4. Assessing the uncertainty of analytical results
4.1 Concept of uncertainty
The purpose of a measurement is to assign a value to the measurand, the measurand in the vocabulary of metrology being the quantity we seek to measure.
The hazards of any measurement process lead us to "estimate" the measurands and assign them the value in which we are most confident. Our "measurement result" variable can therefore be likened to a random variable whose distribution can be summarized by two parameters: a central tendency parameter, which is estimated by the mathematical expectation of the distribution, i.e. the value we announce, and a dispersion parameter, the standard deviation of the distribution, also known as the standard uncertainty.
If we accept this, then the definition of uncertainty...
The Ultimate Scientific and Technical Reference
This article is included in
Laboratory quality and safety procedures
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
Assessing the uncertainty of analytical results
Use of internal laboratory data
Bibliography
References
Standardization
The catalog of the Association française de normalisation (Afnor) can be consulted online: http://www.afnor.fr
XP T90-210 12-99 Water quality – Protocol for evaluating an alternative method of quantitative physico-chemical analysis in relation to a reference method
FD V01-000 12-99 Analysis of agricultural...
Organizations
French national metrology and testing laboratory (LNE)
French Environment and Energy Management Agency (Ademe)
United Kingdom Accreditation Service (UKAS) (formerly National Measurement Accreditation...
The Ultimate Scientific and Technical Reference
