Explosive vapour detectors come in different sizes, from very accurate hand-held to extraordinarily accurate industrial sized. These machines are easy to use and they give very quick feedback. They can detect minute traces of explosives on luggage, cargo or on passengers who have worked with explosives days or even weeks before. Some advanced models can detect explosive vapour on material which was in contact with explosives more than a year prior to scanning.
Some detectors can detect trace levels of explosive materials in parts per quadrillion by utilizing proprietary amplifying fluorescence polymers. The once superior detection abilities of sniffer dogs are now being rivalled by these explosive vapour detector units.
Although machines are not as good as dogs at detecting explosive vapour yet, that may change in the close future. Machines have a few advantages over dogs though, namely that dogs need to be fed, they need rest and they should get enough exercise and motivation. Machines may very well in the close future be cheaper than dogs in the long run.
Research Department explosive, 1,3,5-Trinitroperhydro-1,3,5-triazine, or otherwise known as RDX, is a compound used in a lot of explosives which release a very small amount of explosive vapour. It is more powerful than TNT. This compound usually has vapour amounts as low as parts per trillion, or even lower. Some of the most advanced vapour detection models can detect RDX at trace amounts as low as below 25 parts per quadrillion.
The other main compound which explosive vapour detectors detect is PETN, short for pentaerythritol tetranitrate ([3-Nitrooxy-2,2-bis(nitrooxymethyl)propyl] nitrate). This compound is very similar to nitro-glycerine, both of which can do a lot of damage when not detected early enough to disarm and evacuate.
With small hand-held explosive vapour detectors, people are able to look for explosives in very crammed places, such as under cars, in dustbins, quickly between luggage and other places which would otherwise not been possible to get into had the device not been so small.