The use of the security tags is the new technology method which can prevent the shoplifting in the stores and the pilferage of any book away from the libraries or the removal of the properties in the office building. The special tags can be fixed on the books or on the merchandise. Such tags are deactivated or even removed by the staff when the items have been checked out or when it is bought. On the exit, there should be a detection system that sounds the alarm or which alerts the staff when something is taken without being authorized. Some stores may put the tags on restroom so that the alarm can go off if a person takes unpaid merchandise to the restroom. If the goods are of high value and that the customers may manipulate them, the wired alarm clip can be used in the place of the tags.
There are many types of the security tags that are being used.
The magnetic system is when the tags are used to make the strip of the amorphous metal and they have a low value of the magnetic saturation. The strip has the lined strip of the ferromagnetic materials that have coercive field. The detection is done when there is the sensing of harmonic, difference or sum of the signals which have been generated by the use of the response for non-linear magnetic from the material that has been put under the mixture of the low frequency magnetic field. If ferromagnetic materials had been magnetized, it is going to give the amorphous metal strip in the saturation if it is not going to produce the harmonics. The deactivation can be done through the magnetization. The activation does need the demagnetization. The system can be suitable for books within the libraries since the system is easily deactivated if the items have been borrowed or it can be reactivated when it is returned. It can also be used in the store for the good which are of low quality because the tags are cheaper and they are of the small size.
Acousto-magnetic system is the same as the magnetic tags but it uses two different strips. The amorphous metal is used because of the high magnetoelastic coupling and it means that it can easily convert the magnetic energy in the mechanical vibrations. The tags made are thicker compared to the magnetic tags and they cannot be used easily on the books. They are cheaper and they have a good detection rate. The radio-frequency system uses the resonance peak with the LC tank circuits. The popular frequency is of 8.2 mhz. The sensing can be achieved when there is the sweeping of the resonant frequency that detects a dip. The deactivation of the label is done when a hole is made. The microwave system can be made if the non-linear element has been made and it is coupled with microwave with the electrostatic antenna. When someone reaches the exit, the antenna can emit the low frequency field while another one can emit the microwave field. The tag is going to be a mixer while emitting the combination of these signals of both fields.