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📐 Measurement Uncertainty (GUM)
Required for metrology/testing/calibration: Type A + Type B → combined uc → expanded uncertainty U (k=2)
Type A (repeat measurements, one per line; may be blank)
Type B uncertainty components (each line: name value distribution [sensitivity coeff])
Evaluation logic (GUM / JJF 1059.1)
· Type A: n repeat readings; Type A standard uncertainty uA=s/√n.
· Type B: each component u=half-width/divisor (rectangular √3, normal k=2, U-shaped √2, triangular √6); sensitivity coefficient c multiplies in directly (c·u).
· Combined: uc=√Σ(c·u)² (components assumed uncorrelated).
· Expanded: U=k·uc, k default 2 (~95% coverage probability).
· For CNAS/JJF reports, add covariance of correlated components per the actual measurement model.
About Measurement Uncertainty (GUM) Calculator
Evaluate measurement uncertainty per GUM/JJF 1059: Type A and Type B evaluation, combined standard uncertainty and expanded uncertainty.
Learn more about this tool →
Tolerance Interval
Dimensional Tolerance Judgment
Repeatability & Reproducibility (ISO 5725)
Type 1 Gage Study
Calibration Curve & Linearity
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