Definitions for "Primary standard"
The primary standard is a tape that is based upon the original master standard reference tape at NIST. Its amplitude at saturation is exactly 100% UR. Secondary standard reference cards are sold by PTB in Germany; these cards may be used to calibrate magnetic stripe analyzers.
A stable, high-purity material used in titrations and other chemical analyses to prepare solutions of precisely known concentration, or to determine the concentrations of substances which react with the primary standard material. For example, NaCl is a primary standard that can be used to determine the concentration of AgNO3 in a solution by titration: NaCl(aq) + AgNO3(aq) = AgCl(s) + NaNO3(aq).
a reagent that is extremely pure, stable, has no waters of hydration, and has a high molecular weight
A term that applies to an instrument that meets conditions required for establishing the International Practical Temperature Scale.