Other pages in this series (31)
Display constant
μ₀ · vacuum magnetic permeability
진공 투자율
Takeaway
- The relative standard uncertainty barely changed from the 2018 to the 2022 edition (1.5×10⁻¹⁰ → 1.6×10⁻¹⁰).
- The one earlier edition with a measured value has the 2022 value outside ±1σ (the error bar) and outside ±2σ (the bar doubled); the normal expectation is about 1 in 3 and 1 in 22.
- The largest move between editions came in 2018→2022, at 3.1 times the combined standard uncertainty of the two editions (|z| = 3.1).
- Measured from the 2018 edition (exact before).
- Unit
- N A⁻²
- Note
- Exact (4π×10⁻⁷) up to the 2014 edition; measured from 2018.
- M1
- —
Value ±1σ by edition2022
| Editionyear of the recommended values (data cut-off) | As printedexactly as in the source table; digits in parentheses are the standard uncertainty in the last digits | Standard uncertaintyhalf-width of the error bar (±1σ) | Relative standard uncertaintystandard uncertainty ÷ |value|: bar width relative to the value | Exactfixed by definition, uncertainty zero | z vs previous editionmove from the previous edition ÷ combined standard uncertainty of the two | z vs 2022(2022 value − this value) ÷ this edition's standard uncertainty | Source locationpage and table of the paper, or file and line of NIST's table |
|---|---|---|---|---|---|---|---|
| 1973 | 12.5663706144 e-7 | yes | 717 table 33.1 | ||||
| 1986 | 12.566370614 e-7 | yes | codata86 p.8 table 2 | ||||
| 1998 | 12.566 370 614... e-7 | yes | 1998 ASCII:181 | ||||
| 2002 | 12.566 370 614... e-7 | yes | 2002 ASCII:182 | ||||
| 2006 | 12.566 370 614... e-7 | yes | 2006 ASCII:183 | ||||
| 2010 | 12.566 370 614... e-7 | yes | 2010 ASCII:192 | ||||
| 2014 | 12.566 370 614... e-7 | yes | 2014 ASCII:192 | ||||
| 2018 | 1.256 637 062 12 e-6 | 1.9×10⁻¹⁶ | 1.5×10⁻¹⁰ | −4.4737 | 2018 ASCII:360 | ||
| 2022 | 1.256 637 061 27 e-6 | 2.0×10⁻¹⁶ | 1.6×10⁻¹⁰ | −3.0812 | 2022 ASCII:361 |