How do walk-through metal detectors work?
Anyone who has traveled in an airplane or taken a metro train ride has probably walked through a metal detector. These days they are not only used at airports but in schools, office buildings, and public events. This is how they work:
Metal detectors utilize the laws described by a Scottish physicist named James Maxwell (1831-1879). James Clerk Maxwell is considered to be one of the most influential scientists ever. Albert Einstein acknowledged that the origins of the theory of relativity lay in Clerk Maxwell’s theories and the work of James Clerk Maxwell changed the world forever.
Maxwell’s equations define the relationship between magnetism and electricity. An example of this relationship is demonstrated by wrapping a coil of copper wire around a methyl nail. When current is applied to the coil the metal nail becomes magnetized. Maxwell’s equations also define what happens if a magnet moves over a coil of wire. In this reverse situation, the magnetic field generates a current in the wire and this is how electric generators work. Here is how this applies to the walkthrough metal detector. The walk-through metal detector has coils of wire embedded in the sides that create a magnetic field. This is referred to as pulse induction technology. A short burst of current coil pulse generates a short magnetic field. When a person walks through the metal detector, the magnetic pulse is sent into the opening. If the person is carrying a metal object, there will be a return magnetic field that will be detected by the electronics. The latest walk-through detectors provided by eSSL have multiple coils. Each of the coils creates a separate magnetic field that defines the location of the metallic object. eSSL provides metal detectors with up to 18 detection zones.
The walk-through metal detectors create large magnetic fields that cover all of the space inside the rectangular arch of the metal detector. If a person walks through the metal detector and sets off the alarm, security personnel are informed that this person could potentially be hiding a dangerous, metal-based weapon, such as a knife or a gun, and further research is conducted.
Walk-through metal detectors are just one part of a total security system. eSSL houses a variety of products and solutions that can ensure complete security of your entire facility. Visit for more information.
eSSL’s solutions are packed with quality and economical pricing which has made us more stable and reliable. With over 6 Lakh customers, eSSL has established itself as one of the leading Indian based companies and a top player in the security Industry.