Metrology laboratory accreditation

RMs, preferably certified by reputable and accredited laboratories, provide vital contributions to the science of chemistry, to industry in its quest for quality assurance, and to commerce for consensus product characterizations. All such RMs should have designated values bonded to the units of the SI, where possible through national metrology laboratories [9-13],... 

Abstract Current developments in Germany for establishing a traceability system for chemical measurements are reported. The focus is on a dissemination mechanism which employs chemical calibration laboratories accredited within the framework of the German Calibration Service (DKD) and acting as multipliers between the national standards level and the user level by providing the user with calibration means which are traceable to the SI via national standards. At the national standards level, a network of high-level chemistry institutes coordinated by the national metrology institute, PTB, provides the primary references for chemical measurements. 

To have a network of laboratories at the top of a trace-ability system for chemical measurements instead of just the national metrology institute seems to be a requirement typical of metrology in chemistry and is under consideration in many industrialized countries, because the competence for chemical analysis in most countries (except U.S.A.) largely lies outside the domain of the metrology institutes. Another example that underpins this view is the development of metrology in chemistry in Switzerland, where the Swiss Federal Office of Metrology and Accreditation (METAS) and the Swiss Federal Laboratories for Materials Testing and Research (EMPA) jointly provide the national references for chemical measurements [2]. 

Abstract Reliable, traceable and comparable measurements provide the rational basis for evaluation of the quality of a result and the starting point for recognized laboratory accreditation in any national area. Modern medical diagnostics and treatment involve rapidly rising numbers and types of clinical laboratory measurements, that are reliable. Therefore, the basic principles to be followed to assure the traceability of clinical measurements as required by the Romanian Laws of Metrology are reviewed. Main sources affecting the... 

Accreditation is mainly concerned with routine tests or analysis. It includes the use of reference materials (e.g. LRMs or in-house RMs) for control charts which are hardly available on the market it is hence timely to start producing RMs for routine analysis in high quantities and at low cost for those measurements which have a major economic importance in relation to social and environmental implications as mentioned above, such a production should follow minimum quality requirements to avoid commercialisation and use of bad quality products which would only add to confusion. There is obviously a need to focus/consolidate technical expertise for CRM production in a few centres of excellence and actions should be stimulated to create a possible network of CRM producers which should be composed of practitioners , i.e. experts in both the production of CRMs and the respective analytical fields, so that questions arising from routine laboratories could be readily and practically responded to [44] while efforts made by metrological laboratories to create a system of metrology in chemistry are certainly important, these are far remote from the needs of routine laboratories which, however, carry out the vast majority of analytical work worldwide. Pragmatism should... 

Standardization encompasses a broad range of considerations—from the actual development of a standard to its promulgation, acceptance, and implementation. Also included are the methods of evaluating conformance to a standard—issues such as laboratory accreditation certification of products, processes, systems, services, and personnel metrology and measurement testing and sampling and more. Standardization has become the key to market access and is inherently essential to a sound national economy and to the facilitation of global commerce. 

In summary, the GUM provides rules on the expression of uncertainty for use within standardization, calibration, laboratory accreditation, and metrology services. It also provides the basis for the international comparison of measurement results. 

Checking is performed in accredited laboratories on procedures developed in compliance with stated requirements and approved in the process of testing implementation on CTB 8001-93 or metrological attestation on CTB 8004-93. 

Dybkaer R, Ornemark U, Uldall A, Richter W (1999) Metrology in laboratory medicine - A necessity. Accredit Qual Assur 4 349-351. 

Accreditation by ISO/IEC CASCO, ISO/TC 212, CEN/TC 140, ILAC, EA, APLAC, and NACC Metrological institutes coordinated by BIPM, EURO-MET, APMP, NORAMET, COOMET, and SIM Reference measurement laboratories, preferably organized in networks... 

The GUM approach to uncertainty is rapidly gaining acceptance in metrological institutes and industry, and must be applied in ISO and CEN standards. It should be used in accredited laboratory work but chemists often find the implementation difficult and therefore hesitate [34], Additionally, sometimes, there is a fear that honest GUM uncertainty intervals, which may be wider... 

Fig. 1 Traceability system for the determination of the most important diagnostic markers in human body fluids in Germany. The clinical reference laboratories at the intermediate level providing calibration means to the routine medical laboratories are accredited as calibration laboratories in the framework of the German Calibration Service (DKD) and are firmly linked to the national metrology institute, PTB, by comparison measurements carried out on actual laboratory samples. Accreditation is in part required by the Federal Physicians Council (BAK) or is voluntary. The traceability system is still under development...

Abstract This paper reviews the current state of play of the Mutual Recognition Arrangement created by the International Committee for Weights and Measures in 1999. The aim of the MRA is to provide a framework within which National Metrology Institutes can demonstrate the equivalence of their realisations of the units and quantities of the SI system to which accredited laboratories are traceable. The article offers some views on the need for traceable... 

It is obvious to think of accredited calibration laboratories as the most important link to the working level also in the field of chemical measurements, after the concept of the dissemination of the national measurement standards via accredited calibration laboratories has been successfully applied for more than two decades in metrology in general. 

Fig. 1 Metrological traceability and hierarchy of procedures and materials (according to ISO/IEC 17511). uc(y) Uncertainty BIPM International Bureau of Weights and Measures NMI National Metrology Institute ACL Accredited Calibration Laboratory MCL Manufacturer s Calibration Laboratory ML Manufacturer s Laboratory Mf Manufacturer...

Table 2 Comparison of Cholesterol Reference Method Laborato- tute, NIST National Institute of Standards and Technology (US ry Network (CRMLN) traceability model to the International Or- NMI), IDMS isotope dilution mass spectrometry, ACL accredited ganization for Standardization (ISO) model. BIPM International calibration laboratory, AK Abell-Kendall Bureau of Weights and Measures, NMI National Metrology Insti-...

In line with the objectives of the CCQM Workshop, we have tried to suggest how measurement traceability can be disseminated to field laboratories. An important anticipated evolution in this respect is the fact that the stakeholders dealing with accreditation/metrology/edu-cation/standardization will need to collaborate much more closely to achieve measurable progress. 

The increased attention paid to the concept of traceability and its implementation in the world of chemical measurements has been one of the major goals of metrological activity in recent years. In Romania traceability of chemical measurement has been closely connected with the accreditation of analytical chemistry laboratories. However, this concept has only recently been adopted in this country for clinical measurements. Within this framework an attempt is made to review what traceability means in terms of clinical measurements and what is now being done by the Romanian National Institute of Metrology (INM) to develop the principles of traceability in spectrophotometrical measurements performed in clinical chemistry laboratories. 

Communautaire. Accreditation aims at the reliability of measurement results and enables laboratories to demonstrate technical competence to their customers. Metrological concepts in food science have become a widely discussed topic over the last few years. Representing the top of the international measurement infrastructure, the National Metrology Institutes (NMIs) have the mandate to disseminate the best practice and measurement capabilities to the beld laboratories (FLs) in their countries. The European and international measurement infrastructure needs high-quality tools to assess the reliability and comparability of measurements results in view of the implementation of EU and international policies regarding internal market activities as well as health and consumer protection issues. 

The common goal of EA and IRMM is to demonstrate the reliability and comparability of chemical measurements. This will be mainly achieved by the joint organization of ILCs with traceable reference values of high metrological quality, but also by organizing educational and training activities. Therefore, not only does the IRMM provide a tool for NABs to assess the performance of their accredited laboratories, but it also supports EA in monitoring the efficiency of the EA-MLA. In that sense, the IRMM improves the efficiency of accreditation in chemistry. 

QC and QA are prerequisites to provide reliable analytical results to customers. Reliability is the key word in view of compliance of laboratories with the ISO/ IEC 17025 Standard. Particularly in the held of trace elements analysis, the IMEP process results in a representative picture of the measurement capabilities at a certain point in time on trace elements endorsed in respective EU and international legislation. The general observation is that the majority of laboratories perform very well or satisfactorily in IMEP, but some have serious problems and their claims do not correspond to their actual measurement capability, regardless of whether they are reference, authorized, or accredited laboratories. This emphasizes the fact that the use of IMEP as metrological quality tool is primarily to the benebt of laboratories. The correct application of metrological concepts such as traceability and uncertainty is the basis of providing high-quality and reliable... 

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