What is Airport Security Procedures?
All public access to an airport goes via the terminal, where all objects must pass through an X-ray machine and each person must pass through a metal detector.
Pulse induction is the basis for almost all airport metal detectors (PI). A coil of wire on one side of the arch serves as the transmitter and receiver in most PI systems. With this method, the wire coil is subjected to strong, brief current bursts, or pulses. Every pulse produces a momentary magnetic field. The magnetic field abruptly collapses and changes polarity once the pulse stops, producing a strong electrical spike. Locate airport metal detector manufacturers.
For a few microseconds, or millionths of a second, the coil experiences additional current flow as a result of this spike. The reflected pulse is the name given to this following current, which lasts for only a few microseconds. The procedure then repeats with the sending of another pulse. The average pulse rate of a PI-based metal detector is around 100 per second; however, depending on the type and manufacturer, this can vary significantly, with some models sending up to 1,000 pulses per second. Get to know more about industrial safety product.
An opposing magnetic field is created in the metal object by the pulse if it goes past the metal detector. The object’s magnetic field delays the reflected pulse’s total disappearance when the pulse’s magnetic field collapses, producing the reflected pulse. This procedure functions similarly to echoes:
Screaming in a room with few hard surfaces will likely result in an extremely short echo if any at all. However, the echo lasts longer in a space with plenty of hard surfaces if you shout into it. Target item magnetic fields contribute their “echo” to the reflected pulse in a PI metal detector, extending its duration somewhat.
The metal detector’s sampling circuit is configured to track the length of the reflected pulse. The circuit can identify whether the extended decay time of the reflected pulse is due to some other magnetic field by comparing it to the predicted duration. If the reflected pulse decays more slowly than a few microseconds, it is most likely being interfered with by a metal item.
An example of the PI technology
The small, weak signals that the sampling circuit checks are sent to an apparatus known as an integrator. The signals from the sampling circuit are read by the integrator, which then amplifies and converts them to direct current (DC). The audio circuit receives the voltage from the DC and converts it into a tone that the metal detector uses to alert users when a target object has been located. You are requested to take off any metal objects from your person and reenter the area if an item is discovered. The attendant isolates the source with a portable detector built on the same PI technology if the metal detector keeps indicating the presence of metal.
A large number of the most recent metal detectors available are multi-zone. This indicates that they feature several transmit and receive coils, spaced at various heights. It functions much like several metal detectors combined into one device.