National measurement institutes

The BERM symposia have served further to clarify understanding of the basic attributes of a good reference standard that is indispensable for establishing new frontiers in the science of measurements, and to highlight the invaluable infrastructure and proven record of metrological excellence available at the National Measurement Institutes to accomplish such tasks. 

Greater co-operation among producers could be developed. The World Wide Web has provided a model of sharing information based on very clear technical principles and formats, but with no formal bureaucracy or external control. Researchers using the Web can move easily among computers of many research institutions that are linked to the Internet. Perhaps the National Measurement Institutions that produce RM could make their instruments and laboratories just as open and available to researchers who are characterizing a new material (Rasberry 1998). 

Science cannot be performed without an accurate system of measurement, which is globally standardized and compulsory. Units and standards of measurement are agreed upon and harmonized on an international basis by the Bureau International des Poids et Mesures in Sevres, France, and by the International Organization for Standardization in Geneva, Switzerland. The units and standards are then laid down in national laws. Nearly all countries have accepted the Systeme International d Unites (SI units) as their system of measurement. This also applies to countries that had been accustomed to use British units like Australia, Canada, South Africa and the United States. In Britain, SI units are official from January 2010. The valid standards are available from the competent bureaus, for example Bureau International des Poids et Mesures, www.bip.fr National Measurement Institute (Australia), www.measurement.gov.au National Institute of Standards and Technology (NIST, USA), www.physics.nist.gov/ Pubs/SP811/... 

Graham Trout, National Measurement Institute, Pymble, Australia. 

Acknowledgements Michael Verrall and Greg Hitchen (CSIRO) assisted in SEM work. The National Measurement Institute allowed use of the absorbance spectrophotometer. Western... 

The Valid Analytical Measurement (VAM LGC 2005) program of the LGC (the U.K. National Measurement Institute for chemical measurements) typifies a modern approach to quality in chemical measurements. The program s six principles are a clear exposition of the important aspects of making reliable analytical measurements ... 

Many countries have established national measurement institutes to oversee their metrology systems and obligations to the Treaty of the Metre. Sometimes chemistry and other sciences are separated (as in the National Physical Laboratory and the LGC in the United Kingdom), but increasingly chemical mea-... 

Analysis by an expert laboratory of high metrological quality. This will often be one or more reference laboratories such as a national measurement institute. 

The organizer of an interlaboratory study to assign a quantity value to a reference material is usually a national or international certifying authority, such as the International Atomic Energy Agency (United Nations), the Community Bureau of Reference (European Union), or a national measurement institute. 

The top of the chain is the SI unit of amount-of-substance concentration mol dm 3 (mol L1). A certificate from the National Measurement Institute gives confidence to the certifying authority that the amount-of-substance... 

If the analyst in a field laboratory can identify a CRM for calibration of working calibration solutions, and its certificate gives sufficient evidence that the CRM embodies a metrologically traceable quantity value, then his or her work is just about done (figure 7.10). The intricacies of what national measurement institutes and calibration laboratories did to ensure that the CRM has metrologically traceable quantity values are all paid for in the certificate. 

Perhaps if you have a resourceful and supportive national measurement institute, you might be able to persuade it to organize an interlaboratory certification to provide appropriate calibration materials, as has been done in Australia by the grain industry for protein measurements. 

Standard Reference Materials Certified samples sold by the U.S. National Institute of Standards and Technology (or national measurement institutes of other countries) containing known concentrations or quantities of particular analytes. Used to standardize testing procedures in different laboratories. 

Establishing the traceability chain of a result of a measurement is too long and too expensive a process for an analyst to carry out the analyst must be able to obtain ASs from reference material producers and/or National Measurement Institutes (NMIs), the values of which can be used as stated references that puts the burden of such a programme (with justifications) on producers and NMIs. 

In view of these issues, we have over several years undertaken a substantial research programme to develop definitive methods appropriate for in-house certification of matrix RMs, particularly for analytes at trace levels. These definitive measurement methods, most of which use isotope dilution mass spectrometry (IDMS), been the subject of extensive validation, including CCQM key comparisons and pilot studies involving other national measurement institutes. Hence, we are now able to augment interlaboratory data with data obtained at LGC using these very accurate measurements. We have also... 

Key words Primary methods Traceability Uncertainty National Measurement Institute... 

As for primary methods of measurement, it is sensible to interpret highest metrological quality (at least) as providing traceable results . Additionally, one could demand that results of the highest metrological quality should not only be traceable, but also carry as small an uncertainty as possible at a given point in time. It needs to be examined whether primary methods of measurement have an exceptional property that is not found in other methods of measurement, and one must - for reasons of scientific honesty - insist on a property inherent to the method, not its operation or, ever more restrictive, its operation within the walls of a National Measurement Institute. Otherwise, we should try to define just the primary operation or execution of a method, as it is futile to invent methods (in a Platonian sense) that cannot be practiced or are not practicable. 

The National Physical Laboratory (NPL) is the UK s National Measurement Institute which sits at the heart of the NMS. For more than a century NPL has developed and maintained the UK s primary measurement standards. These standards underpin an infrastructure of traceability throughout the UK and fhe world which ensures accuracy and consistency in measurement The national primary standards, which constitute the basis of measurement in the UK, are maintained in strict accordance with internationally agreed recommendations. They are based on the International System of Units (SI). 

Figure 2 The organization of the BIPM Mutual Recognition Arrangement (MRA), agreed in 1999 between the directors of the national measurement institutes of 38 Member States and representatives of two international organizations. (Reproduced with...

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