All measurements made in accredited laboratories must include some consideration of the uncertainty of measurement. Today that approach has been expanded to include the uncertainty of measurement in any statement of compliance that a laboratory may make based on the measured results.

How does uncertainty affect the demonstrated compliance of a measurement?

Learn the most common approaches in making easy use of evaluated and estimated uncertainties in making conformant statements of compliance in test and calibration reports.


  • Introduction
  • How uncertainty affects a measurement to a specification.
  • The conformance area
  • Non-conformance areas
  • The “doubt zone”
  • Guard banding
  • Qualitative results
  • Changing the rules based on knowledge of the science