Work out gauge r and r instantly with clear inputs, formula shown and shareable results.
Gauge repeatability and reproducibility combines equipment variation and appraiser variation in quadrature. Expressed against total study variation or against tolerance, under 10% is acceptable, 10-30% is marginal and above 30% means the measurement system cannot be trusted to make the decision it is being used for.
Combined GRR
GRR = sqrt(repeatability^2 + reproducibility^2)
Ratios
%Study = GRR / total variation x 100; %Tolerance = 6 x GRR / tolerance x 100; ndc = 1.41 x PV / GRR
Against tolerance when the gauge is used to accept or reject parts, and against study variation when it is used for process improvement and capability work. They can give very different verdicts.
How many separate levels of part size the gauge can reliably distinguish. Fewer than five makes the gauge unusable for variables control charting.