true value, \(\tau\)

in analysis
https://doi.org/10.1351/goldbook.T06527
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.
See also:
measurement result
Source:
PAC, 1994, 66, 595. (Nomenclature for the presentation of results of chemical analysis (IUPAC Recommendations 1994)) on page 598 [Terms] [Paper]