Log on to any search engine and look for details on burglaries and you will see that an alarming number of cases are similar. Well dressed gents/ladies enter the premises of departmental stores or other commercial enterprises with a concealed weapon and then later, rob the store at gun point. And no, it’s not thugs and goons wearing masks that we are talking about over here. The criminal has evolved. Today, he/she is a part of the crowd and tries every trick in the book to ‘not’ get noticed. They wear Rolex watches, use Guess sunglasses and maybe even wear an Armani. How do you detect that the person entering your store is a criminal and has a concealed weapon on his/her body? It is extremely difficult to have armed sentinel posted at entries for small retail stores, which are more likely to be targeted. So what’s the solution?
In the last few decades, a new global threat has emerged. It’s spelled TERRORISM and it promises to make the world take guard. The problem is probably much older than we think but terrorism has seen a surge in the last few years. Radical Islamic outfits, militant organizations and small time terror groups are all coming together under one umbrella and launching extremely well etched out and coordinated attacks on governments and countries alike.
Today, no place is safe from a terror attack. Airports and government buildings are not the only places that can be targeted. Shopping malls, cinema halls, retail stores, hotels, restaurants, pubs and just about any public place can be targeted by terrorists and in such a scenario, having a security setup in place can well make a difference. Not only can you successfully prevent the terror attack from causing too many casualties but you can also successfully thwart any attempt to enter the premises with a concealed weapon in place. Not to mention the fact that even box cutters can be considered to be potential weapons.
Metal Detectors
The word metal detector can bring different pictures to the minds of different people. Some people think of the long handled device that they carried to the beach for coin shooting or for prospecting. Others think of the gadget used for relic hunting. While a majority of the people think of the security gadget used in airports and shopping malls nowadays. The metal detector was originally developed and used for mining. However, a series of hijackings forced an airline company to adopt the device to scan passengers as they walked in to enter an aircraft. This technique proved to be quite effective and even a minor metallic object was easily detected. It curbed hijackings to a large extent and metal detectors became the chosen security device for airports.
A metal detector uses one out of three different technologies to detect the presence of a metallic object.
- Very low frequency (VLF)
- Pulse induction (PI)
- Beat-frequency oscillation (BFO)
How it works
However, most of the metal detectors that we see use VLF technology. In a VLF enabled metal detector, there are two different coils (the transmitter coil and the receiver coil). When electricity passes through the transmitter coil, it creates an electromagnetic field (similar to what happens in an electric motor). The electric current keeps changing direction and each time this happens, the polarity of the magnetic field changes. When this magnetic field interacts with metallic objects, it causes them to develop weaker magnetic fields of their own. The receiver coil which is completely shielded and immune from the magnetic field of the transmitter coil picks up this magnetic field and then signals the control box that in turn analyzes the signal. Metal detectors using VLF technology relies on phase shifting to identify between different metals.
Walkthrough metal detectors
The walkthrough metal detectors which feature a wooden doorframe that we walk through uses a different technology called PI or pulse induction. A PI system has a coil of wire on one side of the arch as both the transmitter and the receiver. Short but powerful bursts of electric current are send through the coild of wire and each pulse generates a magnetic field. A normal PI based walkthrough metal detector can send about 100 pulses per second. But advanced models can send over 1000 pulses per second. These systems are multi zone (multiple transmit and receive coils at different heights) and scan each and every person for any metallic object on the body. Anything even flicked through it will be detected instantly. In the early days, these metal detectors had a high rate of false alarms as the technology could not distinguish between threat items and items used in everyday life like shoe shanks and belt buckles. But now, most walk through metal detectors has an excellent discrimination range and can easily detect ordinary metallic items on the body. Advanced models have features like a silent indicator light that will glow if a person may need to be escorted for additional security.
The walk through metal detector is ideal for use in places with a high footfall like airports and shopping malls. They have completely configurable settings that can be tailored according to the sensitivity of the place. For example, if the device is installed over metallic flooring, then the sensitivity can be adjusted accordingly. Installation and usage are extremely easy.
Hand Held Scanners
Handheld scanners are an integral part of security screening. It is a small compact handheld device that can detect the presence of any metallic object on the body of a person. It is a perfect addition to armed security personnel and lets them scan a person thoroughly without the need for touching their body. If you own a small commercial establishment and cannot afford a high end walk through metal detector, then a hand held metal detector with a security guard is the next best option. The device uses the same technology as used by high end metal detectors and features a completely flexible body with a powerful scanning head that can scan and detect the presence of a metallic object deep within the clothes. It avoids the need for security personnel to bend down or pat down unnecessarily.
The level of sensitivity is completely adjustable and can be customized to detect anything from small handguns and knives, razor blades, Needles, handcuff keys, caliber bullet and metal shanks. The handheld metal detector features a comfortable handle for better grip and works on a battery. Discreet detection is one of the most important features of the handheld security device and if a metallic object is detected, then the device vibrates and an LED light glows. This prevents patrons from getting scared or panicking. Highly compact models are also available that are ideal for low level security inspections.
Technological Advancements
A new security system has recently been tested at airports which bounces x-rays off the skin. It can completely scan through clothing without the need for human frisking. Any concealed objects on the body are shown on a monitor. However, there is still time for the new technology to be adopted on a larger scale.
