of the triple-point temperature of 
on the thermodynamic Kelvin temperature scale.
is: the SI unit of temperature, one of the seven base units.
is defined: as of the triple-point temperature of on the thermodynamic Kelvin temperature scale.
is equal: to a degree Celsius 
though due to differences in the zero points of the Celsius and thermodynamic Kelvin temperature scales, the absolute temperature of an object in kelvin 
is related to its Celsius temperature 
by the formula:
[P7.2]
is never referred to: as degrees kelvin or 
but only as kelvin or K.
Copyright 1997, The Open University