Certified reference materials and ISO 17034
Certified reference materials carry a certified value with uncertainty and traceability from a competent producer. ISO 17034 accreditation is the mark of that competence.
In chemical and physical testing, certified reference materials provide traceability where calibration of an instrument alone does not. ISO/IEC 17025 clause 6.5 recognises certified values of CRMs from a competent producer as a route to traceability; ISO 17034 defines that competence.
In temperature and humidity work
- Fixed-point cells (water triple point, gallium, indium, tin, zinc) function as physical references with certified values.
- Saturated salt solutions for humidity have tabulated equilibrium RH values with stated uncertainties; commercially certified versions exist.
- Certified thermometers are not CRMs — they are calibrated instruments.
Whatever the reference, the rule is the same: the certificate must state the value, its uncertainty and the traceability route.
Frequently asked questions
- Is a manufacturer's 'reference standard' a CRM?
- Only if it is certified by a producer meeting ISO 17034 (or an NMI) with a certificate stating value, uncertainty and traceability.
References
- [1]ISO 17034:2016 — General requirements for the competence of reference material producers
- [2]ISO/IEC 17025:2017 — General requirements for the competence of testing and calibration laboratories
General technical guidance written against the cited sources. It is not regulatory or legal advice and does not replace the applicable standard, guideline or a qualified reviewer's judgement.
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