ANNEX附則
ANNEX In the Annex, Chapter I, Section 1.1 is replaced by the following: ‘1.1. SI base units Quantity Unit Name Symbol Time second s Length metre m Mass kilogram kg Electric current ampere A Thermodynamic temperature kelvin K Amount of substance mole mol Luminous intensity candela cd Definitions of SI base units: Unit of time The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency Δ ν Cs , the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s – 1 . Unit of length The metre, symbol m, is the SI unit of length. It is defined by taking the fixed numerical value of the speed of light in vacuum c to be 299 792 458 when expressed in the unit m/s, where the second is defined in terms of Δ ν Cs . Unit of mass The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant h to be 6,626 070 15 × 10 – 34 when expressed in the unit J s, which is equal to kg m 2 s – 1 , where the metre and the second are defined in terms of c and Δ ν Cs . Unit of electric current The ampere, symbol A, is the SI unit of electric current. It is defined by taking the fixed numerical value of the elementary charge e to be 1,602 176 634 × 10 – 19 when expressed in the unit C, which is equal to A s, where the second is defined in terms of Δ ν Cs . Unit of thermodynamic temperature The kelvin, symbol K, is the SI unit of thermodynamic temperature. It is defined by taking the fixed numerical value of the Boltzmann constant k to be 1,380 649 × 10 – 23 when expressed in the unit J K – 1 , which is equal to kg m 2 s – 2 K – 1 , where the kilogram, metre and second are defined in terms of h , c and Δ ν Cs . Unit of amount of substance The mole, symbol mol, is the SI unit of amount of substance. One mole contains exactly 6,022 140 76 × 10 23 elementary entities. This number is the fixed numerical value of the Avogadro constant, N A, when expressed in the unit mol – 1 and is called the Avogadro number. The amount of substance, symbol n , of a system is a measure of the number of specified elementary entities. An elementary entity may be an atom, a molecule, an ion, an electron, any other particle or specified group of particles. Unit of luminous intensity The candela, symbol cd, is the SI unit of luminous intensity in a given direction. It is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540 × 10 12 Hz, K cd , to be 683 when expressed in the unit lm W – 1 , which is equal to cd sr W – 1 , or cd sr kg – 1 m – 2 s 3 , where the kilogram, metre and second are defined in terms of h , c and Δ ν Cs . 1.1.1. Special name and symbol of the SI derived unit of temperature for expressing Celsius temperature Quantity Unit Name Symbol Celsius temperature degree Celsius °C Celsius temperature t is defined as the difference t = T – T 0 between the two thermodynamic temperatures T and T 0 where T 0 = 273,15 K. An interval or difference of temperature may be expressed either in kelvins or in degrees Celsius. The unit “degree Celsius” is equal to the unit “kelvin”.’