CIRP Encyclopedia of Production Engineering

2014 Edition
| Editors: The International Academy for Production Engineering, Luc Laperrière, Gunther Reinhart


  • Wolfgang Knapp
Reference work entry



Closeness of agreement between a measured quantity value and a true quantity value of a measurand
  • NOTE 1 The concept “measurement accuracy” is not a quantity and is not given a numerical quantity value. A measurement is said to be more accurate when it offers a smaller measurement error.

  • NOTE 2 The term “measurement accuracy” should not be used for measurement trueness, and the term measurement precision should not be used for “measurement accuracy,” which, however, is related to both these concepts.

  • NOTE 3 “Measurement accuracy” is sometimes understood as closeness of agreement between measured quantity values that are being attributed to the measurand.

(ISO/IEC Guide 99 2007, Definition 2.13)

Theory and Application

Let us start with the definition of accuracy as given in (ISO/IEC Guide 99 2007), the International Vocabulary of Metrology (VIM), see “Definition.”

From this definition we have to conclude that the term...

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  1. ISO 230–2 (2006) Test code for machine tools – part 2: determination of accuracy and repeatability of positioning numerically controlled axes. ISO, GenevaGoogle Scholar
  2. ISO 5725 (1994–2005) Accuracy (trueness and precision) of measurement methods and results, part 1–6. ISO, GenevaGoogle Scholar
  3. ISO 10360 (2000–2011) Geometrical product specifications (GPS): acceptance and reverification tests for coordinate measuring machines (CMM), part 1–7. ISO, GenevaGoogle Scholar
  4. ISO/IEC Guide 99 (2007) International vocabulary of metrology: basic and general concepts and associated terms (VIM). ISO, GenevaGoogle Scholar

Copyright information

© CIRP 2014

Authors and Affiliations

  1. 1.IWF, ETH Zurich, Head MetrologySchleitheimSwitzerland