Blank indications and null measurement uncertainty
A zero or blank reading can still have uncertainty.
Key knowledge
A blank indication is obtained for a phenomenon, body or substance similar to the investigated one but with the quantity of interest assumed absent or not contributing. Null measurement uncertainty is associated with a null or near-zero measured quantity value. Neither a blank nor a null indication guarantees zero uncertainty; subtracting a blank requires the measurement model and the uncertainties and any covariance of the sample and blank results.
Conditions and scope
- The blank must be appropriate to the procedure and matrix; its absent-contribution assumption needs support.
- Blank subtraction is not universally required and does not automatically remove all interference or systematic effects.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
- International Vocabulary of Metrology (VIM3)Joint Committee for Guides in Metrology (JCGM)Reference guideVIM3, entry 4.2VIM3, entry 4.29
Evidence and review
Read VIM4.2 blank-indication definition and4.29 null-measurement-uncertainty definition/notes. The subtraction/covariance qualification is a stated reuse of the existing measurement-model covariance result, not a newly asserted blank correction method.
2026-10-10 · /root/audit_life_earth_chemistry — independent Chemistry/Life/Earth editor. Independent AI editorial review of this entry's statements, equations, applicability conditions and source coverage. Source checks apply to these claims within their stated limits.
Entry details
Permanent link to this entry ↗- Record identity
- foundation-measurement-blank-null-uncertainty
- Revision
- foundations-refresh.1
- Structured reference record
- Foundational reference additions