Standard Reference Material is a physical substance or artifact provided by an organization like NIST, accompanied by a certificate detailing its exact properties and uncertainty. Metrology labs use these materials to calibrate instruments, validate measurement methods, and establish unbroken chains of traceability. Common examples include pH buffer solutions, precise metal alloys, and calibrated glass filters.
Grab a fresh vial of the pH 7 SRM so we can verify the new bench meter before the auditor gets here.
Never use an SRM for routine daily checks. They are expensive and have expiration dates, so labs keep them sealed until needed for formal calibration or method validation.
Also heard as
- Standard Reference Material
Do not mix it up with
- Check standard: An SRM is an official, certified material used for formal traceability, whereas a check standard is an in-house item used for daily stability checks.
Related terms
NIST traceable
A common label phrase claiming a measurement links back to US national standards, often used loosely.
Traceability
Proof that a result ties back to the SI or another stated reference, with every calibration in between on record.
Primary standard
A standard that gets its value straight from the unit definition, not from calibration against another standard.
NMI
National metrology institute, the body that realizes a country's measurement units at the top of its traceability chain.