Improving Electromagnetic Shielding Ability of Plaster-Based Composites by Addition of Carbon Fibers

Table 5

Classes for professional use [42].

Grade	5, excellent	4, very good	3, good	2, moderate	1, fair
Electromagnetic effectiveness range	SE > 60 dB	60 dB ≥ SE > 50 dB	50 dB ≥ SE > 40 dB	40 dB ≥ SE > 30 dB	30 dB ≥ SE > 20 dB