM to create international testing and performance standards for security metal detectors.

 

[99thpercentile]

This was done ages ago in the geophysics world for metal detection of unexploded ordnance (UXO). All of our instruments utilize at a minimum what we call digital geophysical mapping (DGM), which is the digital sensor output combined with global navigation surveying system (GNSS) or other high accuracy positioning systems. Many of the instruments can show a colorized map of the gridded data on the screen in real time.

The Geophex GEM-3 handheld metal detector with the locator bar can map the data in real time as you swing the sensor back and forth. It can then match targets to a library. So if you have a quarter or a dime it will identify it. It also has a library of UXO targets. The first version of the software was probably written around 2007 for Windows Mobile and the current version is for Android.

Hand-held Gem-3 – geophex.com

geophex.com

Geomar Software write their real time mapping software for the Geonics EM61-MK2 that will generate a map of the data in real time. I use RTmap38MK2 with my Geonics EM38-MK2 and RTmap61MK2 with my Geonics EM61-MK2.

Geonics EM61-MK2A Time Domain Metal Detector

Geonics EM61-MK2 Metal Detector, leading tool for buried metal detection, UXO and other military high resolution investigations.

www.geonics.com

Geophysical Software for EM and Magnetic Surveys | Geomar Software

Geophysical software for electromagnetic and magnetic surveys using Geonics and Bartington instruments. RTmap, TrackMaker, and Multi systems support real-time mapping, GPS/RTK positioning, data acquisition, and processing.

www.geomar.com

The instruments mentioned above are pretty basic, the more advanced instruments are know as advanced geophysical classification (AGC) for the UXO industry. Most of these instruments are capable of getting a 100% on the receiver operating characteristics (ROC) curve that means detecting 100% of the UXO under the ground on a site potentially up to about 3 m (~10 ft), 100% discrimination which means sort all targets into UXO or non-UXO, and 100% on classification which means for each item identified as UXO determining the depth, inclination, declination and model of UXO.

GapEOD UltraTEM-III or UltraTEM-iV
Geometrics MetalMapper
White River Technologies OPTEMA or APEX
TEMSENSE AGC Sensor

I'm testing my universal metal detector data logger prototype right now that can digitize the headphone output of any metal detector and merge it with GNSS data for real time mapping. I was testing it in my driveway last week with my partner on the project and we collected data from a number of different metal detectors. It doesn't do the real time mapping yet, just the logging, but it will soon.

 

[Blak bart]

AI Overview



For hobbyist metal detectors, the primary regulation governing the device's technology, particularly its radio frequency (RF) emissions, is the Federal Communications Commission (FCC)
. Unlike industrial or security metal detectors, which have more extensive and specialized oversight, hobbyist units are regulated as low-power, unlicensed transmitters under FCC Part 15.
Regulation of radio frequency
The FCC regulates the radio frequency (RF) emissions from hobbyist metal detectors to prevent interference with authorized radio communications.

• FCC Part 15: This section of FCC rules applies to "unintentional radiators" and "low-power, non-licensed transmitters," which includes hobbyist metal detectors.
• Emission limits: Manufacturers must ensure their devices meet FCC standards for transmission strength, spurious emissions, and RF exposure. A device that causes interference must be corrected by its operator.
• Operating frequency: Regulations governing RF emissions apply to frequencies above 9 kHz. Below 9 kHz, there are generally no RF restrictions in the US. This is relevant to metal detectors because the RF field produced by the coil is contained and does not radiate like a radio transmitter.

Regulation of technology standards
While the FCC deals with radio transmissions, other entities may influence the standards of metal detectors for specialized purposes. This is not for hobbyist devices but for more professional equipment:

• National Institute of Standards and Technology (NIST): NIST has worked to develop documentary performance standards for specialized metal detectors, such as handheld and walk-through devices used for security and law enforcement purposes.
• American Society for Testing and Materials (ASTM): The standards developed by NIST have been formalized through organizations like ASTM to create international testing and performance standards for security metal detectors.

🤔🤔🤔 hmmmmmm.....I wonder how much power a phone is allowed to radiate.....maybe?? Its more than the detector, and could be directed to energize the coil somehow??

 

[Blak bart]

This was done ages ago in the geophysics world for metal detection of unexploded ordnance (UXO). All of our instruments utilize at a minimum what we call digital geophysical mapping (DGM), which is the digital sensor output combined with global navigation surveying system (GNSS) or other high accuracy positioning systems. Many of the instruments can show a colorized map of the gridded data on the screen in real time.

The Geophex GEM-3 handheld metal detector with the locator bar can map the data in real time as you swing the sensor back and forth. It can then match targets to a library. So if you have a quarter or a dime it will identify it. It also has a library of UXO targets. The first version of the software was probably written around 2007 for Windows Mobile and the current version is for Android.

Hand-held Gem-3 – geophex.com

geophex.com

Geomar Software write their real time mapping software for the Geonics EM61-MK2 that will generate a map of the data in real time. I use RTmap38MK2 with my Geonics EM38-MK2 and RTmap61MK2 with my Geonics EM61-MK2.

Geonics EM61-MK2A Time Domain Metal Detector

Geonics EM61-MK2 Metal Detector, leading tool for buried metal detection, UXO and other military high resolution investigations.

www.geonics.com

Geophysical Software for EM and Magnetic Surveys | Geomar Software

Geophysical software for electromagnetic and magnetic surveys using Geonics and Bartington instruments. RTmap, TrackMaker, and Multi systems support real-time mapping, GPS/RTK positioning, data acquisition, and processing.

www.geomar.com

The instruments mentioned above are pretty basic, the more advanced instruments are know as advanced geophysical classification (AGC) for the UXO industry. Most of these instruments are capable of getting a 100% on the receiver operating characteristics (ROC) curve that means detecting 100% of the UXO under the ground on a site potentially up to about 3 m (~10 ft), 100% discrimination which means sort all targets into UXO or non-UXO, and 100% on classification which means for each item identified as UXO determining the depth, inclination, declination and model of UXO.

GapEOD UltraTEM-III or UltraTEM-iV
Geometrics MetalMapper
White River Technologies OPTEMA or APEX
TEMSENSE AGC Sensor

I'm testing my universal metal detector data logger prototype right now that can digitize the headphone output of any metal detector and merge it with GNSS data for real time mapping. I was testing it in my driveway last week with my partner on the project and we collected data from a number of different metal detectors. It doesn't do the real time mapping yet, just the logging, but it will soon.

Dude !! That is something....this must cost an arm and leg...no pun intended 🤣

 

[DizzyDigger]

🤔🤔🤔 hmmmmmm.....I wonder how much power a phone is allowed to radiate.....maybe?? Its more than the detector, and could be directed to energize the coil somehow??

Radiate power at what frequency? The low freq. of a metal detector requires more power
to radiate than your cell phone does in it's operating range.

 

[Blak bart]

Radiate power at what frequency? The low freq. of a metal detector requires more power
to radiate than your cell phone does in it's operating range.

I dont know these things...how much power would it take....batt looks about same power wise ? What would it take a battery pack ?

 

[Carl-NC]

Seems to be difficult enough to get info on this 'power' radiation safety limit .... if indeed there is one

This is covered in the 3rd edition of Inside the Metal Detector.

but for the price of a coil and stick

Yes, but now the coil has to have the basic metal detector circuitry inside it (TX & RX), along with a battery. Basically a Deus coil. A Deus coil cost $200-300, and a Deus2 coil is $350 & up. The alternative is to use a cheaper cabled coil and then add a circuit+battery box, much like a regular metal detector, at which point the cell phone is mostly replacing the display and keypad. And how well can you see your cell phone screen in bright daylight?

This was done ages ago in the geophysics world for metal detection of unexploded ordnance (UXO). All of our instruments utilize at a minimum what we call digital geophysical mapping (DGM), which is the digital sensor output combined with global navigation surveying system (GNSS) or other high accuracy positioning systems. Many of the instruments can show a colorized map of the gridded data on the screen in real time.

I don't think these guys were looking that far ahead, they were just proposing a cell phone to replace the control box. Besides the Air metal detector, do you know of any geophysics devices where the primary UI is a cell phone?

I'm testing my universal metal detector data logger prototype right now that can digitize the headphone output of any metal detector and merge it with GNSS data for real time mapping.

Wouldn't you want to capture the quadrature data? That info is lost by the time it reaches the headphones.

I wonder how much power a phone is allowed to radiate.....maybe?? Its more than the detector, and could be directed to energize the coil somehow??

No, the coil will need a regular TX circuit.

 

[MtnManJack]

Not sure if this has already been posted or not (don't have time to read through the whole thread), but there's this:

https://www.questmetaldetectors.com/questair

 

[Blak bart]

This is covered in the 3rd edition of Inside the Metal Detector.


Yes, but now the coil has to have the basic metal detector circuitry inside it (TX & RX), along with a battery. Basically a Deus coil. A Deus coil cost $200-300, and a Deus2 coil is $350 & up. The alternative is to use a cheaper cabled coil and then add a circuit+battery box, much like a regular metal detector, at which point the cell phone is mostly replacing the display and keypad. And how well can you see your cell phone screen in bright daylight?


I don't think these guys were looking that far ahead, they were just proposing a cell phone to replace the control box. Besides the Air metal detector, do you know of any geophysics devices where the primary UI is a cell phone?


Wouldn't you want to capture the quadrature data? That info is lost by the time it reaches the headphones.


No, the coil will need a regular TX circuit.

This is where I was getting confused....I think....I still only see one battery in a detector feeding the screen and coil...? Right? Except the deus.....and 350 for a deus coil that works with my phone is way cheaper than the full kit....I use my android alot in the bright light while fishing....its not bad....and my sound works good in the sunlight too.

 

[Blak bart]

Not sure if this has already been posted or not (don't have time to read through the whole thread), but there's this:

https://www.questmetaldetectors.com/questair

Yup...thats more along the lines I was thinking....and there it is...here comes the next wave of detecting it looks like....maybe it dies out like the do do bird, or maybe its the next generation of detector!!

 

[99thpercentile]

This is covered in the 3rd edition of Inside the Metal Detector.


Yes, but now the coil has to have the basic metal detector circuitry inside it (TX & RX), along with a battery. Basically a Deus coil. A Deus coil cost $200-300, and a Deus2 coil is $350 & up. The alternative is to use a cheaper cabled coil and then add a circuit+battery box, much like a regular metal detector, at which point the cell phone is mostly replacing the display and keypad. And how well can you see your cell phone screen in bright daylight?


I don't think these guys were looking that far ahead, they were just proposing a cell phone to replace the control box. Besides the Air metal detector, do you know of any geophysics devices where the primary UI is a cell phone?


Wouldn't you want to capture the quadrature data? That info is lost by the time it reaches the headphones.


No, the coil will need a regular TX circuit.

I would absolutely want to collect the quatrature data, unfortunately only a few instruments actually output real data. A few of my military metal detectors output real data over RS-232 and I can lot those along with positioning data. Most of the hobbyist metal detectors only output an audio signal. It is obviously less useful than raw data, but a lot of projects are just bump detection so being able to map the digitized audio outputs is better than no logged data.

I am just trying to make better use of the instruments than someone stopping every time they hear a whee-whee sound and digging holes. I want to map targets across an entire site.

 

[99thpercentile]

Dude !! That is something....this must cost an arm and leg...no pun intended 🤣

What something costs and whether you think it costs an arm and a leg is very subjective.

I tell people that most geophysical instruments start at $20,000 USD, but I have been saying that for years and probably need to adjust it for inflation. I own well over $500,000 worth of geophysical instruments for context.

I'm doing some marine magnetometer surveys in the near future to look for some sunken ships and will be taking around $100,000 worth of equipment with me.

 

[99thpercentile]

Radiate power at what frequency? The low freq. of a metal detector requires more power
to radiate than your cell phone does in it's operating range.

I've done testing on a range of geophysical instruments to determine how much power they radiate. This was for a project to see if it was possible to accidentally trigger the fuse in an unexploded ordnance (UXO) while performing geophysical detection surveys over it. We set up sensors in a very large anechoic chamber at at Navy facility. We mounted each sensor in the center of the chamber and measured the background signal with the equipment turned off, then turned on, and then transmitting. We then made a bunch of test fuses and measured the induced current in the fuses while doing the same test.

We could not trigger any fuses with any of the sensors.

 

[Blak bart]

What something costs and whether you think it costs an arm and a leg is very subjective.

I tell people that most geophysical instruments start at $20,000 USD, but I have been saying that for years and probably need to adjust it for inflation. I own well over $500,000 worth of geophysical instruments for context.

I'm doing some marine magnetometer surveys in the near future to look for some sunken ships and will be taking around $100,000 worth of equipment with me.

I have used magnotometers before for shipwreck work....so i understand there costs and uses well. Amazing with the unexplolded ordinance and how advanced that tech is....that will save lives !!

 

[DizzyDigger]

We set up sensors in a very large anechoic chamber at at Navy facility. We mounted each sensor in the center of the chamber and measured the background signal with the equipment turned off, then turned on, and then transmitting. We then made a bunch of test fuses and measured the induced current in the fuse

99th..quite familiar with anechoic chambers, or RF test chambers in general. Before I retired,
I was the Pac NW sales rep for ETS-Lindgren, one of the worlds largest manufacturers of RF,
microwave and acoustic test chambers. I'm not an engineer, but do know a thing or two about
test chambers, antennas, measurement instrumentation, probes, etc..

If I could afford the lab time, I'd love to get a detector in a proper chamber and see what it's really
putting out in terms of power. Also, it would be a good time to see how susceptible it is
to RF/Microwave interference.