Today, we’re going to take a look at how the metal detecting technology works on a basic level, some uses for metal detectors you may or may not have expected, and some things to consider when purchasing one. Then, we’ll look at the TOP 5 of the best standard metal detectors on the market for various uses, preferences, and budget.

When you think of metal detectors, one of three things come to mind. The first is the armchair treasure hunter, combing the beaches and trails of touristy locales for lost relics both old and new. Another, with a more negative (due to inconvenience) connotation is the application of the technology which makes us all empty our pockets of change and keys before boarding a plane. Finally, for those enthusiasts of action and war movies, there’s their use to find land mines and other traps, often with a tool not dissimilar to what beachcombers use, albeit more advanced.

The truth is, they’re used for a lot more, though average people tend not to see these applications. Metal detectors can be used to find buried power lines and piping, get a survey of metal deposits in a plot of land, and for forensics.

Since the physics behind metal detection is rather dense, we’re really only going to give the science behind this a basic glance.

What’s a Metal Detector and How it Works?

A metal detector is, as the name would indicate, a sensor that detects metallic objects that you may not be able to see. They are useful for finding relatively shallowly-buried metal objects, ore deposits, and metal fragments that have made their way into other less-than-transparent materials.

Not all metals are detectable, and not all detectors can detect all of the same things. But, the basic principle, regardless its implementation, is the same across most of these. Metal detectors create an electromagnetic field or pulse, which is diffracted by many types of metal – especially what’re called ferromagnetic metals. These are metals susceptible to magnetism and conductors of electricity.

Not all metals are ferromagnetic, but most of them are. These metals cause distortion, delay or absorption of the magnetic field, which indicates the presence of metals. The amount of distortion along with timing circuitry, can mathematically deduce to some extent how large the object is and how deep, though these two readings are often approximations.

How Deep will a Metal Detector Go?

This can vary, but most consumer metal detectors have an average range of less than a foot, though industrial metal detectors can actually reach as deep as several feet.

What a Metal Detector Can Detect

As said above, the technology for metal detectors is based around electromagnetism, which means that it will detect metals that conduct electricity and are susceptible to magnetism. Ferrometals, as these are usually called, are more common than metals that are not. Prime examples of metals most detectors won’t easily spot are very pure aluminum, surgical titanium, and a few industrial insulator metals designed specifically to have low radar profiles or prevent signal interference.

In the case of “treasure hunting”, most valuable metal items will show up, due to traces of ferromagnetism present in alloys not made by highly modern processes. The same can go for security and industry – metal detectors are commonly used to sweep industrial complexes for stray metal waste that can injure people or damage vehicles, and most of this debris is impure enough to set off a detector. The same can be said for most weapons.

How a Metal Detector is Made?

The make of metal detectors isn’t very complicated, fundamentally. It utilizes two different polar magnets (which forms the vague concentric rings you see at the end of them), between which a modulated magnetic field is generated. It really is that simple.

What (and Where) are Metal Detectors Used For?

Metal detectors see a large range of uses across a number of fields. Security is an obvious one, to detect weapons and technology that may be prohibited beyond checkpoints. The most obvious and relatable of these is at airports, but in some areas, schools, courthouses and other public places also make use of this technology.

In industry, metal detectors are used to map out metal pipes, wiring and other infrastructure. It’s also used to find debris that could harm people or damage vehicles (such as nails and shrapnel). It’s also used for health concerns, to find metals in food and other goods, which doesn’t belong there.

How Does a Metal Detector Work in the Food Industry?

The food industry generally uses metal detection technology more like what’s used in security, rather than handheld utilities or the wand variety used by hobbyists. This technology is utilized to prevent contamination by industrial waste accidents, and to prevent tampering. Random bits of metal in food could result in poisoning, injury or even death, so the use of metal detection in this industry is very important.

Types of Metal Detectors

There are a number of metal detector types, and while they basically use the same fundamental electromagnetic technology to spot disruption (and in some cases reflection/deflection), the implementations of these can vary.

  • Beat-Frequency Oscillation – This is a more precise application of the concept, where the magnetic field is modulated in a base pulse similar to what AM radios used to use for tuning, and the disruption of the mathematical beat frequency can be calculated to determine the presence of metals.
  • Very Low Frequency – This creates, as the name would indicate, a low frequency field, and really only provides base detection. The advantage to such low frequencies is the higher range and deeper penetration possible.
  • Pulse Induction – This is similar to beat-frequency oscillation but a bit less sophisticated, pulsing the magnetic field, and producing a measurable current through induction, which is diminished by interfering ferrometals.
  • Industrial – Industrial metal detectors are used for security, food service and industrial applications.
  • Gold and Relic Hunting Detectors – These are honestly usually either pulse induction or something even simpler (an unmodulated field that simply diminishes sharply when ferrometals are contacted).

How to Choose a Metal Detector: What to Look for When Buying?

When you’ve decided you need a metal detector, there are a handful of important things to consider. 

  • Purpose – Are you using this for a hobby, security, or industry? A standard pole-based detector is really not practical for security, and only some industrial purposes, where it’s the best for hobbyists. 
  • Frequency – What are you looking for, and what are you trying to detect things through? Different frequencies and modulation practices are better suited for specific types of metals, or to scan through specific materials. 
  • Pinpointing – This isn’t something that all metal detectors can do, but the more sophisticated ones, with more modulated fields, can actually do zooming to pinpoint more precisely where, laterally, a detection is, and how deep it is. 
  • Ground balance control – Control over the field for balancing (to account for different geologies) is also helpful, as this can be very diverse even in a localized area, and can severely affect the ability to detect something. 
  • Other features – Controllable frequency modulation can allow for parameters to look for specific families of metals at specific depths, though these are things only really high-end detectors can enable with any real success. 
  • Handling Pole – You will want a comfortable handling pole that distributes weight, allowing you to do smooth scanning motions while not growing rapidly fatigued. 
  • Budget – Fancier detectors tend to be relatively expensive, and if you’re doing this for a hobby, it’s something of a gamble.

Personal Experience: How I Didn’t Become a Treasure Hunter

For a brief time when I was in college, this was actually a hobby I enjoyed. I managed to actually find some interesting things, too. Now, these were mostly mid-range jewelry, some coins from the turn of the century or newer, that sort of thing. These were worth money, but I never found some treasure worth a fortune doing this.

That’s not to say none of my friends whom shared the hobby didn’t. One of them actually found a pouch of gold and silver coins from the 1800s buried near an abandoned old house. Lucky son of a gun.

Honestly, the only reason I fell out of the hobby was because I am not a big fan of hiking or really nature as a whole, and metal detecting usually takes you on lengthy walks through the local wilderness. When I pursued this hobby, the detectors available for consumer use were not nearly as powerful or precise as even the low-end modern ones, and my goodness, were they heavy.

I can vouch for a solid, comfortable handling pole and well-made detection coils being a blessing, because some magnetic devices can be horribly heavy. Ones with active detection, which requires a power source, are even heavier.

The ones that I used were the simplest concept in the world, a magnetic field (not specifically modulated or otherwise cleverly implemented), which would indicate there was indeed something metallic in the ground below. There was no zoom, there was no automatic ground balancing, there was no pulse modulation to see deeper into the ground.

The thing to take away from this is, do spend some time being sure you’re comfortable with how one of these handles, and if you can, opt for fancier detection methods where available, and appreciate that automatic ground balance where available, because my goodness, was that always a pain in the butt.

Top 5 Metal Detectors

Hereinbelow, we’ll cover the best metal detectors we’ve found online: great for beginners, all-purpose uses, as well as super modern and more advanced versions from trusted brands.

Bounty Hunter TK4 Tracker IV Metal Detector – Excellent All-Purpose Detector

Bounty Hunter TK4 Tracker IV Metal Detector: photo

This is the quintessential hobbyist and mobile industrial detector of the 21st century, mixing computer-controlled internals with traditional knob-and-gauge interface (which is great as a familiarity for veterans of using these). The automation for ground balance and the presence of a powerful discrimination control makes this a very accurate, very easy to use metal detector very ideal for hobbyists both old and new.

Features

  • Pole-Mounted: Yes.
  • Audio Discrimination: 2-tone.
  • Headphone Jack: 1/4”
  • Built-In Speaker: Yes.
  • Waterproof: Yes.
  • Depth: Coin-sized items at 8 inches, larger objects at 2 feet.
  • Ground Balance: Automatic.
  • Display: Gauge.
  • Interface: Switch dials.

Performance

This is very similar to the one I had, albeit a lot more modern, and mine couldn’t reach 2 feet down even on loose soil. That’s legitimately impressive. I myself would prefer, out of a modern detector, a digital display, but this is coming from a computer-inclined person who was never married to gauges and dials for readouts.

I can completely understand how many people would appreciate a simpler traditional readout/control interface like this, and it does admittedly require less power as a result. But, high-capacity power supplies are getting smaller and lighter in weight every day.

Pros Cons
  • Easy to use.
  • Automatic ground balancing.
  • Waterproof.
  • Comfortable handling pole.
  • Good search depth.
  • Two-tone detection range.
  • Analog readout.
  • Obtuse quarter-inch headphone jack – who uses this jack form factor in the 21st century? 
  • A little pricey for a run of the mill detector. 
  • The electrical line on this sort of design can be frail – be careful in bushy areas.

Conclusion 

I am mostly comfortable recommending this to hobbyists, especially beginner or intermediate ones.

Bounty Hunter Tracker IV: Check the current price

NATIONAL GEOGRAPHIC PRO Series Metal Detector – Excellent Portable Treasure Hunting Detector

NATIONAL GEOGRAPHIC PRO Series Metal Detector: photo

This is an example of modern technologies being applied very heavily, yet elegantly, to the traditional metal detector. This one isn’t cheap, but when you look at the features, power and convenience of this unit, you won’t feel like the price is remotely unreasonable.

This detector has modern digital readouts and membrane buttons, rather than clunky old dials and gauges. It’s collapsible and weighs only two pounds, which is actually pretty impressive – mine was so heavy.

Features

  • Pole-Mounted: Yes.
  • Audio Discrimination: 2-tone.
  • Headphone Jack: Standard.
  • Built-In Speaker: Yes.
  • Waterproof: Yes.
  • Depth: Coin-sized items at 12 inches, larger objects at 3 feet.
  • Ground Balance: Automatic.
  • Display: Digital.
  • Interface: Membrane buttons with computer display menus.

Performance 

This one actually amazes me for, if no other reason, the fact it can detect aluminum. This is something most metal detectors can’t do very well, because aluminum isn’t particularly ferromagnetic, which is property metal detection primarily depends on. No metal is completely immune to magnetic wave interference, however, which means that this has one very precise detection coil, to see the minor perturbances aluminum can do.

With detection modes and a compact nature, this is definitely the modern detector I’d have if I still pursued this hobby. Wow, where was this technology when I was into metal detectors?

Pros Cons
  • Easy to use.
  • Automatic ground balancing. 
  • Waterproof. 
  • Comfortable handling pole. 
  • Good search depth. 
  • Two-tone detection range. 
  • Can detect aluminum!
  • Expensive.
  • A bit bulky despite being light. 
  • Can jam.

Conclusion 

This is a solid metal detector, and the ability to detect aluminum is something impressive. I’m actually not sure how they manage this with any efficacy, to be honest. I’d recommend it.

NATIONAL GEOGRAPHIC: Check the current price

Fisher F22 Weatherproof Metal Detector with Submersible Search Coil – Great for Intermediate Users

Weatherproof Metal Detector with Submersible Search Coil: photo

This metal detector offers slightly more advanced controls, along with a more basic but intuitive display, producing an excellent metal detector for intermediate users. Are you ready for something a bit more powerful and advanced than your first detector? This might be worth a look.

Features

  • Pole-Mounted: Yes.
  • Audio Discrimination: 2-tone.
  • Headphone Jack: Standard.
  • Built-In Speaker: Yes.
  • Waterproof: Yes.
  • Depth: 9”, 1.5’ for large objects.
  • Ground Balance: Automatic.
  • Display: Digital.
  • Interface: Clicky-buttons and digital menus.

Performance

This detector is run of the mill in its capabilities, it’s the finesse with the controls, and the overall balancing, alongside price, that make this ideal for intermediate users. It works just fine, and has adjustable sensitivity levels.

It is best for treasure hunters, but then, that’s what most of these detectors tend to be mostly used for.

Pros Cons
  • Easy to use.
  • Automatic ground balancing. 
  • Waterproof. 
  • Comfortable handling pole. 
  • 9 adjustable levels.
  • A bit pricy.
  • Run of the mill features.

Conclusion 

This is the quintessential second detector, and for that, I am happy to recommend it. But, it’s not truly special. Does it need to be, though?

Fisher: Check the current price

Garrett Ace 300 Metal Detector – Great Entry to Modern Detectors

Garrett Ace 300 Metal Detector: photo

If you’re a seasoned user, and aren’t looking to fix what isn’t broken, this is a great way to upgrade to modern displays and improved technology without giving up most of the sensibilities you’re used to. The digital display Is easy to see, it’s very weather-resistant, and all around balanced.

Features

  • Pole-Mounted: Yes.
  • Audio Discrimination: 2-tone.
  • Headphone Jack: Standard.
  • Built-In Speaker: Yes.
  • Waterproof: Yes. 
  • Depth: 8-10”, 2.5’ for large objects.
  • Ground Balance: Automatic.
  • Display: Digital.
  • Interface: Clicky-buttons and digital menus.

Performance

This seems like a modernized version of my old detector, and it thinks like an old detector in how it presents its readouts. Old hands at this hobby, looking to update their technology but not their habits, will find this a good foot in the door, definitely.

Pros Cons
  • Easy to use.
  • Automatic ground balancing. 
  • Waterproof. 
  • Comfortable handling pole.
  • LCD can be a bit hard to see.

Conclusion 

This doesn’t fix what isn’t broken, this is your standard advanced metal detector, but with the improved frequency technology and less ambiguous readouts. If you want to take advantage of advances, without the detector being too much of a leap out of your wheelhouse, I recommend this one.

Garrett: Check the current price

Bounty Hunter Land Ranger Pro Metal Detector – Ultimate Treasure Hunter

Bounty Hunter Land Ranger Pro Metal Detector: photo

If you’re an experienced user, and you’re looking for the detector most tuned to treasure hunting, this might be the answer.

Features

  • Pole-Mounted: Yes.
  • Audio Discrimination: Spectrum.
  • Headphone Jack: Standard.
  • Built-In Speaker: Yes.
  • Waterproof: Yes.
  • Depth: Variable.
  • Ground Balance: Automatic.
  • Display: Digital.
  • Interface: Clicky-buttons and digital menus.

Performance

This has a breakpoint system that makes it a spectrum-tone, variable-depth detector. If it’s less than a few feet down, you can and will find it. With the advanced digital display and the ease of handling, this is an excellent treasure hunting detector for the really devoted hobbyist.

Pros Cons
  • Easy to use.
  • Automatic ground balancing. 
  • Waterproof. 
  • Comfortable handling pole. 
  • Variability. Wow-level variability.
  • Feels ever so slightly frail.

Conclusion 

This is the penultimate treasure hunting detector. It will find it if it’s there. I want this. Is it too soon to start my next Christmas wish list?

Bounty Hunter Land Ranger Pro: Check the current price

Comparative Chart of Metal Detectors

Product Features

Bounty Hunter Tracker IV

Pole-Mounted: Yes.
Audio Discrimination: 2-tone.
Headphone Jack: 1/4”
Built-In Speaker: Yes.
Waterproof: Yes.
Depth: Coin-sized items at 8 inches, larger objects at 2 feet.
Ground Balance: Automatic.
Display: Gauge.
Interface: Switch dials.

NATIONAL GEOGRAPHIC

Pole-Mounted: Yes.
Audio Discrimination: 2-tone.
Headphone Jack: Standard.
Built-In Speaker: Yes.
Waterproof: Yes.
Depth: Coin-sized items at 12 inches, larger objects at 3 feet.
Ground Balance: Automatic.
Display: Digital.
Interface: Membrane buttons with computer display menus.

Fisher

Pole-Mounted: Yes.
Audio Discrimination: 2-tone.
Headphone Jack: Standard.
Built-In Speaker: Yes.
Waterproof: Yes.
Depth: 9”, 1.5’ for large objects.
Ground Balance: Automatic.
Display: Digital.
Interface: Clicky-buttons and digital menus.

Garrett

Pole-Mounted: Yes.
Audio Discrimination: 2-tone.
Headphone Jack: Standard.
Built-In Speaker: Yes.
Waterproof: Yes.
Depth: 8-10”, 2.5’ for large objects.
Ground Balance: Automatic.
Display: Digital.
Interface: Clicky-buttons and digital menus.

Bounty Hunter Land Ranger Pro

Pole-Mounted: Yes.
Audio Discrimination: Spectrum.
Headphone Jack: Standard.
Built-In Speaker: Yes.
Waterproof: Yes.
Depth: Variable.
Ground Balance: Automatic.
Display: Digital.
Interface: Clicky-buttons and digital menus.

FAQ

Are metal detectors safe?
Absolutely. Magnetic fields used by these have no affect on human bodies, and can’t cause fires. Just, don’t hit someone with it!

Are these devices harmful for pregnant? Can it hurt a baby?
Nope!

Are they waterproof?
Most of them.

Why are metal detectors bad in schools?
Well, they’re not bad … they’re so present because of the collective kneejerk reaction to violent incidents. They’re an inconvenience, but you should probably be glad they’re there honestly.

Can it detect gold/titanium/platinum/lead/copper/mercury/stainless steel/diamond/tungsten?
In the order asked, yes, sometimes, yes, yes, yes, yes, not really, no, usually.

Can a metal detector detect a skeleton?
No. The body you buried is safe.

Can it find keys?
Usually.

Can this device detect alcohol?
No, you need a breathalyzer for that.

Can it detect weed?
No, no it can’t.

Can it detect mobile phone?
Yeah, they contain a lot of conductive metal.

Can I make a metal detector?
You could, but it’d be very basic. I did it once. It’s a neat gee whiz project, but … no substitute for a good detector.

Is there a detector for wood?
No … wood isn’t metal.

What’s the best for a beach?
Any of the ones on this list would be excellent for beaches. Sand is easy to scan through.

A Brief History of Metal Detectors

Metal detection has its roots back in the curiosity scientists had regarding electromagnetism and its relationship to metals in the late 18th century/early 19th century. The first functioning device was developed by Alexander Graham Bell (of telephone fame), which was used to try to find a bullet in President James Garfield’s chest. It did work, but the metal springs in Garfield’s mattress confused it, resulting in a failure.

The modern metal detector came about in the 1920s, thanks to the efforts of scientists such as Józef Stanisław Kosacki. Modern detectors are just improvements on these original concepts (used for mine detection and archaeology), improved with materials sciences and circuitry.

Pros & Cons

Pros

  • Excellent way to find hidden/lost metallic objects.
  • A fun hobby that gets you out, with the promise of finding treasures. 
  • Excellent security and food safety measure.

Cons

  • Not all metals are detectable.
  • Limited range.
  • Devices are costly.
  • Requires patience.

Conclusion

Metal detectors are an example of a long-matured, yet still evolving technology with a multitude of applications. As a former hobbyist, I can tell you that it can be fun, and the joy of finding something is exhilarating even if it’s not a small fortune. For security and health, this is a technology that’s critical and always has been. The ones we looked at today are mostly hobbyist and industrial in use, but with a little ingenuity, you could use these for any implementation.