4. Express the uncertainty of measurement of a result

4.1 Before measurement uncertainty

The emergence of measurement uncertainty (MI) follows a conceptual evolution spanning 30 years. Before MI was considered relevant, the concept of total analytical error (TAE ), introduced in 1974, was most often proposed . To define EAT, it is assumed that the deviation between the measurement and the single true value of the sample – also called total error – is made up of two parts: systematic and random. In practice, the bias is regarded as an estimate of the systematic error, and the standard deviation of precision...