Mobile metal detectors.

Mobile metal detectors.

Mobile metal detectors

The increasing number of aircraft hijackings in the late 1960s and early 1970s prompted the development of weapons detection equipment, particularly stationary metal detectors. Since then, metal detectors have evolved from simple metal detectors to sophisticated modern models equipped with «intelligence» that can distinguish non-ferrous metal from ferrous metal, weapons from personal items.

Currently, stationary metal detectors are used not only in airports, for which they were originally developed, but also in banks, offices, government buildings, museums, movie theaters, etc.

Stationary metal detectors are currently the most widely used device for mass monitoring of people for the presence of concealed weapons and other metal objects that could be used in terrorist attacks.

However, it is not always possible and advisable to use a stationary metal detector due to its design and technical parameters. So, for a single check, it is more advisable to use a hand-held metal detector. The cost of these devices is much lower than stationary ones. The range of models presented on the Russian market is quite wide, and it is always possible to choose the necessary one based on the required parameters, design and price.

At the same time, there are a number of tasks when it is necessary to control a small group of people (up to several dozen) in a short time. This may be a press conference, briefing, meeting or other event where, in order to ensure security, it is necessary to organize a temporary post to control people for weapons. The use of hand-held metal detectors is not possible due to their low productivity. The inspection time for one person is about a minute. Installation of a stationary metal detector is associated with the need to use a truck (or special) transport that ensures the transportation of long objects. The length of the side panels of a stationary metal detector is 2.1-2.5 meters. In addition, most stationary metal detectors require assembly and installation work, connection of a power supply network, etc.

In this regard, to ensure off-site events in order to organize temporary control posts, a special class of metal detectors is used — mobile metal detectors.

What are the main requirements that a mobile metal detector must meet?

• Small size and weight;
• Possibility of transportation without the use of trucks. (For example, in the trunk of a car.);
• Easy and quick installation;
• High throughput and detection parameters close to stationary metal detectors;
• Possibility of power supply from a built-in autonomous source.

One of the first mobile metal detectors — model AMD500 of the English company Adams Electronics

It consists of a dismountable control cabin (arch) and an electronic unit connected to it by a cable. To reduce weight, the cabin is made of ABS plastic. Its dimensions in the expanded form are 2020x430x930 mm. The left and right panels at the top are fastened with a crossbar, which is fixed with latches. For transportation, each panel «breaks», folds in half. Special hinge joints are provided for this. Assembly time of the product is 3 minutes.
The disadvantages of this design include insufficient vertical rigidity. To ensure greater stability, the product comes with special supports («shoes»). However, despite this, the stability of the product is not high, which does not allow it to be used, for example, outdoors, where a light wind can knock the product over.

A special bag-cover is used to transport the product. The product is powered only from a 110/220 V network.

The domestic mobile metal detector «Poisk-3S» has a similar design. The difference is that the side panel does not fold in half, but is divided into two parts, the upper and lower. When assembling, the upper panel is put on the guide pins of the lower panel and fixed in this position with screws. Two jumpers are used to fix the left and right panels in a vertical position.

The power supply for the Poisk-3S product is provided both by a 220V network and by a built-in 12V battery. Network/Battery switching is performed automatically. If the network is lost, the device operates from the battery, and if the network is available, it operates from the network.

The developers of Astrophysics (USA) took a different approach when creating the SENTRIE AT-PORTABLE model. They took the design of a stationary metal detector as a basis, with the only difference being that the side panel is not whole, but disassembled into two parts.

When installing, first assemble the left and right panels using special pads, and then assemble them in the same way as a stationary metal detector. The electronic unit has a built-in power source and is connected to the cabin using a cable.

The disadvantages of the product include its relatively large weight. The cabin weighs 40 kg, the electronic unit weighs 9.1 kg. In addition, a fairly large area is required to assemble the cabin.

The Ebinger company (Germany) used a design that is fundamentally different from stationary metal detectors. The mobile metal detector model PASSEX-100 is assembled from rectangular frames that are attached to a small bridge-type deck. The product is powered by a 220V network or a built-in 12V battery. Battery life is 15-20 hours.

A similar design is used in the domestic metal detector that is part of the Barbaris-2 technical equipment complex (developed by NPO Tekhnika of the Ministry of Internal Affairs of Russia).
An upgraded version of the PASSEX product PASSEX-100M made of lightweight aluminum tubes. This model does not have a walkway. The cabin stands on small support legs. The weight of the entire product together with the electronic unit is about 10 kg. The electronic unit is attached to the side tie. This is probably one of the lightest mobile (folding) metal detectors.

The PASSEX-100 (100M) metal detector has a built-in photo sensor that prevents the alarm from triggering if there is no person in the control zone. It is also used to count people who have passed through the metal detector.

It should be noted, however, that the presence of a photo sensor should be treated with caution. Often, the presence of a photo sensor hides the low noise immunity of the product.

The domestic mobile (folding) metal detector «Poisk-SK» was developed with the possibility of using it outdoors. It allows short-term exposure to precipitation (rain). It operates from a 220V network or a built-in 12V battery.

Structurally, it consists of four plastic panels (two lower and two upper). The lower panels have small support legs. During assembly, the upper panels are installed on the guide pins of the lower ones (similar to the Poisk-3S product). To ensure stability, additional supports can be installed in the Poisk-SK product, ensuring the rigidity of the structure. To reduce windage, the panels have round holes. The electronic unit is mounted in one of the lower panels.
A distinctive feature of the product is the absence of any cable connections. In the AMD500, Poisk-3S product, for example, a cable located in the upper crossbar and two connectors are used to connect the left and right panels. When assembling the SENTRIE AT-PORTABLE product, four cable connections are used. In addition, a connecting cable from the cabin to the electronic unit is used. In the Poisk-SK product, the necessary connections are made automatically using special contact groups during mechanical assembly of the product. This significantly reduces assembly time and eliminates errors. The product assembly time is no more than 5 minutes.

The product is controlled by a microprocessor. On the side surface of the panel there is an LCD indicator that shows the signal level, set sensitivity levels, sound signal volume, and battery charge level. The «Alarm» light board is also located here.

The product has a built-in automatic charger. When the product is powered by the mains, the battery is automatically charged (or recharged).
For transportation, the product is placed in a case measuring 1050x450x150 mm. The product weighs 16 kg.
The main weight and dimensions of some mobile metal detectors are given in the table.