| 摘要 |
<p>An apparatus for detecting concealed explosive or narcotic substances using an ion mobility spectrometer (IMS) to analyze trace samples of those substances obtained by collecting adhering particles of dust from surfaces adjacent containers which may contain those concealed substances or from clothing of people that may be carrying them. The dust particles are capable, over a period of time, of adsorbing vapours emitted by concealed explosive or narcotic material in a container. Plastic explosives have very low vapour pressures but may, through mechanical abrasion and handling, distribute solid microscopic particles of that material around. The dust particles and microscopic particles can be collected by an air stream with an inertial collector and deposited onto a collecting medium, which is on a moveable surface, is then moved to another position adjacent the entrance to an ion mobility spectrometer where there are means to heat the particles to a temperature which will vaporize materials from the particles into the ion mobility spectrometer. That movable surface is provided with a number of collecting mediums for the particles so that as one is moved adjacent to the spectrometer, another collecting medium is moved beneath the base of the collector allowing collection and desorption to take place simultaneously. <IMAGE></p> |
