Actual performance of shielding enclosures

Two new parameters for a better understanding of the shielding performance of actual enclosures are proposed; the first parameter accounts for the overall reduction of the EM field inside (outside) the enclosure, the second concerns the uniformity of the field distribution in the protected region. The figures of merit are called global shielding efficiency and disuniformity reduction efficiency, respectively. Both stem from the mechanism of the birth of the undesired effects to be mitigated by means of the shielding enclosure.