Table I.
Cascade Impactor Configurations and Stage Effective Cutoff Diameters
| Impactor system | Component | ECD at 60 L/min (μm) | Stage groupings |
|---|---|---|---|
| NGI | Induction port | N.D. | LPM>4.46 μm |
| Preseparatora | 12.7 | ||
| Stage 1 | 8.06 | ||
| Stage 2 | 4.46 | ||
| Stage 3 | 2.82 | FPM0.94–4.46 μm | |
| Stage 4 | 1.66 | ||
| Stage 5 | 0.94 | ||
| Stage 6 | 0.55 | EPM<0.94 μm | |
| Stage 7 | 0.34 | ||
| ACI | Induction port | N.D. | LPM>6.18 μm |
| Preseparatorb | N.D. | ||
| Stage 0b | 6.18 | ||
| Stage 1 | 3.99 | FPM0.76–6.18 μm | |
| Stage 2 | 3.22 | ||
| Stage 3 | 2.77 | ||
| Stage 4 | 1.44 | ||
| Stage 5 | 0.76 | EPM<0.76 μm | |
| Stage 6 | 0.48 | ||
| Stage 7 | 0.27 |
N.D. effective cutoff diameters (ECD) not defined
aAPI assayed treating NGI preseparator as a separate stage
bMass on stage 0 added to mass in preseparator