Table 2.
Quantitative measurement of exposure dose in mW/cm2 at 5 locations on convex (A) and concave (B) surface of the FFR, as demonstrated in Figure 3
| Mask height | Rack column | Position on mask | Irradiance (mW/cm2) | Irradiance normalized to position 3A | Time (sec) to deliver 1000 (mJ/cm2) |
|---|---|---|---|---|---|
| 68.5 (cm) | 1 | 1A | 1.868 | 1.24 | 535 |
| 2A | 0.637 | 0.42 | 1570 | ||
| 3A | 1.501 | 1.00 | 666 | ||
| 4A | 0.745 | 0.50 | 1343 | ||
| 5A | 0.746 | 0.50 | 1340 | ||
| 1B | 1.212 | 0.81 | 825 | ||
| 2B | 1.129 | 0.75 | 886 | ||
| 3B | 1.205 | 0.80 | 830 | ||
| 4B | 1.396 | 0.93 | 716 | ||
| 5B | 1.574 | 1.05 | 635 | ||
| 162.0 (cm) | 3 | 1A | 1.150 | 0.72 | 870 |
| 2A | 0.966 | 0.61 | 1036 | ||
| 3A | 1.596 | 1.00 | 627 | ||
| 4A | 0.775 | 0.49 | 1290 | ||
| 5A | 1.684 | 1.06 | 594 | ||
| 1B | 1.505 | 0.94 | 664 | ||
| 2B | 1.126 | 0.71 | 888 | ||
| 3B | 1.342 | 0.84 | 745 | ||
| 4B | 1.241 | 0.78 | 806 | ||
| 5B | 0.675 | 0.42 | 1481 |
Abbreviation: FFR = filtering facepiece respirator.
Measurements obtained via ultraviolet germicidal irradiation meter. The most divergent locations were selected as examples of dose distribution across the FFR. Substantial variation in dose is demonstrated and dependent on distance from bulb, proximity to aluminum flashing, and arced surface of FFR. The irradiance at each position is normalized to position 3A (bold). Additional measurements from other rack locations are demonstrated in Table E1.