Concepts of measurand, characteristic, and test result
Assessment of uncertainty in analytical results

It may seem trivial to say that defining what one wants to measure—that is, defining the measurand—is the first step an analyst must take. The term “measurand,” which comes from the field of metrology, is not yet in common use among chemists. The concept is, however, important and deserves closer attention. The document JCGM 200, “International Vocabulary of Metrology–: Fundamental and General Concepts and Associated Terms (VIM),” defines the measurand as “the quantity that is to be measured.”