This International Standard specifies methods for the estimation of measurement uncertainty of chemical and

physicochemical methods in single laboratories based on validation data and analytical quality control results

obtained within the field of water analysis.

NOTE 1 The principles of the estimation of uncertainty specified in this International Standard are consistent with the

principles described in ISO/IEC Guide 98-3.

In this International Standard, the quantification of measurement uncertainty relies on performance

characteristics of a measurement procedure obtained from validation and the results of internal and external

quality control.

NOTE 2 The approaches specified in this International Standard are mainly based on QUAM[11], NEN 7779[8], Nordtest

TR 537[10], and Eurolab TR 1[9].

NOTE 3 This International Standard only addresses the evaluation of measurement uncertainty for results obtained

from quantitative measurement procedures. The uncertainties associated with results obtained from qualitative procedures

are not considered.