The 'Naji Plot', a simple graphical tool for the evaluation of inter-laboratory comparisons

摘要

A simple graphical method is presented allowing a summary overview of the results submitted to inter-laboratory comparisons, for which an independently determined reference value is available. This graphical method displays z scores on the horizontal axis and relative uncertainties (u_(lab)/u_(ref)) on the vertical axis, making it possible to simultaneously compare the laboratory values to the reference value, and laboratory uncertainties to the reference uncertainty. Several examples are presented.