Metal detectors are used to find metal objects on persons or in packages. Coils within a metal detector create a small electromagnetic field that reverberates against metal objects. When the coils reverberate from the metal, a computer or microprocessor alerts the security personnel that there is metal on the person or in a package. The most common metal detector is the walk-through type, which is often seen at airports or government buildings.
Privacy Concerns vs. Public Safety
A main concern for all metal detectors anywhere is privacy. For the system to be effective, security or government guards have to inspect some of the people who pass through the detector to see if they have any dangerous or prohibited objects on their person. In the tradition of civil liberties and privacy, many people have become uncomfortable by increased metal detection. However, proponents of walk-through detectors argue that metal detectors increase public safety both by deterring the carrying of weapons and by finding the weapons that people do try to carry through.
In the contemporary medical age, there may be a number of legitimate medical reasons that a person has metal on his body. If the person sustained bodily injury and required a metal device to be surgically installed within his body, the metal detector might go off, subjecting the person to increased scrutiny. However, since security personnel monitor computers that create images of metal objects sensed by the metal detector, the security personnel can see that the metal object may be a harmless tool and not a weapon.
The electromagnetic field that a metal detector creates can be relatively small. However, the size of walk-through metal detectors usually creates large electromagnetic fields. This may cause electrical interference to any number of electronic devices within the vicinity, including medical devices. Most importantly, the electromagnetic field may be strong enough to harm pacemakers.
The main purpose of a metal detector is to curb violence. Some people worry about the use of metal detectors in schools, while others support detectors for their ability to remove weapons from public spaces. However, even if studies show a reduction in school or public building violence from walk-through metal detectors exclusively, there can be any number of methodological issues with any specific study. Also, the further application of metal detectors in public spaces will most likely increase public dialogue over privacy.