A measurement result is usually expressed as a (“measured quantity value” ± “measurement uncertainty”).
The measured quantity value aims at estimating the “true” quantity value of a measurand (VIM3: Entry 2.10).
On the other hand, the measurement uncertainty is evaluated “based on the information used” (VIM3: Entry 2.26) since there is no “true” value for the measurement uncertainty.
The measured quantity is estimated
The measurement uncertainty is evaluated
The measurement result (e.g. “measured quantity” ± “measurement uncertainty”) is expressed.
VIM3: JCGM 200, International Vocabulary of Metrology – Basic and General Concepts and Associated Terms (VIM 3rd edition), BIPM, 2012 (https://www.bipm.org/en/publications/guides/vim.html).
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