Why Do People Worry About Watches and Airports
The main worry for watch owners is magnetism. There is a small hairspring inside an automatic watch, which helps it keep time. The coils stick together if this spring gets magnetized.
Thus, this makes the watch run very fast. Metal detectors use magnetic fields to find guns or knives. Many people think these fields are strong enough to hurt a watch. However, scientific data shows this is not true for modern security equipment.
Walk-Through Metal Detectors are Safe
The metal detector arch you walk through does generate a magnetic field. However, it is very weak. A scientific study published in the Journal of Health Physics measured exactly how strong these fields are.
The researchers tested various metal detectors and found that the strongest magnetic field inside a walk-through detector is about 299 Amperes per meter (A/m). In older units, known as Gauss, this is roughly 3.7 Gauss.
The number is very small when you analyze the watch standards. There is an international rule for watches called ISO 764. Therefore, a magnetic watch must withstand a field of 4,800 A/m (about 60 Gauss) and still keep time. That way, the watch handles a magnetic force 16 times stronger than what the airport scanner produces.
- Airport Metal Detector Strength: approximately 300 A/m
- Minimum Watch Resistance (ISO 764): 4,800 A/m
Hand-Held Wands are even Weaker
Sometimes, security staff will use a hand-held wand to scan you. Research found these wands are much weaker than the large arches and produce a magnetic field of only 6 A/m. The force is very slow, which means it is impossible for it to affect a mechanical movement.
X-Ray Baggage Scanners
When you put your watch in the plastic tray, it goes through an X-ray tunnel. X-rays are a type of high-energy light, but they are not magnetic.
These rays pass through the metal case and gears of the watch just like they pass through your bag. However, they can’t magnetize the hairspring or dry out the coil.
The only magnetic part of an X-ray machine is the motor that moves the conveyor belt. However, your watch sits on the belt, far away from the motor coils. So, there is no risk.
What About Vintage Watches
Most watches made after the 1960s use modern alloys like Nivarox for their hairspring. These are naturally hard to magnetize.
If you have a very old watch from the 1940s or earlier, it might use a “blue-steel” hairspring. These are more sensitive. However, 3.7 Gauss is a low number even for these old watches.
A standard magnetic field is usually stronger than an airport scanner. If you are worried about a rare vintage timepiece, you can ask for a hand search, but physically, the risk is low.
Also Read: Water Damage in Watches: How Bad it Can Get
Wear Your Watch Through the Airport Without Worry
You can wear your Rolex, Audemars Piguet, Richard Mille, Omega, or Seiko through the airport without stress. The science proves that the magnetic field is too weak to break the ISO 764 limit, and X-rays don’t interact with the movement at all.
References
- Boivin, W., Coletta, J., & Kerr, L. (2003). Characterization of the magnetic fields around walk-through and hand-held metal detectors. Health Physics, 84(5), 582–593.
- International Organization for Standardization. (2020). ISO 764:2020 Horology — Magnetic resistant watches. ISO.
