Table 1.
Relative standard uncertainties in the measurement of the 10 pF bank with the calculable capacitor. The last row is the root-sum-square (rss) of the uncertainties listed in the rows above.
| Source of uncertainty | Relative standard uncertainty (i.e., estimated relative standard deviation) |
|---|---|
| Type A standard uncertainties | |
|
| |
| Variability of repeated observations | 2 × 10−9 |
|
| |
| Type B standard uncertainties | |
|
| |
| Geometrical imperfections in the calculable capacitor | 15 × 10−9 |
| Laser and interferometer alignment | 3 × 10−9 |
| Frequency (loading) corrections | 4 × 10−9 |
| Microphonic coupling | 5 × 10−9 |
| Voltage dependence | 5 × 10−9 |
| Transformer ratio measurement | 2 × 10−9 |
| Bridge linearity and phase adjustment | 3 × 10−9 |
| Detector uncertainties | 2 × 10−9 |
| Drift between calibrations and failure to close | 6 × 10−9 |
| Coaxial choke effectiveness | 1 × 10−9 |
| Temperature corrections for 10 pF capacitors | 2 × 10−9 |
| Relative standard uncertainty (rss) | 19 × 10−9 |