Vapour and trace detection of explosives

Vapour detection and trace detection of explosives are the two basic methods of explosive detection. The boundary conditions in vapour detection and trace detection are discussed. The main advantage of vapour detection is a quick and operational easy search of objects, persons and buildings by hand-held detectors. The substantial problem is the temperature dependence of explosive vapour pressure. The limits of vapour detection at low temperature are demonstrated and discussed. The further increase of sensitivity of detectors and improvement of preconcentrator capacity is required. The trace or particle detection is not so quick and operational suitable but this method is independent on temperature conditions. Usually, one particle found and inserted in a detector inlet is sufficient for positive detection. The synergy of simultaneous use of vapour and trace detection can substantially increase the effectiveness of explosive detection. The marking of plastic explosives for detection and improving of vapour detection is discussed.