People are generally familiar with explosive detectors as devices that are employed at airports, security checks and mostly by law enforcement agencies while investigating any suspicious product or baggage. However, though people are usually alien to the working mechanism of these devices, the fact is that these can be a very useful addition to the security system of our house or offices. These devices are usually based on scientific mechanism and are categorized as
1. Mechanical Scent Detectors
These devices use Ion mobility spectrometry technology, which differs from mass spectrometry in terms of the pressure that it operates at. In mass spectrometry the molecules are ionized and made to move through electric field in Vacuum. The velocity of the ionized molecule through the electric field gives a clear indication of the size of the ion and hence helps in recognition of the molecule. The IMS technology enables functioning at atmospheric pressure too. This technology is sometimes complemented with Gas chromatography which helps in obtaining better results, but at the cost of the level of ease the detector can be operated at.
2. Mass Spectrometers (MS)
This method is yet again based on Ion Mobility Spectrometry (IMS) technology and makes use of Amplifying Fluorescent Polymers (AFP) that uses molecular recognition to turn of the florescence of some particular polymer. While earlier Chemiluminiscence was frequently used, there has been an attempt to make MS technology economical for the field use by using Aerosol polymers. In this method there is no need for preparing any sample and hence it enables us to have potable explosives detectors in the field. Recently many products using similar mechanisms are under development in the United States and also in most of the developed European countries.
3. Neuron Activators
Devices using this technology usually bombard the suspected container with a stream of neuron particles and read the decay of the gamma radiations. This helps in determining the chemical composition of the material held inside the container.
4. Silicon nanowires
Silicon nanowires technology has the superior ability to detect the traces and vapors of several explosives including RDX and TNT. This is found to be the fittest technology to be incorporated in the security systems and is most feasible commercially.
5. X-Ray Machines.
X-ray machines can be specially designed to fit the purpose of detection of the explosives. These machines detect the explosive by examining the density of the scanned material. Not only the explosive material but also other parts of the bombs can be detected using these machines, unless they are hidden smartly with the help of some electrical equipment.
6. Portable devices using magnetic field
There are other portable devices available for detecting explosives in the vicinity. These devices use a self created magnetic field, and detect any change in its interaction with the earth’s magnetic field. One of the major advantages of these devices is that they can detect the explosive material from up to 100 meters distance, and hence, the user does not have to move in that close to the suspected material. Also they do not emit any radiation and hence do not put the health of the user at risk.