Definition availableExact definition Candidate definition
Parts per million
ppmcx:ppm · Ratio
1 ppm = 0.000001 1.
- Quantity kind
- Ratio
- SI dimension
1- Allowed roles
- Scalar
- Unit system / convention
- Other conventions
- Registry code
ppm
Scope and distinctions
Ratio scale only. A concentration must additionally declare mass/mass, volume/volume, mole fraction or other appropriate basis.
Available operations
No converter is linked for this definition yet. You can inspect the definition and its sources.
Verification scope
New UUCE conversion paths have not been CVP-verified or production-attested. An exact unit definition is not a verification claim.
Candidate is a registry lifecycle state. It is not a completed review or CVP verification.
Definition sources
- BIPM — The International System of Units (SI)
9th edition, version 4.01, June 2026
Section 5.4.7: ratio quantities and ppm = 1e-6
Source checked:Definition metadata attributed to BIPM; brochure licensed CC BY 4.0.
Definition and registry versions
- Definition revision
- 1.0.0
- Registry snapshot
- 0.3.0-preview.3 · preview
- Definition lifecycle
- candidate
- Definition owner
- core.metrology
- Definition digest
1983c1456c8233b99e85c883626c8fc0ff947879b215f4ed4319e013f3b1647b- Definition dependency digest
a0c9eb8b9e3eceb6ef8230e1dd5e24da3424791639ec060bd6b75d0f3cf47b9d
Digests identify definition content; they are not CVP evidence or production attestations.