Appendices: Definitions

Reading time
  • Repeatability : dispersion obtained by the same operator, on the same part, using the same instrument. Instrument-specific error.
  • Reproducibility : variation resulting from a change in operator.
  • GRR : When combined, the total error of the measurement system.
  • Cpc : control process capability; the relationship between the tolerance and the dispersion of the measurement mean. The equivalent of Cp, as applied to measurement.
  • ndc : the number of distinct categories that the instrument can distinguish in the actual output.
  • Cg, Cgk : Capabilities of the measuring instrument on a calibrated test piece, first without and then with the offset taken into account.
  • Inertia : a combination of accuracy and repeatability into a single indicator.
  • Kappa : agreement among judges, adjusted for chance.