During work, host computer, display, printer, duplicating machine, facsimile apparatus and so on will unavoidably produce electromagnetic radiation that contains in-process data information.

• 计算机主机、显示器、打印机、复印机和传真机等在工作时不可避免地会产生电磁波辐射，这些辐射中携带有正在进行处理的数据信息。