Non-SI units accepted for use with SI
From Freepedia
The following units are not SI units but are "accepted for use with the International System."
| Non-SI units accepted for use with SI | ||||
|---|---|---|---|---|
| Name | Symbol | Quantity | Equivalent SI unit | |
| minute | min | time | 1 min = 60 s | |
| hour | h | time | 1 h = 60 min = 3600 s | |
| day | d | time | 1 d = 24 h = 1440 min = 86400 s | |
| degree of arc | ° | angle | 1° = (π/180) rad | |
| minute of arc | ′ | angle | 1′ = (1/60)° = (π/10800) rad | |
| second of arc | ″ | angle | 1″ = (1/60)′ = (1/3600)° = (π/648000) rad | |
| litre | l or L | volume | 0.001 m3 | |
| tonne | t | mass | 1 t = 103 kg | |
| Non-SI units not formally adopted by the CGPM | ||||
| neper, field quantity | Np | ratio (dimensionless) | LF = ln(F/F0) Np | |
| neper, power quantity | Np | ratio (dimensionless) | LP = ½ ln(P/P0) Np | |
| bel, field quantity | B | ratio (dimensionless) | LF = 2 log10(F/F0) B | |
| bel, power quantity | B | ratio (dimensionless) | LP = log10(P/P0) B | |
| Non-SI units with values obtained only by experiment | ||||
| electronvolt | eV | energy | 1 eV = 1.60217733 (49) × 10−19 J | |
| atomic mass unit | u | mass | 1 u = 1.6605402 (10) × 10−27 kg | |
| astronomical unit | AU | length | 1 AU = 1.49597870691 (30) × 1011 m | |
| Non-SI units whose use is not encouraged | ||||
| nautical mile | length | 1 nautical mile = 1852 m | ||
| knot | speed | 1 knot = 1 nautical mile per hour = (1852/3600) m/s | ||
| are | a | area | 1 a = 1 dam2 = 100 m2 | |
| hectare | ha | area | 1 ha = 100 a = 10000 m2 | |
| bar | bar | pressure | 1 bar = 105 Pa | |
| ångström, angstrom | Å | length | 1 Å = 0.1 nm = 10−10 m | |
| barn | b | area | 1 b = 10−28 m2 | |
