The article discusses various types of reference materials and their certification by NIST (National Institute of Standards and Technology). The key points are:
1. Reference Material (RM): A homogeneous and stable material used for measurement purposes, with properties that may be quantitative or qualitative.
2. Certified Reference Material (CRM): An RM with a metrologically valid procedure for specified properties, accompanied by a certificate providing property values, uncertainties, and traceability.
3. NIST Standard Reference Material (SRM): A CRM issued by NIST that meets additional certification criteria and is provided with a certificate or certificate of analysis.
4. NIST Reference Material (NRM): An RM issued by NIST with a report of investigation instead of a certificate, used for scientific research or material evaluation.
5. NIST Research Grade Test Material (RGT): A material evaluated during SRM/RM development, distributed in interlaboratory comparisons to determine fit for purpose.
6. NIST Traceable Reference Material (NTRM): A commercially-produced RM with traceability to NIST standards, recognized by a regulatory authority as equivalent to a CRM.
7. NIST Certified Value: A value on an SRM certificate with the highest confidence in accuracy, where all known bias sources have been investigated.
8. NIST Reference Value: A best estimate of the true value on a certificate or report where all bias sources have not been fully investigated.
9. NIST SRM Certificate/Certificate of Analysis: A document containing material name, description, intended purpose, certified property values, associated uncertainties, and technical information for proper use.
10. NIST Certificate of Traceability: A document stating protocols and measurement pathways supporting NTRM claims to NIST standards.
11. NIST RM Report of Investigation: A document issued with a NIST RM containing technical information for proper use, without NIST certified values.
12. NIST Report of Analysis (ROA): An internal document containing SRM certification information, manufacturing details, and certification procedures.
The article emphasizes the importance of well-defined reference materials and their certification for accurate measurements in various fields.
Source: https://www.nist.gov/srm/srm-definitions
Keywords: Metrology, Reference, Material, Standard, Certification
