MANUFACTURING – METROLOGY & QUALITY CONTROL CALCULATOR
Uncertainty Budget
A precise tool.
What is the Uncertainty Budget & How does it work?
In metrology, the uncertainty of a measurement quantifies the doubt about the true value. The Guide to the Expression of Uncertainty in Measurement (GUM) provides a systematic method to combine individual uncertainty components into a single combined standard uncertainty. Uncertainty components are classified as Type A (evaluated by statistical analysis of repeated observations) or Type B (evaluated by other means such as manufacturer specifications, calibration certificates, or expert judgement). Each component is expressed as a standard uncertainty, denoted (u_i), which represents a one‑sigma estimate. The combined standard uncertainty (u_c) is obtained by root‑sum‑of‑squares of the individual standard uncertainties, optionally including correlation terms. An expanded uncertainty (U) is then reported by multiplying (u_c) by a coverage factor (k) that reflects the desired confidence level.
u_c = sqrt{u_{A}^{2}+u_{res}^{2}+u_{cal}^{2}+u_{env}^{2}}
u_c = combined standard uncertainty
Parameters
Result
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Frequently Asked Questions
What is Type A uncertainty?
Type A uncertainty is evaluated by statistical analysis of repeated observations.
How do I calculate Type B uncertainty?
Type B uncertainty is evaluated using other means like manufacturer specifications or expert judgment.
What is the Guide to the Expression of Uncertainty in Measurement (GUM)?
The GUM is a systematic method for combining individual uncertainty components into a single combined standard uncertainty.
Can I use this calculator for any type of measurement?
Yes, as long as you can identify and quantify the uncertainty components for your specific measurement.
How do I interpret the final result from this calculator?
The final result is your combined standard uncertainty, which quantifies the doubt about the true value of your measurement.
What if I have more than one type of uncertainty component?
You can include all relevant components, whether Type A or Type B, and the calculator will combine them for you.
Is there a limit to the number of uncertainty components I can input?
The calculator allows you to input as many components as needed to accurately represent your measurement’s uncertainties.
Results are for informational purposes only and do not constitute professional advice.