The objects under examination are placed in a sealed enclosure that fills with compressed air, loosening particles of explosive materials, which can then be sensed by a conventional trace detector.

这些物体放在用压缩气体填满的封闭罩内检查，并在罩内松散易爆物颗粒，然后再由常规追踪探测器识别。

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Although that is two to three times the cost of a metal detector, it is less than the price of the fancy explosive-sniffing equipment that is the main rival technology being developed for detecting metal-free mines.

ECONOMIST: Landmines