Outside-In He Leak Measurements in One Laboratory
| Type of Artificially Created Leak | Nominal Size | N | n | Avg | Min | Max | Span |
|---|---|---|---|---|---|---|---|
| Fused silica capillary in viala | 10 µm× 11 mmb | 1 | 30 | 6.7E-05 | 6.2E-05 | 7.3E-05 | 0.07 |
| Fused silica capillary in viala | 10 µm× 12 mmb | 100 | 1 | 7.3E-05 | 6.4E-05 | 8.1E-05 | 0.10 |
| Laser-drilled hole in steel tubing in vial | 5 µm (FED) | 35 | 1 | 8.2E-04 | 3.5E-04 | 1.1E-03 | 0.50 |
| Laser-drilled hole in steel tubing in vial | 10 µm (FED) | 35 | 1 | 3.3E-03 | 2.6E-03 | 3.9E-03 | 0.18 |
| Laser-drilled hole in steel tubing in vial | 20 µm (FED) | 35 | 1 | 1.6E-02 | 1.4E-02 | 1.8E-02 | 0.11 |
Notes: FED = flow effective diameter based on air flow measurements (differences up to 20% were reported between certified flow rates). N = Number of prepared units. n = Number of replicate measurements per unit.
↵a Capillary was glued into rubber stopper of a vial.
↵b Nominal internal diameter x length of capillary.