68
6 Reference Materials in Chemical Measurements
material. Note: an SRM is prepared and used for three main purposes: (1) to help
develop accurate methods of analysis; (2) to calibrate measurement systems used
to facilitate the exchange of goods, institute quality control, determine performance
characteristics, or measure a property at the state-of-the-art limit; and (3) to ensure
the long-term adequacy and integrity of measurement quality assurance programs.
Another approach of NIST is link to the production of NIST Traceable Reference
Material
TM (NTRM), an RM with a well-defined traceability linkage to existing
NIST standards for chemical measurements. This traceability linkage is established
via criteria and protocols defined by NIST to meet the needs of the metrological
community to be served. RMPs adhering to these requirements are allowed use of
the NTRM trademark, which may be recognized by a regulatory authority as being
equivalent to a CRM.
An important international forum dealing with RMs and CRMs is the Committee
for Reference Materials REMCO, acting within the framework of the International
Organization for Standardization ISO. Committee ISO/REMCO was founded in 1975
and presently ISO/REMCO is composed of 32 participating and 38 observer members. The main aims of the activity are related to establishing concepts, terms and
definitions related to RMs; to specify the basic characteristics of RMs as required
by their intended use; to propose actions on RMs required to support other ISO
activities; to prepare guidelines for ISO technical committees when dealing with
RM issues. ISO/REMCO cooperates with many institutions, including regional and
national standardization organizations and metrological institutes. The effect of the
activities of ISO/REMCO is evidenced by a number of guides and technical reports
issued in recent years, outlined below.
ISO Guide 30:2015 Reference Materials. Selected Terms and Definitions, provides
definitions of the following terms: reference material, certified reference material,
candidate reference material, matrix reference material, sample and minimum sample size, as well as production batch (lot), characterization and value assignment,
homogeneity, stability, lifetime and period of validity and many more items related
to RMs.
ISO Guide 31:2015 Reference Materials. Contents of Certificates, Labels and
Accompanying Documentation, aims to guide RMPs in preparing clear and concise
documentation to accompany their RM. This information can be used by RMs users
and other stakeholders in confirming the suitability of an RMs or CRMs. This guide
also contains the minimum requirements for a label attached to the RM container.
ISO Guide 33:2015 Reference Materials. Good Practice in Using Reference Materials, describes good practice in using RMs and CRMs by laboratories in measurement
processes. These uses include the assessment of precision and trueness of measurement methods, quality control, assigning values to materials, calibration, and the
establishment of conventional scales. It provides important information on the characteristics of various types of RMs in respect of their different applications.
ISO Guide 35:2017 Reference Materials. Guidance for Characterization and
Assessment of Homogeneity and Stability,’ which explains concepts and provides
6 Reference Materials in Chemical Measurements
material. Note: an SRM is prepared and used for three main purposes: (1) to help
develop accurate methods of analysis; (2) to calibrate measurement systems used
to facilitate the exchange of goods, institute quality control, determine performance
characteristics, or measure a property at the state-of-the-art limit; and (3) to ensure
the long-term adequacy and integrity of measurement quality assurance programs.
Another approach of NIST is link to the production of NIST Traceable Reference
Material
TM (NTRM), an RM with a well-defined traceability linkage to existing
NIST standards for chemical measurements. This traceability linkage is established
via criteria and protocols defined by NIST to meet the needs of the metrological
community to be served. RMPs adhering to these requirements are allowed use of
the NTRM trademark, which may be recognized by a regulatory authority as being
equivalent to a CRM.
An important international forum dealing with RMs and CRMs is the Committee
for Reference Materials REMCO, acting within the framework of the International
Organization for Standardization ISO. Committee ISO/REMCO was founded in 1975
and presently ISO/REMCO is composed of 32 participating and 38 observer members. The main aims of the activity are related to establishing concepts, terms and
definitions related to RMs; to specify the basic characteristics of RMs as required
by their intended use; to propose actions on RMs required to support other ISO
activities; to prepare guidelines for ISO technical committees when dealing with
RM issues. ISO/REMCO cooperates with many institutions, including regional and
national standardization organizations and metrological institutes. The effect of the
activities of ISO/REMCO is evidenced by a number of guides and technical reports
issued in recent years, outlined below.
ISO Guide 30:2015 Reference Materials. Selected Terms and Definitions, provides
definitions of the following terms: reference material, certified reference material,
candidate reference material, matrix reference material, sample and minimum sample size, as well as production batch (lot), characterization and value assignment,
homogeneity, stability, lifetime and period of validity and many more items related
to RMs.
ISO Guide 31:2015 Reference Materials. Contents of Certificates, Labels and
Accompanying Documentation, aims to guide RMPs in preparing clear and concise
documentation to accompany their RM. This information can be used by RMs users
and other stakeholders in confirming the suitability of an RMs or CRMs. This guide
also contains the minimum requirements for a label attached to the RM container.
ISO Guide 33:2015 Reference Materials. Good Practice in Using Reference Materials, describes good practice in using RMs and CRMs by laboratories in measurement
processes. These uses include the assessment of precision and trueness of measurement methods, quality control, assigning values to materials, calibration, and the
establishment of conventional scales. It provides important information on the characteristics of various types of RMs in respect of their different applications.
ISO Guide 35:2017 Reference Materials. Guidance for Characterization and
Assessment of Homogeneity and Stability,’ which explains concepts and provides