Anyone who has traveled by airplane has probably gone through a walk-through metal detector. These security devices have also been used in schools, sporting events, government offices, and concerts. They are part of a total security system that includes cameras, door access control, and emergency paging systems.
The Science Behind Metal Detectors
The metal detector utilizes the laws described by a Scottish physicist named James Clerk Maxwell (1831–1879). He discovered that magnetism and electricity are related. An example of the relationship is a coil of copper wire wrapped around a metal nail. When current is applied to the coil, the metal nail becomes magnetized.
When an electric pulse is sent through a coil of wire, it creates a magnetic field. When the field hits a metal object, it reflects back and can be detected using another coil of wire. The size and timing of the detected pulse is used to define the size and position of the object.Continue reading “How Walk-Through Metal Detectors Work”