5. Determining uncertainty of measurement

5.1 Principle

When reporting the result of a measurement, it is necessary to give an indication (measurement uncertainty) of the quality of the result, so that those who will use it can estimate its reliability. The ideal method for evaluating and expressing the final uncertainty of the result should be :

• universal, to apply to all types of measurement ;

• to be deduced directly from the influencing factors;

• transferable, to be used in turn as a component of uncertainty.

It is also necessary to provide a confidence interval, associated with the uncertainty that will enable us to estimate that all the possibilities or probabilities of...