Airport Scanners: What They See And How They Work

Airport scanners are an essential part of airport security, designed to detect potential threats and ensure the safety of passengers and crew. There are two main types: X-ray scanners and millimeter wave scanners. X-ray scanners use low levels of ionizing radiation to create an image of the contents of a passenger's luggage, while millimeter wave scanners use non-ionizing electromagnetic radiation to create a 3D image of a passenger's body. Both types of scanners can detect a wide range of items, including weapons, explosives, liquids, electronic devices, and drugs, and have become an integral part of the airport security system to prevent potential threats and ensure the safety of air travel.

X-ray scanners

The X-rays are absorbed differently by different materials, which allows the scanner to detect a wide range of items, including weapons, explosives, and drugs. X-ray scanners are considered safe for passengers, emitting low levels of radiation that are well below the recommended safety limits.

In addition to detecting metal objects, X-ray scanners can identify non-metallic and organic materials. They can help prevent the smuggling or sale of prohibited food items and drugs. However, they may not directly detect drugs hidden in luggage, but the simulated images they produce can assist security personnel in identifying suspicious items for further inspection.

Millimeter wave scanners

The scanners consist of two rotating antennas or transmitters that produce waves as a person stands inside the machine. The waves pass through the clothing, reflect off the person's skin and any potential threats, and then return to receivers, which send the images to an operator for analysis. The software used in the scanners can interpret the data and present a 3D image of the subject, highlighting any suspicious items.

Overall, millimeter wave scanners are an essential component of airport security, providing a safe and effective way to detect potential threats and ensure the safety of air travel.

Full-body scanners

Millimeter wave scanners emit non-ionizing electromagnetic waves, which are reflected back by the body and detected by the scanner to create a 3D image. This technology can detect a wide range of items, including weapons and explosives, and is considered safe for passengers as it uses low levels of radiation.

Backscatter x-ray scanners, on the other hand, use ionizing radiation to create detailed images. While these scanners can also detect both metallic and non-metallic items, there are concerns about potential health risks associated with ionizing radiation. This type of radiation can cause biological damage at moderate doses and has the potential to cause cancer or other abnormalities. However, the doses of ionizing radiation emitted by backscatter x-ray scanners are exceedingly low, and the health risks are considered trivial.

To protect the privacy of passengers, latest-generation devices use generic body images (matchstick figures) to highlight suspicious areas rather than displaying detailed body images. Additionally, measures have been implemented to blur faces, make images less provocative, and separate security personnel viewing the images from the scanned individuals.

While full-body scanners have faced opposition from religious groups, civil liberties organizations, and privacy advocates, they remain an essential component of airport security, enhancing safety measures and helping to prevent potential threats.

CT scanners

The CT scanner's ability to create a detailed 3D image is particularly useful. This image can be viewed and rotated 360 degrees, allowing for a thorough analysis of the bag's contents. The technology is so advanced that it can automatically detect explosives, including liquids, and distinguish between different materials. This level of precision helps to reduce the number of secondary screenings, as operators can quickly identify and target specific areas for further examination.

In addition to enhancing security, CT scanners also offer operational benefits. They can reduce physical contact and enable better distancing among travellers, especially when paired with systems that have a high belt speed. This not only improves safety in the context of COVID-19 but also increases efficiency by cutting down the number of trays needed and speeding up the screening process.

Overall, CT scanners are an important tool for ensuring the safety and efficiency of airport security systems, providing detailed images that help identify potential threats while also minimising physical contact between individuals and surfaces.

Metal detectors

Oscillators, on the other hand, use an alternating current to generate pulses of radio waves. When the detector is passed over a metal object, eddy currents are induced in the metal, creating a magnetic field that interferes with the frequency of the radio waves. The detector registers this change, indicating a metallic object.

Frequently asked questions