In Bangladesh, a country where it is worth mentioning that the levels of insecurity have increased critically in recent years. Therefore, that requires the need to implement efficient technologies in which protection is ensured, or at least manages to reduce the risk of being aggrieved, due to the ignorance of the new characteristics of the technological advances of modern metal detector arches have not been implemented in environments where there is a large influx of people, for example: in schools and the Metro Collective System.
Another of the most frequent inconveniences to install them is the possibility that there are a number of false alarms when non-harmful elements such as the belt or keys are detect, which with a transport where more than 5 million people circulate, this type of security would not be efficient. This evidenced the existing ignorance about the scope of the most modern systems that have the ability to discriminate innocuous items, greatly accelerating the different processes and they do not necessarily have to be acquired by fixed purchase, but there is the possibility of leasing, which, in addition to freeing itself from the cost of assets, a huge advantage is observed by having the constant maintenance service to the arches, having the equipment always in proper operation.
It is not worth mentioning that there are several types of metal detectors for access control such as:
Archway metal detector:
Also called tunnel metal detector, detection arch, detection tunnel or metal detection head, and consists of an arch that allows to inspect all types of objects and make sure they are free of metallic or magnetic particles of any kind.
Handheld metal detector:
Police officers or security guards use it, in airports or places of special surveillance, to detect pistols and knives. They often use handheld metal detectors as a complement to non-portable metal detectors, which are arches or tunnels of detection.
Detector for the mobile phone:
It is a software or computer program that once installed in the device turns it into a metal detector, thanks to the integrated magnetic sensor. Basically, in order for it to work effectively, it requires two things: that the smartphone has a magnetic sensor and that its Operating System is compatible with the application.
All of these are useful in places such as Airports, to prevent passengers from entering weapons or bombs in the boarding area and on airplanes. In recent years they have gained importance due to the terrorist acts that have taken place.
Buildings:
such as secretaries of state, where important meetings take place, embassies, offices with great flow and handling of capital, etc., that require this type of security measures;
Prisoners:
Authorities know the fact of attempts to introduce weapons into prisons so that prisoners can protect themselves from other inmates or try to escape is well.
Massive events and sites:
Concerts, sports games, conferences, public transport, such as metro or Metro bus stations, etc., which gather a large number of people, are places where metal detectors are indispensable.
History of The First Archway Metal Detector
The beginnings of metal detectors were not good at all, it all began with the assassination attempt of American President James Garfield, who shot in Washington in 1881, before the inability to locate the bullet, Alexander Graham Bell invented a rudimentary metal detector Although in the end his life could not be saved, since the bullet was not located due to the interference of the metal of the bed where the president was, shortly after he died of the infection caused by the bullet.
Alexander Graham Bell Detector
This rudimentary metal detector was the first copy and it was this model that inspired other manufacturers. The first patent that grant to a manufacturer of metal detectors was for Gerhard Fisher in 1925, years later he began to sell the detectors commercially, and little by little they evolved, and there were other manufacturers such as Garrett or White`s later already in the 50s.
Users use metal detectors today for multiple functions in industry, security, in military work (searching for land mines among others), and as a hobby in search of metal antiques.
These are some examples of the application of metal detectors:
Today the metal detectors that are market have nothing to do with those rudimentary gadgets that were pioneers at the time. At present there are a great variety of both terrestrial and aquatic metal detectors, there are two types of detectors: pulses that are detectors that work very well in mineralized soils but have the problem that they do not discriminate against metallic trash buried in the ground., while VLFs discriminate trash better but work worse on mineralized soils. At present, the most used metal detectors are the VLF since they have a digitized screen which gives us a lot of information and they have become the preferred ones by amateurs who go out to detect in the field.
