Applies to the specification of performance, with primary reference to industrial applications, of the following kinds of electrical and electronic equipment: - indicating and recording instruments which measure electrical quantities; - material measures which supply electrical quantities; - instruments which measure non-electrical quantities using electrical means, for all parts of the measuring chain which present electrical output signals. It is based on the methods expounded in GUM for expressing and evaluating the uncertainty of measurement, and refers to GUM for the statistical procedures to be used in determining the intervals assigned to represent uncertainty (including the way to account for non-negligible uncertainties in the traceability chain). The object is to provide methods for ensuring uniformity in the specification and determination of uncertainties of equipment within its scope. All other necessary requirements have been reserved for dependent IEC product standards pertaining to particular types of equipment which fall within the scope of this standard.