The value that characterizes a quantity perfectly in the conditions that exist when that quantity is considered. It is an ideal value which could be arrived at only if all causes of measurement error were eliminated, and the entire population was sampled.
PAC, 1994, 66, 595
(Nomenclature for the presentation of results of chemical analysis (IUPAC Recommendations 1994))
on page 598
PAC, 1996, 68, 957
(Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996))
on page 996VIM
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook