Table 4 Characteristics of the mask type tested in the preliminary tuning tests (mask ID: A) and in the comparative BFE measurements (mask ID: B, C, D).
Mask ID | Mask type | Filter material | No. of filter layers | Structure of filter layers | Filter area (cm2) | Mask image |
|---|---|---|---|---|---|---|
A | Surgical type II R | PP | 3 | S, M, S | 195 |
|
B | Community | PP | 1 | S | 361 |
|
C | Surgical type I | PP | 3 | S, S, S | 201 |
|
D | Surgical type II | PP | 3 | S, M, S | 187 |
|
