Not detected
Bounded definition
No signal was resolved above the stated method threshold.
Do not infer more: It does not mean the analyte is proven absent or exactly zero.
Wording people may use
nd, zero reading, below detection, detection limit.
Use the term in context
Continue with measurement-quality guide, nitrogen-label guide. The glossary standardizes wording; the linked guide carries the practical method, evidence and decision boundary.
Editorial definition reviewed 2026-08-12. It adds no diagnosis, universal care target or new biological evidence. Challenge this wording or provide a source.