How Do Metal Detectors in An Airport Work?

Every person walking into an airport must do so through a metal detector, and all items must pass through an X-ray machine. Before boarding your flight, it is a protocol that you must go through a body scanner.

Even if you are not carrying anything along, the metal detector may still flag you. This might leave you wondering what it is exactly that metal detectors detect in the airport. There is no need to keep wondering about that as this post will provide all the answers you need.

How Do Metal Detectors in An Airport Work?

What do airport metal detectors detect?

The metal detectors in the airport use electromagnetic field to detect metals. Metals like iron, cobalt, and others produce disturbances, when placed in a magnetic field. This will prompt the user that the detector has found something.

Apart from detectors, airports also use scanners. The body scanners detect non-metallic items that the detector might have missed. The scanner is used for full body, and known as the millimeter wave.

This machine does not see the naked body, and cannot do the work of an X-ray. It only provides the animated image of where something may be hidden on the body of a person.

Hair extensions, pins, piercings, underwire brassiere, and so on can get you flagged in the scanner. Once they have discovered what it is, you will be released to go.

If you want to avoid getting flagged by the scanner, you will have to avoid all these things. Dress very simple and remove everything that might be in your pocket. You might want to also these post AT Max vs Garrett AT Pro Metal Detector Reviews and Ultimate Guide on How to Calibrate a Metal Detector

How do Metal Detectors Work?

Metal detectors work, based on the science of electromagnetism. Almost all the ones in the airport are based on pulse induction. The PI is a powerful system that uses a coil of wire on each side of the arch.

These coils of wire represent the transmitter and receiver. It sends short powerful pulses of currents through these coils and each pulse generates a bit of magnetic field.

Once the pulse comes to an end, the field reverses polarity and collapses. This results in a sharp electrical spike which will last for some seconds. This also causes a new current to run through the coil.

This new current is known as the reflected pulse, and will also last for some seconds. It sends another pulse again and repeats the process.

An average PI detector sends up to a hundred pulse every second. However, the number of pulse can range from 25 to a thousand, depending on the manufacturer.

Model of the metal detector is also another determinant of the number of pulse a PI detector can send.

Every metal detector works by transmitting electromagnetic field through the coil into the ground. If there are any metal objects within that area, it will have energy and also transmit another electromagnetic field. Once the coil receives this field, it alerts the user by making a bleeping sound.

What metals do airport metal detectors detect?

Every metal detector uses electromagnetic to detect and alert the presence of metal objects on a person. These devices can do this either actively or passively.

Nickel, Iron, and cobalt can be detected by active and passive detectors. On the other hand, copper, aluminum, and brass are only detected by active detectors.  

The airport detectors pose as security and look out for those boarding the plane.

It can also detect weapons like gun, knives, explosives, and so on. It will alert the user if any passenger is carrying something that might pose as a threat to the lives of other passengers.

The active detection generates a time magnetic field either by using a handheld detector or walking through own to determine the amount of metals present on the body of a person. The passive detection, on the other hand, will measure any changes in the grounds magnetic field is caused by the present metal object.

Airport Metal Detectors Jewelry

Metal detectors can be set to either be less sensitive or over-sensitive. When it is less, it will discover only a little bit of metal.

However, if it is over sensitive, it will discover harmless metal. That means that people in the airport will set it off with metals like jewelry, pen, keys, and so on.

This might make it difficult to actually find objects that are likely to threaten human lives in the plane. With this, most detectors do not have a high setting.

Depending on the metal detector you are using, it may not detect any jewelry you have on your body.

There are really no threats of setting off the alarm. This also depends on the size of the jewelry in question, huge chains, big hoops, have high probability of triggering the metal detector.

However, since you do not know how tight the security will be, you are advised not to wear any at all.

Types of metal detectors

There are four types of metal detectors and they are as follows:

  • Beat-frequency Oscillation: This is the most common metal detector used in most stores. It can detect items that are about 2 feet underground. It has a big ring at the base and another one higher from the first. The two coils are linked to the oscillator which produces a frequency.
  • Pulse Induction: This is the latest technology in detecting metals. It is mostly used by personnel to discover hidden weapons at checkpoints.
  • Very Low-frequency detector: This is the most popular detector in use. It is known to be very sensitive as well as accurate. Most treasure seekers use this type of detector. It has a coil which serves as a transmitter, giving electric current, a receiver that picks signal from the main coil, and intensifies it many times.
  • Industrial: This is one of the most common and guaranteed ways of providing security. The most commonly used one is the door frame detector, and can obviously not be used by hobbyists. It is very active as it discovers criminals with weapons right from entrance of a building.

Conclusion on How metal detectors in an airport work?

Finally, that is how metal detector works in an airport. It is advisable to be cautious regarding what we put on or carry along when visiting the airport so we don’t get harassed.

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