National Measurement Accreditation Scheme

STL are accredited by the Department of Trade and Industry via the National Measurement Accreditation Scheme (NAMAS). This covers all aspects of laboratory operations, such as organization of the laboratory and methodology, equipment and staff training, quahty-control systems and storage of data. The company acquired the first accreditation in the UK for the analysis of organic compounds by GC-MS. It also operates appropriate procedures to conform with the Department of Health s Good Laboratory Practice (GLP) recommendations. 

The laboratories are inspected annually by the National Measurement Accreditation Scheme (NAMAS) and for conformity to GLP. Part of the inspection is a vertical audit, which involves tracing a sample from the moment it is dehvered to the laboratory to when the result is reported. All the records of its passage through the system are traced. For... 

While the establishment and implementation of national traceability systems is left to the countries and their legislation, the mutual recognition of these national systems calls for an international mechanism, at least if worldwide mutual recognition is aimed at. The MRA of the Meter Convention for national measurement standards and calibration and measurement certificates issued by NMIs [2] can be expected to at least provide for one important aspect of the task, namely the establishment of international equivalence at the national standards level. Together with the success of the work currently carried out by the International Laboratory Accreditation Cooperation (ILAC) for the harmonization of national laboratory accreditation schemes, the MRA will be the key to comparability and hence to ac-... 

At the local level, we can achieve traceability by purchasing standards from laboratories that have been accredited for their preparation by the body responsible for the national standard. In the UK, the appropriate body is UKAS (The United Kingdom Accreditation Service, part of NPL) and in the USA, the National Institute of Standards and Technology (NIST). Each country has its own body which in turn participates in the international measurement system. (The overall scheme is shown in Figure 15.1.) By this means, traceability is maintained from local to international level. 

A most useful, and highly recommended, document that provides an excellent model of a standard scheme for the cahbration and use of gamma spectrometry systems is pubhshed by the American National Standards Institute as standard ANSI N42.14-1999 (Committee N42 is the Accredited Standards Committee). Any laboratory following this standard is well on the way to having a universally acceptable measurement scheme ... 

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