selgelt määratletud väärtus, mille alusel arvutatakse mõõtemääramatuse suhteline väärtus, clearly specified value to which reference is made in order to define the fiducial uncertainty, clearly specified value of a quantity to which the uncertainty(ies) of an instrument and/or an accessory are referred in order to specify their respective accuracies, clearly specified value to which reference is made in order to define the fiducal unceratainty, value that is used for reference is the measured value of the leakage current, value to which reference is made in order to specify the accuracy of transducer, value to which reference is made in order to specify the accuracy of the direct current resistive volt ratio box, single value for each effective range to which reference is made in order to specify the accuracy of a bridge