Let’s be honest, no one likes waiting in line at security checkpoints. But those walk through metal detectors you pass through at airports, government buildings, or stadium entrances? They’re not just sitting there for show. These sophisticated devices are essential tools for keeping people safe by identifying metallic objects that could pose security threats, from concealed weapons to metal objects tucked away in clothing or bags.
Understanding what walk through metal detectors detect helps everyone involved, security professionals, private facilities, and the general public, make smarter, safer decisions. Whether you’re running security operations at a courthouse or just trying to get through airport security a bit faster, knowing how these security devices work is a serious advantage.
At Garrett, we’ve spent decades developing world-class metal detection technology. Our detectors, both walk through and handheld metal detectors, are built for reliable performance in various settings, from high security environments to more everyday security screening scenarios. And we’re here to break it all down in plain language.
Key Takeaways
- Walk-through metal detectors use magnetic fields and pulse induction technology to detect a wide range of metallic objects.
- These devices can detect ferrous, non-ferrous, and alloy metals found in weapons, tools, electronics, and everyday items.
- While detectors can’t identify non-metallic threats, they’re critical tools in a layered security screening strategy.
- Advanced detectors feature accurate multi-target detection, AI-powered precision zone indication, and can integrate with other screening systems for simultaneous multi-sensor detection.
- Garrett is a global leader in metal detection, offering high-performance solutions like the PD 6500i, Multi Zone, and Paragon for security professionals worldwide.
How Walk Through Metal Detectors Work
Magnetic Field Detection
Let’s start with the basics. Most standard metal detectors use an magnetic field to spot metallic items. Inside each unit panel, there’s a search coil that sends out an invisible field. As a person walks through the archway, if they’re carrying metal objects, those items disrupt the field. That disruption? It’s the signal.
The receiver coil, typically housed in the opposite panel, picks up on this change in the magnetic field, and voilà, you get an alert. Whether it’s a classic metal detector at a stadium or a high-end unit in a courthouse, that’s how metal detectors work. And yes, even your belt buckle or loose change can trigger an alert if the detection capabilities are sensitive enough.Garrett detectors like the Paragon and PD 6500i have transmit and receive coils in both panels – this design is called bilateral detection and it results in detection that is more fully characterized (like binocular vision but for metal detection) and more even, since the field strength does not diminish across the portal due to greater distance like it does in competing detectors.
Multi-Zone Detection for Precision
Now, here’s where advanced technology really shines. Instead of treating the entire doorway as one big detection area, what we call a single zone, our walk-through metal detectors like the Paragon are equipped with multiple detection zones. Particularly, the Paragon has 66 detection zones, 22 vertical bands for left, right, and center identification.
So why does that matter? Well, if a detector only tells you something is wrong, but not where, you’ve got a guessing game on your hands. But when you’ve got simultaneous detection and pinpoint location tracking, you can alert security personnel to the exact location of the threat on a person’s body.
This level of precise threat detection reduces unnecessary pat-downs, limits delays, and helps your security staff focus on potential threats that actually matter. Plus, it makes life easier in security applications where time is money, like airport security, public events, and busy correctional facilities.
What Types of Metals Can Be Detected?
Ferrous Metals
Alright, let’s talk about the obvious stuff first, ferrous metals. These are metals that contain iron, like steel, and they’re highly magnetic. When metal detectors detect these, they’re reacting to the strong magnetic signal these items give off. You’ll find ferrous metals in things like:
- Firearms
- Pocket knives
- Tools
- Reinforced belt buckles
- Steel-toed boots
Because of their strong magnetic properties, these are usually the first items caught by even a basic metal detector. If you’re in high security environments, detecting these quickly is non-negotiable.
Non-Ferrous Metals
Next up: non ferrous metals. These include aluminum, brass, copper, and even precious metals like gold and silver. These don’t contain iron, so they’re less magnetic, but they’re still conductive. Common items made from non ferrous metals include:
- Aluminum handguns
- Brass knuckles
- Copper casings
- Jewelry
- Mobile phones
Detecting these requires a bit more finesse. Not every classic metal detector is up to the task, but with our advanced features, you can catch even the trickiest materials. This is especially important in security checkpoints where concealed metallic objects might be disguised as personal electronics or accessories.
Alloys and Mixed-Metal Objects
Of course, real life isn’t neatly categorized. A lot of modern threats come in the form of metallic items that blend both ferrous and non-ferrous metals. These might be concealed weapons with alloy parts or custom tools built to evade detection.
The challenge? These items may not trigger older detectors. But our walk-through metal detectors means even these hybrids are unlikely to slip through undetected. We’ve designed our systems to handle multiple objects at once, adapt to metal detection noise in real time, and reduce false positives by understanding the behavior of metal objects across different zones.
Common Objects Detected by Walk Through Metal Detectors
Walk-through metal detectors are built to spot metallic objects, plain and simple. But there’s more nuance than you might expect. Not all metal objects are dangerous, and not all security threats are obvious. As a company that’s helped secure government buildings, correctional facilities, stadiums, and schools, we understand the tightrope act.
So, what do walk-through metal detectors detect? That’s the question on everyone’s mind, and the answer depends on the metal detection technology, the detection capabilities of the unit, and how it’s used by trained security professionals. Let’s break it down.
Threat-Related Items
First up: items that require immediate attention. These are the concealed weapons, tools, and components that set off every alarm bell.
- Firearms and ammunition: No matter how cleverly disguised (or disassembled), most guns contain metal components easily picked up by even a standard metal detector.
- Knives and blades: These show up fast, especially in units with multiple detection zones that pinpoint the exact location on the person’s body. Most knives require higher security settings to catch than most guns.
- Explosive components: Many devices include wiring or metallic items that allow a metal detector to raise the red flag. Explosive construction varies wildly, as do the settings required to catch them.
- Improvised weapons: Construction tools, kitchen knives, metallic shivs, and even stationery like scissors can be deadly. A metal detector can catch these potential threats, but staff will have to determine if they are a true danger or ultimately innocuous items.
These are the kinds of items that alert security personnel instantly, where the difference between accurate detection and a false alarm matters. In high security environments, every second counts.
Personal and Everyday Items
Here’s where it gets complicated. Metal detectors work by scanning for any metal. That means a lot of harmless objects can trigger alerts too, depending on your settings.
- Keys, coins, mobile phones: Yep, common culprits that pop up in every security line. The Quick-Q program of the Paragon and PD 6500i is designed to let these through while still catching the guns and large knives that are relevant to many security applications.
- Jewelry, belt buckles, eyeglasses: These often contain precious metals or other ferrous metals.
- Smartwatches, earbuds, and USBs: Not dangerous like weapons are, but all of these can be valid threats in some markets – a rogue USB drive in a data center is a huge potential threat.. Some earbuds have extremely low metallic content and won’t alarm except on the highest prisons or loss prevention settings..
Fortunately, you don’t have to detect all of these, all the time. Good security settings are all about determining the appropriate level of threat object discrimination. Metal detectors can find even incredibly low-metal objects like a single earbud, but you can tell them not to alarm on objects that aren’t important to your security operation.
Some older or more primitive metal detectors (sometimes called weapons detectors) can’t find these smaller objects or smaller weapons at all, but more sophisticated detectors simply have to adjust their settings to achieve the appropriate balance between threat detection and non-threat elimination for your facility.
Tools and Miscellaneous Items
Ever seen a toolbelt go through a metal detector? It’s a symphony of alarms.
- Construction tools: Things like nails, screwdrivers, and utility knives are common in work settings.
- Concealed metallic objects in shoes or clothing: Some people don’t even know what’s in their gear.
When you’re dealing with multiple objects and large crowds, you need something that handles the job with reliable performance. The Garrett Paragon does just that. Its advanced features include 66detection zones, bilateral screening, and AI-powered precision multi-target indication. Whether you’re at a concert, a school, or airport security, it’s built for high flow without compromising precision.
What Walk Through Metal Detectors Don’t Detect
Even the best security metal detectors have their limits. They’re based on physics, so they perform reliably and predictably, but they don’t do everything.
Non-Metallic Threats
Not everything dangerous contains metal. And yes, that’s a little unsettling.
- Plastics, ceramics, 3D-printed weapons: they can pass through unnoticed. Notably, many versions of these threats still contain detectable metallic components to improve rigidity and durability.
- These may require security devices like full-body scanners, x-ray machines, or explosives trace detection units to identify.
That’s why seasoned security personnel use a layered approach. One device can’t do it all. It’s about combining tools and trusting your team’s instincts. However, the overwhelming majority of threats contain detectable quantities of metal, which is why metal detectors are such a common sight in security checkpoints at all levels of security.
Why Our Clients Choose Garrett For Walk Through Metal Detectors
This isn’t our first rodeo. Garrett has been innovating in the metal detection space for decades, and while the technology has evolved, our mission hasn’t: help security professionals keep people safe.
Decades of Security Innovation
From the early days of the LA Olympic Games security to the internationally-recognized performance and advanced feature sets of today, Garrett has been there, done that. We’ve helped build the foundation for modern security checkpoints across the globe, from airport security to high security environments in the private sector. Here’s a quick look at our lineup, because picking the right detector shouldn’t be difficult:
- PD 6500i: A top-tier unit with 33 multiple detection zones and lightning-fast screening. Perfect for high throughput environments. The PD 6500i is a reliable detector that has been certified globally, including TSA and ECAC certifications. It suits a wide range of security applications.
- Multi Zone: Lightweight, reliable, and cost-effective. Ideal for small venues, events, and various settings that need specific security without an initial investment headache. The Multi Zone features American made quality but at a global price point.
- Paragon: For those who like data with their safety. The Paragon offers statistical analysis, smart threat detection, and fast boot up times. It integrates seamlessly with your security needs, includes AI-powered detection, zero touch NFC technology, and accessories like the SecureFlow Kiosk. The Paragon is our top of the line walkthrough detector. Please note: The Paragon is still going through the TSA certification process.
Every walk-through metal detector of ours is packed with key features that help detect metal objects and potential threats while ignoring the non-threats that would slow your screening down
Recap: What Walk Through Metal Detectors Can (And Cannot) Detect
So, what do walk-through metal detectors detect? It’s more than just knives and guns. They can detect metallic objects like precious metals, ferrous metals, electronic components, and concealed weapons, even if they’re buried under layers of clothing or gear or hidden inside the human body.
Curious about which model fits your needs and budget? We get it, initial investment matters, especially when you’re balancing safety with throughput. Let’s talk. Whether it’s a walkthrough for a busy venue or a handheld for roaming staff, We are here to help.Got questions? Need help building a smart, flexible screening plan? Let’s talk. At Garrett, we don’t just build security devices, we help build enhanced security you can trust.
