After the bills get fronts and backs, they undergo an inspection process — a stream of air lifts each sheet so cameras can check each side for defects.

新版纸钞在正反面完成后，必须经过严格的质检流程—利用一系列的气动升降装置，通过摄像头进行双面检验。

youdao

The technology intercepted the flow of traffic from Libya's main Internet service provider and harvested information from the stream using a method known as deep-packet inspection.

WSJ: Spy-Gear Business to Be Sold