NOTE 1 A calibration diagram is the strip of the plane defined by the axis of the indication and the axis of measurement result, that represents the relation between an indication and a set of measured quantity values. A one-to-many relation is given, and the width of the strip for a given indication provides the instrumental measurement uncertainty.

NOTE 2 Alternative expressions of the relation include a calibration curve and associated measurement uncertainty, a calibration table, or a set of functions.

NOTE 3 This concept pertains to a calibration when the instrumental measurement uncertainty is large in comparison with the measurement uncertainties associated with the quantity values of measurement standards.