Electromagnetic Compatibility (EMC) testing refers to the ability of a device or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment.

A shielded room blocks radio wave interference. The key parameter for measuring material penetration is permeability—higher permeability means better shielding effectiveness. The doors and windows of a shielded room significantly impact its shielding performance. There are three common types of shielded doors: