Metal Detectors And Gold: What Gets Detected?

Airport security systems use different screening instruments and metal detectors to ensure the safety of passengers. Metal detectors work by creating magnetic fields through electricity, and if there is any metal, the magnetic radiation will bounce back, resulting in a beeping sound. While small metallic items like watches and buttons are usually ignored, gold jewellery can often trigger the metal detectors and require a further check by TSA. Gold is a metal and will activate the metal detector, although the design will affect whether it sets it off. Gold carried in semi-liquid form, however, may not be detected by airport metal detectors, and there have been instances of gold paste or powder being smuggled through airports.

Gold in a semi-liquid state can evade detection

Gold is a metal and will activate a metal detector. However, the design of the gold item will affect whether it sets off the metal detector more than the material itself. For example, a solid gold bracelet is more likely to set off a metal detector than a linked bracelet of the same weight, as the linked bracelet has gaps that show it is not a large piece of solid metal. Similarly, a large piece of gold jewellery worn around the neck or wrist may not set off a metal detector, but the same item balled up in a hand or pocket is more likely to set off the detector.

The body scanner used at airports is not looking for metal but for extra material of any kind, so it can pick up knives, guns, and bombs strapped to a body.

Density and thickness of gold matter

Gold is a metal that will activate a metal detector. However, the density and thickness of gold matter when it comes to detection. The design of the gold item will determine whether it sets off the metal detector or not. For example, a solid gold bracelet is more likely to set off a metal detector than a linked one, as the gaps in the latter show that it is not a large piece of solid metal.

The size, amount, and shape of the gold item also play a role in detection. A large gold nugget can be found by almost any metal detector, whereas small gold bits that weigh less than a gram are harder to detect. The operating frequency of a metal detector is crucial here: low-frequency detectors are better at finding bigger nuggets and deeper targets, medium-frequency detectors can find both small and big pieces, and high-frequency detectors are better at locating smaller pieces of gold.

The ground conditions also affect a detector's performance. Pulse Induction (PI) metal detectors are ideal for highly mineralized soils and salt water. They can also detect gold at greater depths. VLF detectors, on the other hand, are more suitable for shallow and small targets.

In conclusion, the density and thickness of gold matter when it comes to metal detection. The design, size, and shape of the gold item, as well as the type of detector and ground conditions, all play a role in successful detection.

Gold is a metal and will activate the detector

Gold is a metal, and as such, it will activate a metal detector. Metal detectors are installed in airport scanners, creating magnetic fields in the surroundings through electricity. If there is any metal, the magnetic radiation will bounce back on the walls of the scanner, resulting in a beeping sound. The primary purpose of these scanners is to safely recognise unlawful devices.

Gold is a dense metal with low conductivity, so the high-frequency radiation of the scanner will easily detect it. The scanners create images of the luggage on a digital screen, and metal objects typically appear as dark green or blue. The system also provides an beeping sound when unwanted material is found.

The design of gold jewellery will affect whether it sets off the detector. For example, a solid gold bracelet is more likely to set off the detector than a linked bracelet with gaps. However, the size and amount of gold also play a role. A large amount of gold, even in jewellery form, is more likely to be detected than a small amount.

Airport scanners can also detect gold in paste or semi-liquid form, although this requires more advanced technology. In some cases, gold powder is dissolved in orange-tinted nitric acid and hydrochloric acid (known as aqua regia) and smuggled in this form.

Design of the jewellery matters

The design of your jewellery will play a significant role in determining whether or not it will set off the metal detectors at the airport. Here are some key factors to consider:

Size and Shape

The size and shape of your jewellery can affect whether it triggers the metal detector. Larger, bulkier pieces are more likely to be detected, whereas smaller, delicate items may not be as easily noticed. For example, a solid gold bracelet is more likely to set off the alarm compared to a linked bracelet with gaps, as the latter appears as separate, smaller pieces rather than one large piece of metal.

Thickness and Density

The thickness and density of the gold in your jewellery also come into play. Thicker, denser pieces are more likely to obstruct the passage of electromagnetic waves, increasing the chances of detection. On the other hand, thin, delicate gold chains or necklaces may be less likely to trigger the alarm due to their lower metal content.

Placement on the Body

Where you wear your jewellery can also make a difference. Items worn around the neck or wrist may not always set off the metal detector, but the same piece of jewellery balled up in a pocket or held in the hand is more likely to be detected due to the concentration of metal in one area. Additionally, certain body scanners may not detect body piercings or undergarment wires, so the placement of your jewellery could potentially affect its detectability.

Type of Metal

Although gold is a metal that will activate the detector, not all metals are created equal. Different metals have varying densities and electromagnetic properties, which can affect their detectability. Additionally, some metals may be more commonly associated with specific types of jewellery, and this familiarity could influence the likelihood of detection.

Overall Design and Composition

The overall design and composition of your jewellery piece, including the combination of metals and non-metallic elements, can impact its detectability. For instance, a gold necklace with a large pendant may be more likely to trigger the alarm compared to a simple gold chain due to the pendant's size and potential density.

In summary, while gold jewellery can set off metal detectors at airports, the specific design characteristics, including size, shape, thickness, and placement on the body, will play a significant role in the likelihood of detection. These factors can influence the concentration and arrangement of metal, affecting how easily the electromagnetic waves pass through and whether the detector is triggered.

Gold can be detected in liquid form

Metal detectors at airports do not raise an alarm if gold is carried in a semi-liquid state. This has been a challenge for customs officers trying to curb the smuggling of the precious metal. The gold in paste form is usually concealed in pouches wrapped with adhesive tapes and kept between the rods of trolleys meant for transporting baggage.

However, gold can be detected in liquid form. Airport scanners can detect gold in liquid form because gold is a metallic object with low conductivity, so the high-frequency radiation of the scanner will easily detect it. The scanners are designed to detect narcotics and drugs hidden in luggage or clothing. If you pass through a full-body scanner, electromagnetic waves and radiation will provide an image of any drugs on the screen.

The airport body scanners include a backscatter X-ray machine that has a meagre amount of radiation that reflects off the machine. These electromagnetic waves will detect unlawful metals, devices, explosives, and weapons hidden in your clothes.

The X-ray detectors work by sending a beam of X-rays through the scanned objects. The higher the density, the more X-rays are absorbed, and the fewer are detected on the other side. Gold is denser than most other metals, so it is more opaque to radiation for a fixed thickness.

Frequently asked questions