دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a standard recognised by an international agreement to serve as the basis for fixing the value of all other standards of the given quantity.

n: (SI) a system of units of measurement based on the metric system, adopted and described by the Eleventh General Conference on Weights and Measures. It provides an international standard of measurement to be followed when certain customary units, both US and metric, are eventually phased out of international trade operations. The symbol SI (Le Syste`me International dUnites) designates the system, which involves seven base units: (1) metre for length, (2) kilogram for mass, (3) second for time, (4) Celsius for temperature, (5) ampere for electric current, (6) candela for luminous intensity, and (7) mole for amount of substance. From these units, others are derived without introducing numerical factors.