(See VIM, 6.1 through 6.9, and 6.13, 6.14; and NCSL pages 36–38.) A calibration standard is an IM&TE item, artifact, standard reference material, or measurement transfer standard that is designated as being used only to perform calibrations of other IM&TE items. As calibration standards are used to calibrate other IM&TE items, they are more closely controlled and characterized than the workload items they are
used for. Calibration standards generally have lower uncertainty and better resolution than general-purpose items. Designation as a
calibration standard is based on the use of the specific instrument, however, not on any other consideration. For example, in a group
of identical instruments, one might be designated as a calibration standard while the others are all general purpose IM&TE items.
Calibration standards are often called measurement standards. See also: standard (measurement)

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