Dear
Pr33ti,
Primary Standards (
chemically and physically) are Standards with a numerous of special Qualities which must be easy to control or be controlled by special Standard Institutions.
Primary Standards for Chemistry are at least nominated by such Institutions like
NIST and
USP/EP.
NIST = National Institute of Standards and Technologies.
USP = US Pharmacopoeia;
EP = European Pharmacopoeia.
For chemical Standards and their Qualities you may read:
Low Reactivity means for Example, that these Institutions have made the selection after several assays for the most stable or the most stable modification.
Secondary Standards are Standards which are
calibrated/certified with Primary Standards.
Good Luck!
ARGOS
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