a (rfc-def) A
metric scale of
temperature, originally defined as having the
freezing point of water as 0° and its
boiling point as 100°, at standard atmospheric pressure. The standardized definition has 0.01° C as the
triple point of water, and a difference in temperature of 1° C corresponds to 1/273.16 of the difference in temperature between the triple point and the
absolute zero.