Open Access
Review
Table 2
Impact of new definitions of the SI base units.
| Unit | Constant used as reference | Symbol | Actual definition | Proposed definition |
|---|---|---|---|---|
| kg | Mass of prototype kilogram | m (K) | Exact | 1.0 × 10−8 |
| Planck constant | h | 5.0 × 10−8 | Exact | |
| A | Vacuum magnetic permeability | µ 0 | Exact | 2.3 × 10−10 |
| Elementary charge | e | 2.5 × 10−8 | Exact | |
| K | Temperature of triple point of water | T TPW | Exact | 3.7 × 10−7 |
| Boltzmann constant | k B | 1.7 × 10−6 | Exact | |
| mol | Molar mass of 12C | M (12C) | Exact | 4.5 × 10−10 |
| Avogadro number | N A | 1.4 × 10−9 | Exact |
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