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Measurement · Physics · ChemistryCommon non-SI units and exact SI conversions
Common non-SI unit names require their correct SI scale factors.
DefinitionEarth & cosmos · MeasurementEarthquake location, source magnitude and local intensityA source location or magnitude does not describe the shaking experienced at every site.
DefinitionEarth & cosmos · MeasurementRight ascension, declination and reference epochsCelestial angular coordinates require a declared reference system and date conventions.
Definition