| Accompanies | A measurement result |
|---|---|
| Evaluation | Components and measurement model |
| Is not eliminated just by | More repetitions |
Definition and context
Measurement uncertainty accompanies a result and expresses the limits of our knowledge of the measured quantity. It can include contributions from variability in observations, calibrations, resolution, and other relevant information. Its evaluation requires a measurement model.
Repeating readings does not automatically eliminate all contributions. An instrument might repeatedly produce similar values while retaining a calibration offset. This example shows why apparent precision and uncertainty cannot be resolved by counting decimal places. When reporting a result, we should explain how the uncertainty was evaluated and, where applicable, the coverage factor. It is not an admission that any value is possible: it defines what we can claim within a described procedure.
What we know and its limits
Introductory reference sheet. Properties and applications depend on measurement conditions; consult the sources before making comparisons.
Follow the evidence
The original sources for exploring this explanation and its limits.
- Technical Note 1297 · Classification of Components of Uncertainty
National Institute of Standards and Technology
Evaluation of uncertainty components using statistical methods and other information. - Technical Note 1297 · Reporting Uncertainty
National Institute of Standards and Technology
Information needed to communicate measurement results.
Image credits
Photo by Beyzaa Yurtkuran on Pexels · Original source · Pexels License