IJCA Vol 5 Issue 1 - Flipbook - Page 34
The International Journal of Conformity Assessment
remain within permissible bounds over time rather
than only at the time of calibration.
Practical guidance extends these elements to
include maximum permissible error/limits for
application, the comparison method, and the
expanded uncertainty of the comparison itself.
Because measurements ultimately express
quantities in the International System of Units (SI),
traceability also demands a clear realization of SI
units at the top of the chain and consistent unit
handling all the way down.
To ensure greater stability, universality, and
to improve measurements, without changing
the actual size of the units themselves, the
International System of Units (SI) was redefined
by no longer relying on physical artifacts
defining all seven base units (second, meter,
kilogram, ampere, kelvin, mole, candela) by fixed,
fundamental physical constants, like the speed of
light for length and Planck's constant for mass,
effective May 20, 2019.
Another indispensable document for laboratory
accreditation is ILAC-P10:07/2020 describing
metrological traceability and providing consistent
worldwide application.
Differences between national traceability
documents and ILAC P10:07/2020
• Compared with ILAC P10, the International
Vocabulary of Metrology (VIM, JCGM 200)
is primarily terminological and conceptual: it
defines metrological traceability as a property
of a measurement result and introduces related
concepts (e.g., traceability chain), but it does not
prescribe acceptable traceability routes or the
evidence an accreditation body should require.
• ISO/IEC 17025:2017 (Clause 6.5) elevates
traceability to a competence requirement, yet it
remains deliberately high-level about the practical
hierarchy. ILAC P10 therefore acts as the
operational bridge: it converts the concept into
an accreditation policy by detailing acceptable
routes (e.g., CIPM MRA-linked NMIs and ILAC
MRA-accredited calibration laboratories),
clarifying how uncertainty and capabilities are
evaluated for fitness-for-purpose, and updating
expectations for metrological traceability
achieved through reference materials in line with
developments in ISO 17034 accreditation of
reference material producers.
National accreditation-body documents often
adopt ILAC P10 as the technical baseline but
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2026 | Volume 5, Issue 1
diverge by adding economy-specific governance
and assessment mechanics. For example, NIST’s
policy and FAQ (Frequently Asked Questions) are
not an accreditation policy; they focus on how
NIST measurement services support traceability
claims and caution against the informal label
“NIST-traceable,” a provider-centric scope
that is narrower than ILAC P10’s harmonized
accreditation intent. In contrast, UKAS TPS 41,
IAS/TL/025, NATA’s metrological traceability
policy, Cofrac GEN REF 10, CLAS requirements,
and similar AB policies largely mirror ILAC P10’s
routing logic, yet expand the practical “how”
of demonstrating conformity: they specify
certificate contents and review checks (e.g.,
stated uncertainty, reference standards, scope/
CMC match), introduce additional expectations
for calibration intervals and intermediate checks,
and may explicitly couple traceability control with
measurement uncertainty governance for testing
laboratories.
Several policies extend beyond ILAC P10’s generic,
cross-economy framing by embedding traceability
within national legal-metrology architectures or
sector-specific guidance. Armenia’s ARMNAB
policy makes traceability elements explicit and
defines internal calibration as a controlled activity
that cannot be marketed as an accredited service,
while Romania’s RENAR P-05 tightens national
context via Romanian-language controls and links
to national metrology infrastructure. Russia’s
Rosaccreditation traceability policy, together with
the measurement-uniformity framework in Federal
Law No. 102-FZ and the national recommendation
R 50.1.108-2016, introduces compliance layers
largely absent from ILAC P10 (e.g., alignment
to state-regulated measurement uniformity and
national terminology/controls), thereby treating
traceability simultaneously as an accreditation
requirement and a state-governed metrological
obligation. Elsewhere, policy emphasis can
be purposefully tailored: SAC-SINGLAS 006
explicitly anchors reference material traceability
to ISO 17034 and scheme documents; SAAC
A-04-05 frames the objective as traceability to
“international units”; and CNAS GL033 provides
prescriptive, equipment-level traceability guidance
for construction engineering that goes beyond
ILAC P10’s general policy scope.
We can also describe the continuous chain of
traceability by identifying organized structure of
levels of standards. The number of levels is not
exhaustive and depends on the application.
