Metrology in Chemistry
Background
Metrology is the science of measurement and its application. As one of the stream of metrology, metrology in Chemistry focuses on the study of comparability and traceability of chemical measurements to ensure the reliability of results. This is essential in establishing global mutual recognition of analytical results thereby to provide a technical foundation for wider agreements related to international trade, commerce and regulatory issues. Comparability and metrological traceability are normally established through participation in inter-comparisons organized by regional/international metrology organisations like the International Bureau of Weights and Measures (BIPM) and Asia Pacific Metrology Programme (APMP), and the use of certified reference materials.
Since May 2005, the Government Laboratory (GL) has been included as a Designated Institute, in the field of metrology in chemistry for Hong Kong, China, under the Mutual Recognition Arrangement of the International Committee for Weights and Measures (CIPM MRA). Normally, National Metrology Institute (NMI) is institute designated by the national governmental or other official authority of the Member State of the Metre Convention as being responsible for national measurement standards whereas Designated Institutes (DIs) are specialist institutes appointed by government, an appropriate authority, or in some cases the NMI itself when it is authorized to do so, to deal with metrological responsibilities for certain national standards and associated services that are not covered by the activities of the NMI. Currently, the CIPM MRA has been signed by the representatives of 106 NMIs and covers a further 153 DIs. Before that, GL became a full member of the APMP in November 2004. Besides, GL is also the founding member of the Co-operation on International Traceability in Analytical Chemistry (CITAC). To fulfill its commitments as a Designated Institute, GL has been an accredited proficiency testing scheme provider since August 2006 and an accredited reference materials producer since December 2010. Over the years, GL has actively participated in meetings, workshops and symposiums organized by Asia-Pacific Economic Cooperation (APEC), APMP, BIPM, CITAC and other international and regional organisations. Through these regional and international activities and collaboration, GL continues contributing to the development and prosperity of Hong Kong and to the international efforts in building a firm and harmonized scientific measurement infrastructure for international trade, commerce and regulatory affairs.
CMCs claim
With support of the results obtained from key comparisons organized by international metrology organisations, National metrology institutes or designated institutes are eligible to apply a Calibration and Measurement Capabilities (CMCs) claim which is to be included in the Key Comparison Database (KCDB) under the Mutual Recognition Arrangement of the International Committee for Weights and Measures (CIPM MRA). https://www.bipm.org/kcdb/
CMCs are internationally recognized as the best measurement capability that a metrology institute could possess. With the CMCs claim, the institute can disseminate traceability to its customers through services such as
1. provision of calibrations or reference value
2. provision of certified reference materials (CRMs)
The CMCs claim obtained by the Government Laboratory: https://data.gov.hk/en-data/dataset/hk-govtlab-cmc-cmc
Reference Materials Production
GL is Hong Kong, China's Designated Institute for metrology in chemistry under the CIPM MRA and has the responsibility of disseminating traceability of chemical measurements to local laboratories. Provision of certified reference materials with property values traceable to stated references is a means of disseminating traceability, and testing laboratories could validate their analytical methods and establish the traceability of their measurements through the use of appropriate reference materials.
In December 2010, GL was accredited as a reference material producer in accordance with the international standard ISO Guide 34:2009. The scope of accreditation has been extended to cover pure substance reference materials in November 2011. Over the years, GL commissioned the production of several reference materials such as reference materials for trace elements in herb and seafood, pesticides in tea, melamine in milk and high purity melamine reference material. At the time of production, reference materials of similar nature are not available but are in need by the local testing community. Therefore the reference materials produced are of use to the local laboratories and the wider testing community with relevant operation. In January 2019, GL has successfully transited to the latest standard ISO 17034:2016 for production of reference material.
Reference materials produced by GL will normally be issued free of charge under the following conditions:
- to support the testing laboratories in Hong Kong in seeking accreditation;
- to support the outsourcing activities of the GL;
- to honour the commitments of GL as a Designated Institute under the CIPM MRA; and
- other conditions at the discretion of the Government Chemist.
If you have any enquires about the reference materials produced by GL, please contact us.
International Collaboration
As a member of the international metrology community, GL keeps close contact with other national metrology institutes through regular participation in related meetings and technical exchange. Besides, GL continues to collaborate with the local and mainland inspection authorities and overseas testing and metrology institutes to promote the chemical metrology in the region. Recent collaboration programmes are summarized in the attached table.