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Explosive Vapor Detector
Explosive vapor detectors (EVD) are explosives detection instruments whose principle of operation is the selective analysis of collected vapor samples from the air, in contrast to explosives trace detectors (ETD) which require the physical collection of particulate samples from surfaces. EVDs are not limited to explosives, and may also be used to detect narcotics and other illicit or dangerous substances such as biological agents or chemical warfare agents. EVDs can be classified into two types: portable EVDs, and pre-concentrated sample EVDs. Portable units have detection limits in the ranges of parts per million or parts per billion, similar to those of ETDs or explosive detection dogs. Pre-concentrated sample EVDs have sensitivities in the range of parts per quadrillion (10−15). Principle of operation The detection process is based on two broad steps: sampling and analysis. In portable instruments, sampling and the analysis are done on the same device. Sampling A samp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosives Detection
Explosive detection is a non-destructive inspection process to determine whether a container contains explosive material. Explosive detection is commonly used at airports, ports and for border control. Detection tools Colorimetrics & automated colorimetrics The use of colorimetric test kits for explosive detection is one of the most simple methods for officers, and widely used method for the detection of explosives. Colorimetric detection of explosives involves applying a chemical reagent to an unknown material or sample and observing a color reaction. Common color reactions are known and indicate to the user if there is an explosive material present and in many cases the group of explosives from which the material is derived. The major groups of explosives are Nitroaromatic compound, nitroaromatic, nitrate ester, and Nitroamine, nitramine explosives, as well as inorganic nitrate-based explosives. Other groups include chlorates and peroxides which are not nitro based explosives. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
