International System of Units ("SI") and prefixes

Reference

measured.si

Defines the International System of Units ("SI") and prefixes.

Attributes: Base units

Meter (Unit): The distance travelled by light in a vacuum in 1/299792458 seconds.

Second (Unit): The duration of 9192631770 periods of the radiation corresponding to
    the transition between the two hyperfine levels of the ground state of the
    caesium-133 atom.

Gram (Unit): The kilogram is defined by setting the Planck constant _h_ exactly
    to 6.62607015×10⁻³⁴ J⋅s (J = kg⋅m²⋅s⁻²), given the definitions of the metre and
    the second.  Note that `measured` uses `Gram` as the base unit for SI, for
    simplicity with manipulating metric prefixes.  It also defines a separate
    `Kilogram` with a conversion to `Gram`.

Ampere (Unit): The flow of exactly 1/1.602176634×10⁻¹⁹ times the elementary charge
    _e_ per second.  Internally, `measured` uses `Coulomb` as a base SI unit, and
    derives `Ampere` from it.

Kelvin (Unit): The kelvin is defined by setting the fixed numerical value of the
    Boltzmann constant _k_ to 1.380649×10⁻²3 J⋅K⁻¹, (J = kg⋅m²⋅s⁻²), given the
    definition of the kilogram, the metre, and the second.

Mole (Unit): The amount of substance of exactly 6.02214076×10²³ elementary entities.

Candela (Unit): The luminous intensity, in a given direction, of a source that emits
    monochromatic radiation of frequency 5.4×10¹⁴ hertz and that has a radiant
    intensity in that direction of 1/683 watt per steradian.

Attributes: Derived units

Hertz (Unit): measures `Frequency`

Radian (Unit): measures `PlaneAngle`, a dimensionless `Number`

Steradian (Unit): measures `SolidAngle`, a dimensionless `Number`

Newton (Unit): measures `Force`

Joule (Unit): measures `Energy`

Watt (Unit): measures `Power`

Coulomb (Unit): measures `Charge`.  Internally, `measured` uses `Coulomb` as a base
    SI unit, and derives `Ampere` from it.

Volt (Unit): measures `Potential`

Farad (Unit): measures `Capacitance`

Ohm (Unit): measures `Resistance`

Siemens (Unit): measures `Conductance`

Henry (Unit): measures `Inductance`

Weber (Unit): measures `MagneticFlux`

Tesla (Unit): measures `MagneticBField`

Lumen (Unit): measures `LuminousFlux`

Lux (Unit): measures `Illuminance`

Becquerel (Unit): Radioactive decays per unit time (alias for `Hertz`)

Gray (Unit): absorbed dose of ionizing radiation (measures `RadioactiveDose`)

Sievert (Unit): equivalent dose of ionizing radiation (measures `RadioactiveDose`)

Katal (Unit): measures `Catalysis`

Attributes: Prefixes (base 10)

Yotta (Prefix): 10 ²⁴, symbol `Y`

Zetta (Prefix): 10²¹, symbol `Z`

Exa (Prefix): 10¹⁸, symbol `E`

Peta (Prefix): 10¹⁵, symbol `P`

Tera (Prefix): 10¹², symbol `T`

Giga (Prefix): 10⁹, symbol `G`

Mega (Prefix): 10⁶, symbol `M`

Kilo (Prefix): 10³, symbol `k`

Hecto (Prefix): 10 ², symbol `h`

Deca (Prefix): 10¹, symbol `d`

Deci (Prefix): 10⁻¹, symbol `d`

Centi (Prefix): 10⁻², symbol `c`

Milli (Prefix): 10⁻³, symbol `m`

Micro (Prefix): 10⁻⁶, symbol `μ`

Nano (Prefix): 10⁻⁹, symbol `n`

Pico (Prefix): 10⁻¹², symbol `p`

Femto (Prefix): 10⁻¹⁵, symbol `f`

Atto (Prefix): 10⁻¹⁸, symbol `a`

Zepto (Prefix): 10⁻²¹, symbol `z`

Yocto (Prefix): 10⁻²⁴, symbol `y`