We’ve seen in movies that excursionists search for buried treasure with metal detectors. Police search for bombs and mines with this device. Bet you wanted one for yourself in childhood.
Other than those, there are also a lot of uses of metal detectors in our daily life. They’re used in important public buildings for security screening. We hear almost every day how metal detectors found out drugs and other illegal things in the airport.
We have to walk through more metal detecting points than doors in an airport. One might come to think if the radiation has any harmful impact on the body. Superstitions about metal detector are not uncommon either.
But from the recent studies, it is clear that the radiation that a metal detector releases have close to no reaction to the human body. In this article, I’ve tried to clarify the point. So if you’re concerned about your health while passing a metal detecting security, you’ll see there’s no reason to be.
Types of Metal Detectors
The electronic instrument which is used to detect the presence of metallic objects by using electromagnetic fields is what we call a metal detector.
We’ve seen metal detectors work in airports, shopping malls, courthouse, public schools, etc. If the sensor detects any metals nearby, it triggers the detector, and we hear an alarm tone going off, the closer the metal, the higher pitched the sound. Different types of metal detectors are available :
a) Walk through Metal Detectors: These types of metal detectors are mostly seen in public buildings, military institutions, airports, etc. They emit electromagnetic waves by the source coil into the detection area. The detector coil discerns these waves.
b) Hand- carried Metal Detectors: These detectors are small which can be handheld. They’re generally used at security checkpoints to pinpoint metal objects whose presence has already been detected by a walk-through system.
c) Gradiometer Metal Detectors: Gradiometer metal detectors draw on the effect of moving magnetic objects on the earth’s magnetic field. These metal detectors are walk-through devices that can also be mounted on vehicles.
d) Magnetic imaging portals: The magnetic imaging portals illuminates its detection area with radio magnetic, electronic waves just like the traditional walk-through metal detectors. A total scan of the detection space can be taken by the time it takes a person to walk through the metal detector. The magnetic imaging portal is preferred as a metal detector rather than as an imaging system because it does not provide a detailed image of the detected metal but only discloses its location and size.
Read also: Can gold be detected by a metal detector?
How does a Metal Detector Work?
We all have seen metal detectors work, but ever wondered how they even detect metal in the first place? It is designed to use electromagnetism in two different ways; active and passive.
The active function requires illuminating the detection space with an electromagnetic field. For example, the walking spaces of walk-through metal detector portal or the area covered by the handheld metal detector.
Metal detectors contain a coil when current is applied to it; the coil creates a magnetic field. If the magnetic field comes near any metallic object, it induces an opposite flow of current in the coil; known as eddy current. It acts as the signal to the detector to detect metal.
And on the other hand, the passive function does not illuminate the detection area, it can quickly detect a ferromagnetic object like iron, cobalt, nickel, etc. but it cannot identify the materials which are not ferromagnetic.
The handheld metal detector works in the same manner. There is a battery on the metal detector, which supplies electricity through the transmitter circuit to the transmitter coil and creates a magnetic field in the process if the detector is swept over any metallic object it goes through the magnetic field and creates another magnetic field.
This travels through the receivers coil up to the receivers’ circuit which makes the alarm go off and alerts you that it found something. All on a sudden, a question can come up on your mind, are metal detectors safe?
Read also: How to clean old coins without devaluing them?
Are Metal Detectors Safe?
The safety of metal detectors is a frequently asked question. We know that people boarding planes have to pass through a thorough check to make sure everyone’s safety while on a plane.
We have seen different kinds of security checks done on people and their luggage’s who travel by plane. An airport has many entrances and exits that one has to come across and all these passes have metal detectors that passengers are required to pass through.
Are metal detectors safe for babies? There has always been an argument over their safety of walk through metal detectors. We wonder whether these detectors cause harm to us; especially to children and pregnant women.
The debate has been sparked out by the way metal detectors work. These detectors are functioned to detect the metals that one could be hiding on. People assume that walk through metal detectors use X-rays which have been proved to be harmful to the pregnant women and also to ordinary users.
X-rays are known to mutate people’s genes causing abnormal births. Pregnant women fear of having miscarriages when they pass through the detector.
Till now, there are no such cases reported about people suffering in one way or other after they have passed via a metal detector. Do metal detectors emit radiation?
Yes, they do. But the energy that is emitted by a metal detector is not dangerous or harmful. In cases of walk through metal detectors, they use low-level x-rays which have been known to be harmless.
These metal detectors are made with considering human bodies. So it is understandable that there is no reason to worry about and the technology used in it is safe and harmless.
Conclusion
Metal detectors importance is unquestionable when it comes to security purposes. In high-security places, you might have to pass your luggage through metal detectors for scanning of weapons. So, metal detectors are essential to ensure your safety. However, it is also necessary to take alternative arrangements to check if one doesn’t feel safe walking through metal detectors.
