Uncertainty relations validation procedures

From an analytical point of view, the general lack of suitable CRMs is a standing problem for the effective development of analytical measurements, as it does not favour elemental analysis at the development, production and control level. To improve the accuracy and precision of the currently used analytical measmement protocols CRMs are an ideal tool. In the total validation procedure they fulfil an important role. The ultimate performance test for any calibrated analytical instrument is to analyse a CRM and obtain a result within the expected uncertainty range. Actually, if a matrix CRM is subjected to the whole analytical process then this serves to validate the entire procedure, thus saving much time and effort. More often than not, however, in R D no CRM is available at all and it is not possible to relate a property to an existing (inter)national standard. In... 

Traceability of a result is related to traceability of a method, which in turn is linked to traceability of standards and traceability of the equipment used in the analytical procedure (Figure 3). A method is called traceable when it produces results (with their uncertainties) which are characterized by a defined traceability to well-stated references [24]. Walsh [25] defines traceable methods as validated official or standard methods or validated methods which contain uncertainty state-... 

For nonstandard methods, the standard 17025 lists 11 items required for the procedure. Methods must be validated (see chapter 7) and measurement uncertainty estimated (see chapter 6). In subsection 5.4, reference is made to the control of data, particularly in relation to electronic or automated equipment. 

A reference material certificate is defined by ISO 31 2000—Guide to the Contents of Certificates and Label of Reference Materials—diS a document accompanying a certified reference material stating one or more property values and their uncertainties, and confirming that the necessary procedures have been carried out to ensure their validity and traceability . For example, this would include information relating to the batch number, a description of the material, the concentration of the material, storage conditions, and expiry date. The content of the certificate is discussed in detail in ISO 31 2000— Guide to the Contents of Certificates and Label of Reference Materials. 

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