Table 2.
Scores for collection filters.
| Collection filter score from 1 (low) to 5 (high) |
||||||||
|---|---|---|---|---|---|---|---|---|
| MCE (3 µm) Flow rate, L min−1 |
PTFE (1 µm) Flow rate, L min−1 |
PTFE (3 µm) Flow rate, L min−1 |
PC (3 µm) Flow rate, L min−1 |
|||||
| Characteristic | 2 | 4 | 2 | 4 | 2 | 4 | 2 | 4 |
| Pressure drop @ low RH | 5.0 | 5.0 | 5.0 | 4.0 | 5.0 | 5.0 | 5.0 | 5.0 |
| Pressure drop @ high RH | broken | 5.0 | 4.0 | 5.0 | 5.0 | 5.0 | 5.0 | |
| Physical integrity of the filter at high RH | 1.0 | 1.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 |
| Physical collection efficiency in the Bt(k) size range | 5.0 | 5.0 | 5.0 | 5.0 | 4.5 | 4.0 | 4.5 | 4.0 |
| Extraction efficiency | 4.0 | 4.0 | 4.5 | 4.5 | 5.0 | 5.0 | 5.0 | 5.0 |
| Capability of shortening the ultrasonication time | 5.0 | 5.0 | 5.0 | 5.0 | 4.0 | 4.0 | 5.0 | 5.0 |
| Consistency at different sampling times = 0–8 hr | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 |
| Total recovery variability (CV) | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 |
| User-friendliness of the filter manipulation | 4.0 | 4.0 | 5.0 | 5.0 | 4.0 | 4.0 | 3.5 | 3.5 |
| Consistency of performance in the presence of dust | 5.0 | 5.0 | 3.0 | 3.0 | 5.0 | 5.0 | 4.5 | 4.5 |
| Cost and availability | 4.5 | 4.5 | 2.5 | 2.5 | 3.0 | 3.0 | 5.0 | 5.0 |
| TOTAL per flow rate | 42.5 | 42.5 | 49 | 47 | 49.5 | 49 | 51.5 | 51 |
| TOTAL average score for two flow rates | 42.5 | 48 | 49.25 | 51.25 | ||||