Measurement Uncertainty
Measurement uncertainty is a quantified expression of the doubt associated with a measurement result.
What this term means in maintenance
Measurement uncertainty is a quantified expression of the doubt associated with a measurement result.
Why measurement uncertainty matters
Every measurement has limits. Uncertainty helps users understand the range within which the true value is reasonably expected to lie.
Sources of uncertainty
Possible contributors include:
- Reference standard
- Instrument resolution
- Repeatability
- Environmental conditions
- Method
- Operator
- Fixture
- Calibration process
- Data analysis
Practical example
A calibration result is reported as 100.0 °C with an expanded uncertainty of ±0.2 °C. The uncertainty must be considered when deciding whether the instrument meets a tight tolerance.
Uncertainty and acceptance
Organizations should define decision rules for results close to the tolerance limit.
Calibration certificates
Accredited calibration certificates commonly report measurement uncertainty and traceability information.
Common mistake
Treating the displayed reading as exact can lead to incorrect pass-or-fail decisions near specification limits.
Related concepts
Related maintenance terms
Keep exploring connected CMMS, reliability, and maintenance planning terms.
Calibration Certificate
A calibration certificate is the formal record of an instrument’s calibration results, reference standards, measurement uncertainty, traceability, and acceptance status.
Verification
Verification is the confirmation, using objective evidence, that specified requirements have been fulfilled.
Calibration
Calibration is the documented comparison of a measuring instrument against a known reference to determine its accuracy and confirm whether it remains suitable for use.
Glossary FAQs
- What is measurement uncertainty?
It is a quantified expression of the doubt associated with a measurement result.
- Why does uncertainty matter near a tolerance limit?
It affects confidence in whether the result truly meets the requirement.
- Where is uncertainty normally reported?
It is commonly reported on calibration certificates and measurement reports.