Terms and Definitions Used By The Energy Industry
Quantity

• Pico = 1/1,000,000,000,000
• Nano = 1/1,000,000,000
• Micro = 1/1,000,000
• Milli = 1/1000
• 1
• Kilo = 1000
• Mega = 1,000,000
• Giga = 1,000,000,000
• Tera = 1,000,000,000,000

• The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.
• The meter is the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second.
• The kilogram is the unit of mass; it is equal to the mass of the international prototype of the kilogram.
• The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 x 10-7 newton per meter of length. It is the SI unit of current and is represented by the letter I in formulae.
• The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water.
• The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 x 10¹² hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.
• The mole
  1. is the amount of substance of a system which contains as many elementary entities as there are atoms in 12 grams of carbon 12; its symbol is "mol."
  2. the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles

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