Traveling by plane implies going through several phases of control before arriving to board. Some are familiar to all passengers, such as passing through metal detector or luggage inspection, but there are less known procedures that may surprise, even the most experienced travelers, such as this paper strip that is passed on the hands or waist of random passengers.
Strip of paper in your hands or waist
One of these procedures can occur when, after crossing the metal detector, a security agent approaches and passes a small strip of paper through his hands and waist. This action is part of a specific test that aims to reinforce airport safety and prevent threats for both passengers and infrastructure, says the site dedicated mainly to PPLware technology.
This method is known as explosive traces detection test, or explosive trace detection (ETD). This is a measure applied to airports around the world and which, in Portugal, is part of a set of protocols designed to identify residues of potentially dangerous substances.
How the ETD Test works
The procedure is based on the collection of particles that may have been in the hands, clothing, luggage or other personal effects of an individual who has been in contact with explosive material. For this, a cloth or strip of specific material is used, which is passed over the surfaces to inspect, usually in the hands and waist.
The samples collected are then inserted in a detection machine that resorts to most cases to ionic mobility spectrometry technology. This technique warms the sample to release the molecules present and analyzes its mobility when subjected to an electric field. Each substance has a unique chemical signature, which allows quick and accurate identification, refers to the same source.
Immediate results
The result is obtained in a few seconds. If a suspicious substance is detected, the passenger or object is subject to additional inspections. It is important to note that a positive result does not necessarily mean that the person transports explosives as false positives may occur due to compounds with similar chemical composition.
The main advantage of this method is, according to the above source, the high sensitivity, which allows the detection of very small amounts of material. However, its effectiveness depends on the correct collection of samples and regular maintenance of equipment.
Who is selected for the test
The choice of passengers for the ETD test may be totally random or based on behaviors or situations that raise suspicious. This control works as a complement to X-ray scanners and body detection equipment, forming a more complete and efficient safety system.
According to modern airports, ETD is considered fundamental to maintaining a balance between safety and fluidity in passenger processing, ensuring that potential threats are identified without compromising the pace of operations.
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