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Uncertainty budget for the activity of ampoule S3-A, determined with the Vinten 671 ionization chamber (VIC) at NIST during the bilateral comparison.
| Component | ui/% |
|---|---|
| Measurement uncertainty; estimated as the relative standard deviation of the mean of N = 500 current measurements | 0.36 |
| Standard uncertainty on KVIC | 0.32 |
| Background | 0.24 |
| 228Th impurity | 0.01 |
| Decay correction | 0.001 |
| Solution composition | 0.18 |
|
| |
| Combined standard uncertainty, uc | 0.57 |
