Measurement Uncertainty
Embed This Widget
Add the script tag and a data attribute to embed this widget.
Embed via iframe for maximum compatibility.
<iframe src="https://unitfyi.com/iframe/glossary/uncertainty-def/" width="420" height="400" frameborder="0" style="border:0;border-radius:10px;max-width:100%" loading="lazy"></iframe>Paste this URL in WordPress, Medium, or any oEmbed-compatible platform.
https://unitfyi.com/glossary/uncertainty-def/Add a dynamic SVG badge to your README or docs.
[](https://unitfyi.com/glossary/uncertainty-def/)Use the native HTML custom element.
Definition
A parameter, associated with a measurement result, that characterizes the dispersion of values reasonably attributable to the measurand, expressed as a standard uncertainty or expanded uncertainty.
Explanation
A mass measurement of 100.35 g with an expanded uncertainty of ±0.05 g (coverage factor k=2, 95% confidence) means the true mass lies between 100.30 g and 100.40 g with 95% probability. Uncertainty has two components: Type A (statistical analysis of repeated readings) and Type B (from calibration certificates, specifications, and physical reasoning). GUM (Guide to the Expression of Uncertainty in Measurement) is the international standard for uncertainty calculation.
RELATED ARTICLES
From milligrams to metric tons, this guide covers every major weight and mass unit with exact conversion factors, real-world examples, and a clear explanation of why weight and mass are not the same thing.
Complete Guide to Length Units: From Nanometers to Light-YearsA comprehensive reference covering every major length unit—metric, imperial, nautical, and astronomical—with exact conversion factors and real-world scale examples.
RELATED TERMS
Conversion Factor
A numerical multiplier used to convert a quantity from one unit to another.
Precision
The degree of refinement in a measurement, indicated by the number of significant digits.
Accuracy
How close a measurement is to the true value of the quantity being measured.
Dimensional Analysis
A method of converting units by multiplying by conversion factors that equal 1.
Nautical Mile
A unit of distance used in sea and air navigation, equal to 1,852 meters.