Metal Detector vs. Magnetometer: Is There A Difference?

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Cory Haasnoot

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If you are looking up the best metal detectors on the market, you probably have seen the word “magnetometerâ€, thrown around pretty frequently. However, while these terms tend to be used interchangeably, it is important to realize that they are technically not the same thing.

Is there a difference between metal detectors and magnetometers? Yes, metal detectors only find metal nearby, while magnetometers find magnetic fields. However, their uses often overlap.

Keep reading to get a better understanding of both metal detectors and magnetometers so you know which tool is right for your needs.


How Do Magnetometers Work?

A magnetometer, at its most basic level, is simply any tool that measures nearby magnetic fields in terms of:

ï‚· Strength
ï‚· Location
ï‚· Type

In order to do this, magnetometers simply contain magnets and supportive components. The magnets’ reaction in a given situation will give information about this magnetic field. This can be used for various purposes. The big advantage of magnetometers is their ability to find these fields over large distances. So large, in fact, that they extend past the Earth itself with the more powerful magnetometers.


How Do Metal Detectors Work?

On the contrary, metal detectors, as the name implies, are only designed to find metal, not magnetic fields. Metal detectors can be made both by using magnetometers or by producing a small electric current.

Electric Current Metal Detectors

Most metal detectors are not magnetometers, they are electric. Why? They are much stronger and more accurate, as long as they are at a closer distance. Electric current metal detectors are able to pick up any metals that conduct electricity (ferrous metals), such as:

ï‚· Steel
ï‚· Carbon
ï‚· Alloy
ï‚· Cast iron
ï‚· Wrought iron

Most metals that conduct electricity are also magnetic, but not all of them.

Magnetometer Metal Detectors

Magnetometer metal detectors will only pick up magnetic metals, regardless of whether they conduct electricity. If your goal, depending on the application, is to find a metal that is magnetic, this will greatly increase your range. However, here is a list of common magnetic metals so you can compare them with the ferrous ones:

ï‚· Carbon
ï‚· Alloy
ï‚· Iron
ï‚· Nickel
ï‚· Cobalt

As you can see, some magnetic metals are also ferrous, which means they will be picked up by both a magnetometer metal detector and an electric current metal detector. If you are looking for one of these at distances of just a few feet, purchase whichever detector is the cheapest. At longer distances, you should opt for the magnetometer.

Of course, if you are looking for nickel or cobalt, you will have no choice but to stick with the magnetometer. Likewise, if your goal is steel you will need to buy an electric current metal detector and hope it is within range.


Digging Deeper: How Metal Detectors Work  a Comprehensive Guide


Which One Should I Buy?

If you know which specific metal you are looking for, you will know right away which kind of metal detector you will need. However, most of us are not non-organic chemistry majors and thus do not know what specific type of metal we are looking for. We just know the name of the object. If so, let’s run through which type of metal detector you will need for your own use:

Searching the Backyard for Gold

Human hands are swinging bottles that contain pure gold minerals found in mines.

If you are buying a small handheld metal detector so you can find some hidden treasure in your backyard (or at the beach) you definitely will want to stick with the magnetometer metal detector. Gold can conduct electricity and does weakly repel magnetism. It is hard to find, hence its value.


Finding Metal Spikes in Trees or Fences

Old wooden fence

Before you take a chainsaw to that 100-year-old tree in your backyard or your old wooden fence, it is a safe idea to check and make sure there are no metal spikes or bolts hidden inside them. In a tree especially, the trunk could have grown around and concealed the metal long ago.

For this, you will want to use an electric metal detector. Spikes and other man-made bolt materials are typically made out of steel, so electric will do just fine, especially at close range. You could buy a magnetometer metal detector if you prefer, but steel is not a material you want to miss.


Security

Airport security checking one of passengers with metal detector on entrance

If you are thinking about getting large, walk-through metal detectors for your place of business, the answer is a bit more nuanced. While magnetometer metal detectors would work in theory, they are not really able to hone in on every metal you want to find in these cases.

While they are gaining traction in some locations, electric current metal detectors are generally considered the tried and true version at places like:

ï‚· Airports
ï‚· Museums
ï‚· Government buildings
ï‚· Vaults

To figure out further which walk-through metal detector you will need, it is best to consult a security expert or local law enforcement.


The Best Personal Use Metal Detectors on the Market

Minelab E- Trac metal detector.

But for all other metal detectors, the ones designed for personal uses, we can run through the best options before you buy. These can generally be broken down into:

1. Magnetometer Metal Detectors
2. Electric Metal Detectors
3. Job Site Durable Metal Detectors

1. Magnetometer Metal Detectors

ï‚· SUNPOW – While primarily a magnetometer, this detector also has the option of switching over to electric for some metals. It is a ground range of 8.7 inches and includes anti-interference technology.

ï‚· Garrett – Heading underwater looking for pirate treasure? Check out this waterproof metal detector that lets you point in very specific directions for stronger focus. It will do great in shallow water conditions, up to 10 feet.

This is great if you already have a good idea where your treasure is and just need to narrow it down. But if you are just heading to the bottom of your local lake to browse? Options with wider detection ranges exist.

2. Electric Metal Detectors

ï‚· OMMO– Since it is electric current based, the Ommo is a bit more accurate than the previous metal detectors, but with a smaller range. It also tells you what specific kind of metal is found, and all for a fair price.

ï‚· Bounty Hunter– This top-of-the-line detector will not only tell you if it found something but how far away or deep the object is too. It also has a comfortable grip even while conducting its own computerized balancing with the ground to ensure it stays focused and accurate. It is expensive, twice the price of the average detector, but they offer a payment plan if need be.


Job Site Metal Detectors

Top view on the construction site of residential buildings during the construction process with two workers standing with drawings

Not everybody is hoping to hit it big by walking the beach. If you need a metal detector on the job site, odds are you do not want something big and bulky. You want one with pinpoint accuracy, so you can point it at a wall or other surface to check for any surprises before you cut.

For this usage, check out these metal detectors:

ï‚· PudiBe Cheap and easy-to-use metal detector is great for the job site. Just point it at the wall and find that beam or tool that went missing. It also offers a vibration mode so you do not have to keep listening to the beep.

ï‚· Minelab This no-frills point-and-shoot metal detector is waterproof all the way down to 10 feet (3 m) and also has an LED flashlight.

ï‚· Lumber Wizard 5 A quick way to ruin your table saw is to run a piece of wood through it that contains a hidden nail. If you are about to cut old, recycled wood, run this handheld metal detector over it first and you will be good to go.


Digging Deeper: Metal Detector vs. Magnetic Locator


Do You Need to Buy Something?

Those products all have a wide range of uses and are fairly priced. However, you may be asking yourself, “Do I really need to buy something?†Well technically no. While the metal detectors online are typically very accurate and durable, there are plenty of household ways you can detect naturally occurring metal via both magnetic field detection and electric current sustainability.


Make Your Own Magnetometer

To make your own magnetometer (for metal detection or otherwise) at home, you will need:

ï‚· A battery
ï‚· Some wire
ï‚· A magnet

Simply attach one end of the wire to the positive side of the battery and the other end to the negative side. The circuit is now actively sending electricity, derived from electrons, through the wire. (So be careful by the way.)

A rotating magnetic field is generated around the wire. Use your magnet to test it out: When it is nearby, this should disrupt the circuit. Thus the system is visibly disrupted by magnets.

Make Your Own Electric Metal Detector

Here’s how you make a metal detector with a radio. To create a more reliable electric current metal detector, you will need:

ï‚· Small AM radio
ï‚· Calculator
ï‚· Empty CD case
ï‚· Velcro

First, take out the insert that actually holds the CD, so you are just left with the blank cover. Then stick the hook part of the Velcro to the middle of the inside of the CD case. Put the soft side of the Velcro on the back of the radio. Now stick the radio and case together. After that, repeat the same process to Velcro stick the calculator to the other side of the CD case.

Once you have all that done, turn on the AM radio and switch the frequency to the highest level it can go without a station. Turn up the volume so all you hear is clear static. Now, believe it or not, when you hold this contraption up to metal, the sound on the radio will change! Static will temporarily change to a louder, more solid tone. When you move your new metal detector away, the static will come back.

Surprisingly Fun Places to Use Your Metal Detector

We have already discussed the two most common places to use a metal detector: in your backyard and at the beach. Whether you bought your metal detector or you made it yourself, just remember that there are plenty of other places to use it.


Digging Deeper: 13 Common Places To Go Metal Detecting


Under Grandstands and Bleachers

Bleachers are not the most comfortable seats and once you drop something, it feels like it is lost forever. If you have got a metal detector though, you can go down there and find it. Or, even better, you can go down there and look for all the loose change that slipped out of people’s pockets during the game while they were too excited to realize it.

We are not necessarily talking huge sums here, but this can certainly be fun for the hobbyist. Just make sure you get permission from the property manager first before you start snooping around.

Ice Cream Truck Route

I am sure you already hear the ice cream truck song in your head as you picture it rolling through your local neighborhood. By now you may already know the route it takes just from hearing it slowly weave its way through the nearby streets. If so, try walking around that route and you are almost guaranteed to find more change than other blocks.

Think about it: kids (and adults) running with cash and then focused on keeping their ice cream from melting all over their hands. Who has the time to pick up the nickels and pennies they drop along the way? You do.

Camp Sites

Campsite With Pitched Tents And Campervan

Keeping in mind that items of significant value should be returned to their rightful owners, people do happen to drop items like:

ï‚· Coins
ï‚· Tools
ï‚· Gear

In Autumn, in particular, campers frequently drop things that quickly get lost in the leaves. If you are that person, buying an inexpensive, pinpoint metal detector could totally save the day. Did you drop a piece of your tent in the leaves?

A metal detector will help find it way faster than digging around with your bare hands. In addition, it can sometimes be fun to see what kinds of things the last campers might have left behind. Maybe they dropped a hammer or a fishing pole, for example. If there are vending machines on-site, flash your detector underneath them too for some free change.


Not All Magnetometers Are Metal Detectors

It is important to note, especially if you plan on buying or constructing your own metal detector, that not all magnetometers can even be used to find metal. Why? Not all objects that produce magnetic fields are made out of metal. There is a large variety of things, from small objects to large astronomical phenomena, that can be picked up by various versions of magnetometers.

These applications include:

1. Compasses
2. Airplane attitude and heading readings
3. Mining exploration
4. Archaeology
5. Water exploration

1. Compasses

azimuth compass

A compass is really just a free-floating magnet on a dial. So what makes that magnet spin? The Earth’s magnetic field of course. That is why the magnet on a compass always points north towards the Earth’s Magnetic North Pole. In this sense, a compass is quite literally a very simple magnetometer.

2. Airplane Attitude and Heading Readings

Thanks to the Earth’s magnetic field, magnetometers can be used for a lot of helpful navigational purposes, not just your own handheld compass. Sure you may have a compass in your car, but navigation is way more important in an airplane. Planes are fitted with quite a few magnetometers on their instrument panels, the most important ones being for heading and attitude.

Using the same principle as a compass, heading sensors are able to determine, based on following the plane’s direction, which way the plane is going. When applying this information to a map or GPS, the pilot can determine where the plane is going. The autopilot can also use the heading reading to make sure the plane is on track towards the correct destination.

Attitude has nothing to do with a plane’s personality. It actually determines, in the simplest terms, whether a plane is headed up or down relative to the ground. On clear days this might seem obvious: are you seeing blue skies or are you headed towards doom?

However, in foggy or other bad weather conditions, making sure you are level is not that easy. That is where a plane’s attitude sensor comes in. By measuring the Earth’s magnetic field relative to the plane, it can determine if you are changing altitude over distance, which would be caused by not being level.

3. Mining Exploration

On the other hand, the ground is a much more welcome sight when it comes to mining exploration. Magnetometers are not used as much in well-established mines. However, they are absolutely crucial in a brand new mine or when a current mine runs low on production.

First of all, while sometimes a hiker gets lucky and happens upon some coal or zinc in the woods, usually new mines are discovered by science. Large magnetometer searching will narrow down the location of magnetic rocks or minerals (metals in their raw form).

Once a location is established and necessary permits are received, more powerful magnetometers with a narrower focus is used to find the specific pockets of valuable materials without digging up the land and wasting valuable:

ï‚· Man-hours
ï‚· Equipment and tools
ï‚· Natural resources such as trees (as well as causing water pollution)

For previously existing mines, magnetometers can serve a similar purpose. Not being able to find the next pocket of minerals could be throwing money away on manpower. By being armed with even a small, handheld magnetometer, miners can easily track down the next pocket and get digging.

4. Archaeology

Rare rocks and minerals are not the only things you can find in the ground. Fossils, valuable in their own way, are also frequently found using magnetometers. Since pieces of fossils can often be spread out, this helps find all of or at least most of the skeletal remains much quicker than digging up a large area.

5. Water Exploration

Shipwreck of the Kormoran

Similarly, while it is easier to look through the ocean than the soil, water presents its own challenges in navigation. Never is this more apparent than when a shipwreck is being searched for. Old pirate ship or a modern tragic accident, vessels can be found without scouring the whole seafloor using special magnetometers. These industrial-strength tools can find man-made components even at the average ocean depth.

The navy also uses magnetometers in their submarines as an alternative to radar. Magnetometers have multiple uses in submarines such as:

ï‚· Heading
ï‚· Depth
ï‚· Locating friendly and enemy submarines

While navigation is key, being able to see enemy ships and submarines long before they see you is critical to the defense. That being said, the specific technology behind the more powerful navy magnetometers are often secret.

Therefore, if you are using a very strong or sensitive magnetometer, make sure you are certain you are actually finding what you need to detect and not one of the above-mentioned objects or phenomena. If you are dealing with small objects, like at the job site or in the backyard, it makes sense to use a smaller magnetometer with pinpoint accuracy.


Digging Deeper: How to Metal Detect Underwater


When Metal Detectors and Magnetometers Fail

Of course, there will always be important things people will need to be looking for, from both a discovery and security standpoint, that do not conduct electricity and are not magnetic.

An item like a glass bottle on a beach, for example, does not fit either category but you still want to find it nonetheless. Let’s walk through some additional methods you can use when both metal detectors and magnetometers are not as effective.


GPS

GPS stands for “Global Positioning System.†You probably already know it well from when you need to drive somewhere new. Just put the address into Google Maps, which uses GPS to both tell you where you are and direct you to where you need to be. This system triangulates your location by measuring your distance to orbital satellites. So nothing to do with magnets or electricity (well, besides charging your device).

This can come in handy if you know where some hidden goodies might be on a beach, but they are not made of metal. For instance, exact latitude and longitude coordinates can be entered into GPS to bring you to the exact right spot much more reliably than a compass.

In addition, GPS can be a valuable additional navigation tool for sailors and pilots. Conveniently, you do not have to worry about wasting your cell phone battery or data either. Check out this standalone GPS device that is also a watch! These products in general have only gotten massively cheaper since their initial invention.


Sonar

Digital blue realistic radar with targets on monitor in searching. Air search . Military search system . Navigation interface wallpaper . Navy sonar.

Although sonar and GPS sometimes get thrown around interchangeably when it comes to navigation at sea, in reality, their underlying technologies have nothing to do with each other. Sonar sends out a small sound signal and listens for them to bounce back.

The way in which these signals come back, and the degree to which they have been disturbed, can be used to tell the user the distance of nearby objects in the water. Technically this is another really popular tool for submarines (besides magnetometers).

However, on a smaller scale, inexpensive sonar devices are used by people trying to find and catch fish. Metal detectors and magnetometers would be useless trying to catch fish, so here are some great sonar devices:

ï‚· HOOK 2 At a very reasonable price, this sonar device does it all. Many lake maps are already installed and with multiple views of various depths.

ï‚· Garmin Not as many options, but still has an impressive range. Significantly cheaper but gets the job done.

ï‚· Deeper This neat new device bobs directly and your string and sends sonar information back to your phone via Wi-Fi. 21 st century fish finding at its finest.


Sluice Boxes

Sluice box set up in scenic riverbed. Panning and mining for gold and gemstones. Adventure and fun in prospecting for gold. Beautiful outdoor setting, woods, river and rocky mountain stream.

Do you know all that grainy black and white footage of guys searching for gold in the stream armed with nothing but a metal tray? That is a sluice box. Believe it or not, you can still buy a sluice box today!

Even though they are now made of durable steel, their basic design has not changed since their inception 150 years ago. It is hard to find gold with a metal detector and/or a magnetometer anyway. If you have a hunch that some might be in a stream or river, sometimes you just need to get in there with a sluice box and get your hands dirty.


Digging Deeper: How to Pan For Gold


To use a sluice box, simply scoop up some suspicious-looking dirt. Next, carefully pour out the water itself. You will be left with dirt and, hopefully, gold. By shaking the box, the dirt will be sorted through the perforated plates, leaving just the precious stones remaining up top. Simple but effective.


Conclusion – Metal Detector vs Magnetometer

Well, that’s the scoop about metal detectors and magnetometers and how they are different but similar. I hope you enjoyed this article and if you have any questions or comments feel free to leave them in the comments section below. Until next time Happy Treasure Hunting!

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Author: Cory Haasnoot

Cory Haasnoot is an author, entrepreneur, metal detecting enthusiast, antique, coin collector, and founder of Treasure Seekr.

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