What is a Reference Material (RM)?

As defined by ISO-REMCO at the annual meeting in Geneva, 2005.

Material, sufficiently homogeneous and stable with respect to one or more specified properties, which has been established to be fit for its intended use in a measurement process.
NOTE 1: RM is a generic term
NOTE 2: Properties can be quantitative or qualitative, e.g., identity of substances or species.
NOTE 3: Uses may include the calibration of a measurement system, assessment of a measurement procedure, assigning values to other materials, and quality control.
NOTE 4: An RM can only be used for a single purpose in a given measurement.


What is a Certified Reference Material (CRM)?

As defined by ISO-REMCO at the annual meeting in Geneva, 2005.

Reference material, characterised by a metrologically valid procedure for one or more specified properties, accompanied by a certificate that provides the value of the specified property, its associated uncertainty, and a statement of metrological traceability.
NOTE 1: The concept of value includes qualitative attributes such as identity or sequence. Uncertainties for such attributes may be expressed as probabilities.
NOTE 2: Metrologically valid procedures for the production and certification of reference materials are given in, among others, ISO 17034 and Guide 35.
NOTE 3: ISO Guide 31 gives guidance on the contents of certificates.


What is a Metrological Quality Control (MQC) Material?

Is a reference material designed to be used to provide ‘evidence of control’ for a given system, which whilst homogenous and stable, may not have the complete value assignment, traceability, and uncertainty budget associated with a CRM.

Materials in this classification include those using a calculated ratio to establish control e.g. Starna products RM-TX, DNACON 260/280


What is accreditation?

Accreditation is the formal recognition of the competence of a body or an organisation for a well defined purpose. Accreditation of a laboratory to ISO/IEC 17025 involves assessment of the technical competence and capability of the laboratory and its personnel. In practice it is the procedure by which a laboratory is assessed to perform a specific range of tests or measurements. Specific areas examined include infrastructure and staff qualifications; in addition to checks that an adequate quality management scheme is in place. The accreditation overs the range of materials tested or analysed, the tests performed, the method and equipment used and the accuracy or precision expected, and is specific to the facility and the test.


What is qualification?

Qualification is a structured approach to providing ‘evidence of control’ to a regulatory authority, for a given system.

Analytical Instrument Qualification (AIQ) is usually specified in terms of four specific phases:
Design Qualification (DQ)
Installation Qualification (IQ)
Operational Qualification (OQ)
Performance Qualification (PQ)


Why is Calibration important?

Place any equipment in the environment of choice, and immediately the environment will begin to act on that equipment causing change; and degradation in performance. This so called drift, causes your results to become unreliable and no longer ‘fit for purpose’. Whilst drift cannot be eliminated it can be detected and contained through the process of calibration. In the pharmaceutical industry, a system where drift has occurred to an unacceptable level is deemed to be ‘out of control’. However, by inference, this same environment will also act on your Certified Reference Materials (CRM) to a greater or lesser degree, depending on how they are kept, etc. and these materials must be checked/re-certified to ensure that the values you are placing all your faith in haven’t also significantly changed.


What is traceability?

National Metrology Institutes (NMIs), for example National Institute for Standards and Technology USA (NIST), National Physical Laboratory UK (NPL), etc. work together to agree a common definition for measurement units. These then make up the International System of units, SI. e.g. kilogram, second, metre, ampere, candela, and the Standards Laboratories will then ‘realise’ units from internationally agreed SI definitions to establish primary national measurement scales. Traceability is defined in ISO/IEC Guide 99:2007 International Vocabulary of Metrology (VIM) - as the “property of a measurement result whereby the
result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty”


How is this traceability achieved with Starna materials?

Where appropriate, calibration certificates are issued where the certification process has established traceable links to an NMI primary reference material. In most cases this is a NIST Standard Reference Material (SRM) to determine the appropriate parameters.

Using procedures consistent with the operation within an ISO/IEC 17025 and ISO 17034 accredited environment, all certification
measurements are bracketed by use of an appropriate NIST primary CRM. In addition the fundamental characteristic of the reference spectrophotometer are periodically established using physical references. For example, wavelength calibration is verified using line spectra from a mercury emission source.


What does traceability achieve?

Measurements are made against a consistent set of units and there is International equivalence of national measurement scales. It also means that compatible measurements are made across national borders, resulting in unambiguous and reliable communication of specifications.