Performance criteria for reference measurement procedures and reference materials

2015 ◽  
Vol 53 (6) ◽  
Author(s):  
Heinz Schimmel ◽  
Ingrid Zegers
Keyword(s):  
Reference Materials ◽  
International System ◽  
Metrological Traceability ◽  
International Standards ◽  
Performance Criteria ◽  
Systematic Bias ◽  
End User ◽  
Reference Measurement ◽  
System Of Units ◽  
Measurement Results

AbstractThe concept of metrological traceability of measurement results to property values assigned to measurement standards of higher metrological order or to the International System of Units (SI) through sequential calibrations, using reference materials and reference measurement procedures, plays a key role in ensuring that end user measurement procedures perform at an acceptable level in the clinical context. The aim is that measurement results produced over time or by different end users or with different end user measurement procedures for the same measurand will be equivalent within their corresponding uncertainties. These goals can only be reached under certain conditions and if requirements laid down in international standards on calibration concepts, reference measurement procedures and reference materials are fulfilled. Calibration hierarchies have to be implemented correctly and parameters contributing to measurement uncertainty and systematic bias need to be controlled and eliminated, respectively, by technically improving methods and reference materials and intermediate calibrators used for effectively achieving equivalence of measurement results and for meeting analytical performance requirements for in vitro diagnostic devices.

Metrological Traceability and Roles of Certified Reference Materials

2016 ◽  
Vol 4 (2) ◽  
pp. 81-83
Author(s):  
Akiharu Hioki ◽  
Keyword(s):  
Reference Materials ◽  
Certified Reference Materials ◽  
International System ◽  
Metrological Traceability ◽  
Chemical Analyses ◽  
International Reference ◽  
Calibration And Validation ◽  
Traceability System ◽  
System Of Units ◽  
Metre Convention

Metrological traceability to an international reference, the International System of Units (SI) if possible, is important for the reliability of measurements. The international traceability system under the Metre Convention is briefly introduced. The simplest way to secure metrological traceability in chemical analyses is to utilise certified reference materials (CRMs) for calibration and validation. Finally, as examples of CRMs, NMIJ ones are described.

Certified Reference Materials and Metrological Traceability for Mycotoxin Analysis

2019 ◽  
Vol 102 (6) ◽  
pp. 1695-1707
Author(s):  
Zhen Guo ◽  
Xianjiang Li ◽  
Hongmei Li
Keyword(s):  
Reference Materials ◽  
Certified Reference Materials ◽  
Mutual Recognition ◽  
Metrological Traceability ◽  
International Standards ◽  
Great Effort ◽  
Legal Metrology ◽  
International Laboratory Accreditation Cooperation ◽  
Weights And Measures ◽  
Measurement Results

Abstract In the past decade, with the signing of the joint declaration by the International Bureau of Weights and Measures (BIPM), the International Organisation of Legal Metrology, the International Laboratory Accreditation Cooperation, and the International Organization for Standardization, and the issuing of new international standards such as ISO/IEC 17025 and ISO 13528, metrological traceability has become more and more important for the mutual recognition of measurement results. It is found that the important factors for ensuring the accuracy of results are not only relevant to calibrants but also to the analysis procedure. This paper focuses on the analysis of key factors that affect measurement results, such as analytical methods, reference materials (RMs), and proficiency testing of mycotoxins. The Capacity Building and Knowledge Transfer Programme for mycotoxins, led by the BIPM, which aims to establish a global measurement system traced to the Système International d’Unités (SI), is well illustrated. Furthermore, this paper suggests to stakeholders that great effort is needed to promote the effective use of certified RM resources that are traced to the SI and globally recognized by the International Committee for Weights and Measures to finally realize “one measurement, global recognition.”

Certified Reference Materials and Metrological Traceability for Mycotoxin Analysis

2019 ◽  
Vol 102 (6) ◽  
pp. 1695-1707
Author(s):  
Zhen Guo ◽  
Xianjiang Li ◽  
Hongmei Li
Keyword(s):  
Reference Materials ◽  
Certified Reference Materials ◽  
Mutual Recognition ◽  
Metrological Traceability ◽  
International Standards ◽  
Great Effort ◽  
Legal Metrology ◽  
International Laboratory Accreditation Cooperation ◽  
Weights And Measures ◽  
Measurement Results

In the past decade, with the signing of the joint declaration by the International Bureau of Weights and Measures (BIPM), the International Organisation of Legal Metrology, the International Laboratory Accreditation Cooperation, and the International Organization for Standardization, and the issuing of new international standards such as ISO/IEC 17025 and ISO 13528, metrological traceability has become more and more important for the mutual recognition of measurement results. It is found that the important factors for ensuring the accuracy of results are not only relevant to calibrants but also to the analysis procedure. This paper focuses on the analysis of key factors that affect measurement results, such as analytical methods, reference materials (RMs), and proficiency testing of mycotoxins. The Capacity Building and Knowledge Transfer Programme for mycotoxins, led by the BIPM, which aims to establish a global measurement system traced to the Système International d’Unités (SI), is well illustrated. Furthermore, this paper suggests to stakeholders that great effort is needed to promote the effective use of certified RM resources that are traced to the SI and globally recognized by the International Committee for Weights and Measures to finally realize “one measurement, global recognition.”

scholarly journals Metrological traceability of oceanographic salinity measurement results

Ocean Science ◽  
2011 ◽  
Vol 7 (1) ◽  
pp. 45-62 ◽  
Author(s):  
S. Seitz ◽  
R. Feistel ◽  
D. G. Wright ◽  
S. Weinreben ◽  
P. Spitzer ◽  
...  
Keyword(s):  
Time Scales ◽  
International System ◽  
Metrological Traceability ◽  
Point Of View ◽  
Measured Quantity ◽  
Additional Contribution ◽  
Small Uncertainty ◽  
System Of Units ◽  
Measurement Results ◽  
Property Changes

Abstract. Consistency of observed oceanographic salinity data is discussed with respect to contemporary metrological concepts. The claimed small uncertainty of salinity measurement results traceable to the conductivity ratio of a certified IAPSO Standard Seawater reference is not metrologically justified if results are compared on climatic time scales. This applies in particular to Practical Salinity SP, Reference Salinity SR, and the latest estimates of Absolute Salinity using the TEOS-10 formalism. On climate time scales an additional contribution to the uncertainty that is related to unknown property changes of the reference material must be accounted for. Moreover, when any of these measured or calculated quantity values is used to estimate Absolute Salinity of a seawater sample under investigation, another uncertainty contribution is required to quantify the accuracy of the equations relating the actually measured quantity to the Absolute Salinity. Without accounting for these additional uncertainties, such results cannot be used to estimate Absolute Salinity with respect to the International System of Units (SI), i.e. to the unit chosen for the mass fraction of dissolved material in the sample, which is "g kg−1". From a metrological point of view, such deficiencies in the calculations involving other quantities will produce SI-incompatible results. We outline how these problems can be overcome by linking salinity to primary SI measurement standards.

scholarly journals Metrological traceability of oceanographic salinity measurement results

2010 ◽  
Vol 7 (4) ◽  
pp. 1303-1346 ◽  
Author(s):  
S. Seitz ◽  
R. Feistel ◽  
D. G. Wright ◽  
S. Weinreben ◽  
P. Spitzer ◽  
...  
Keyword(s):  
Time Scales ◽  
International System ◽  
Metrological Traceability ◽  
Point Of View ◽  
Measured Quantity ◽  
Additional Contribution ◽  
Small Uncertainty ◽  
System Of Units ◽  
Measurement Results ◽  
Property Changes

Abstract. Consistency of observed oceanographic salinity data is discussed with respect to contemporary metrological concepts. The claimed small uncertainty of salinity measurement results traceable to the conductivity ratio of a certified IAPSO Standard Seawater reference is not metrologically justified if results are compared on climatic time scales. This applies in particular to Practical Salinity SP, Reference Salinity SR, and the latest estimates of Absolute Salinity using the TEOS-10 formalism. In climate time scales an additional contribution to the uncertainty that is related to unknown property changes of the reference material must be accounted for. Moreover, when any of these measured or calculated quantity values is used to estimate Absolute Salinity of a seawater sample under investigation, another uncertainty contribution is required to quantify the accuracy of the equations relating the actually measured quantity to the Absolute Salinity. Without accounting for these additional uncertainties, such results cannot be used to estimate Absolute Salinity with respect to the International System of Units (SI), i.e. to the unit chosen for the mass fraction of dissolved material in the sample, which is "g/kg". From a metrological point of view, such deficiencies in the calculations involving other quantities will produce SI-incompatible results. We outline how these problems can be overcome by linking salinity to primary SI measurement standards.

scholarly journals Salinity and relative humidity: climatological relevance and metrological needs

ACTA IMEKO ◽  
2015 ◽  
Vol 4 (4) ◽  
pp. 57 ◽  
Author(s):  
Rainer Feistel
Keyword(s):  
Relative Humidity ◽  
State Of The Art ◽  
Numerical Models ◽  
International System ◽  
Metrological Traceability ◽  
Ocean Surface ◽  
International Standards ◽  
Surface Salinity ◽  
Climatic Trends ◽  
System Of Units

Water plays the leading thermodynamic role in Earth's 'steam engine' climate. Followed by clouds and CO<sub>2</sub>, water vapour in the atmosphere is dominating the greenhouse effect. Evaporation from the ocean surface is the main route of energy export from the ocean, the rate of which is known with poor 20 % uncertainty only. Regional climatic trends in evaporation and precipitation are reflected in small changes of ocean surface salinity.<br /> Observational data of salinity and relative humidity need to be globally comparable within requisite uncertainties over decades and centuries, but both quantities rely on century-old provisional standards of unclear stability, and on ambiguous definitions. This increasingly urgent and long-pending problem can only be solved by proper metrological traceability to the International System of Units (SI). Consistent with such SI-based definitions, state-of-the-art correlation equations for thermophysical properties of water, seawater, ice and humid air such as those available from the recent oceanographic standard TEOS-10 need to be developed and adopted as joint international standards for all branches of climate research, in oceanography, meteorology and glaciology for data analysis and numerical models.<br /> The IAPSO/SCOR/IAPWS Joint Committee on Seawater JCS is targeting at these aims in cooperation with BIPM, WMO and other international bodies.

Problems of ensuring metrological traceability of measurement results of indicators of quality for food products and food raw materials

2020 ◽  
pp. 64-70
Author(s):  
Mariya Y. Medvedevskikh ◽  
Anna S. Sergeeva
Keyword(s):  
Reference Materials ◽  
Mass Fraction ◽  
Nutritional Value ◽  
Animal Feed ◽  
Raw Materials ◽  
Meat Products ◽  
Metrological Traceability ◽  
Food Products ◽  
Freeze Dried ◽  
Measurement Results

The article raises the problem of ensuring metrological traceability of the measurement results of indicators of quality and nutritional value for food products and food raw materials: water (moisture), nitrogen (protein, crude protein), fat, ash and carbohydrates. The problem under consideration can be solved by applying reference materials of food composition, traceable to state primary measurement standards GET 173-2017 and GET 176-2019 and primary reference measurement procedures (PRMP), for attestation of measurement procedures and accuracy checking of measurement results. The article discusses the results of the PRMP development of mass fraction of fat, ash and carbohydrates in food products and food raw materials, as well as mass fraction of crude fat (oil content) in oil crops seeds and products based on them. The paper also presents metrological characteristics of reference materials of composition of dry dairy products, grain-milk dry porridges for nutrition of babies, grain dry porridges for nutrition of babies, egg powder, freeze-dried meat products, animal feed. The results of the work allow for building a chain of metrological traceability from GET 173-2017, GET 176-2019 and PRMP to routine measurement procedures, thereby ensuring the uniformity of measurements of nutritional value of food products.

scholarly journals A Blackbody Design for SI-Traceable Radiometry for Earth Observation

2008 ◽  
Vol 25 (11) ◽  
pp. 2046-2054 ◽  
Author(s):  
P. Jonathan Gero ◽  
John A. Dykema ◽  
James G. Anderson
Keyword(s):  
Phase Transitions ◽  
Temperature Scale ◽  
International System ◽  
Thermal Infrared ◽  
Earth Observation ◽  
International Standards ◽  
Future Climate Change ◽  
Single Temperature ◽  
System Of Units ◽  
Infrared Measurements

Abstract Spaceborne measurements pinned to international standards are needed to monitor the earth’s climate, quantify human influence thereon, and test forecasts of future climate change. The International System of Units (SI, from the French for Système International d’Unités) provides ideal measurement standards for radiometry as they can be realized anywhere, at any time in the future. The challenge is to credibly prove on-orbit accuracy at a claimed level against these international standards. The most accurate measurements of thermal infrared spectra are achieved with blackbody-based calibration. Thus, SI-traceability is obtained through the kelvin scale, making thermometry the foundation for on-orbit SI-traceable spectral infrared measurements. Thermodynamic phase transitions are well established as reproducible temperature standards and form the basis of the international practical temperature scale (International Temperature Scale of 1990, ITS-90). Appropriate phase transitions are known in the temperature range relevant to thermal infrared earth observation (190–330 K) that can be packaged such that they are chemically stable over the lifetime of a space mission, providing robust and traceable temperature calibrations. A prototype blackbody is presented that is compact, highly emissive, thermally stable and homogeneous, and incorporates a small gallium melting point cell. Precision thermal control of the blackbody allows the phase transition to be identified to within 5 mK. Based on these results, the viability of end-to-end thermometric calibration of both single-temperature and variable-temperature blackbodies on orbit by employing multiple-phase-change cells was demonstrated.

scholarly journals Thermodynamic Properties of Seawater, Ice and Humid Air: TEOS-10, Before and Beyond

2018 ◽  
Author(s):  
Rainer Feistel
Keyword(s):  
Hydrological Cycle ◽  
International System ◽  
Metrological Traceability ◽  
Humid Air ◽  
Ongoing Research ◽  
Seawater Salinity ◽  
System Of Units ◽  
Atmospheric Relative Humidity ◽  
Definition Of ◽  
First Time

Abstract. In the terrestrial climate system, water is a key player in the form of its different ambient phases of ice, liquid and vapour, admixed with sea salt in the ocean and with dry air in the atmosphere. For proper balances of climatic energy and entropy fluxes in models and observation, a highly accurate, consistent and comprehensive thermodynamic standard framework is requisite in geophysics and climate research. The new “Thermodynamic Equation of Seawater – 2010” (TEOS-10) constitutes such a standard for properties of water in its various manifestations in the hydrological cycle. TEOS-10 has been recommended internationally in 2009 by the Intergovernmental Oceanographic Commission (IOC) to replace the previous 1980 seawater standard, EOS-80, and in 2011 by the International Union of Geodesy and Geophysics (IUGG) “as the official description for the properties of seawater, of ice and of humid air”. This paper briefly reviews the development of TEOS-10, its novel axiomatic properties, new oceanographic tools it offers, and important tasks that still await solutions by ongoing research. Among the latter are new definitions and measurement standards for seawater salinity and pH, in order to establish their metrological traceability to the International System of Units (SI), for the first time after a century of widespread use. Of similar climatological relevance is the development and recommendation of a uniform standard definition of atmospheric relative humidity that is unambiguous and rigorously based on physical principles.

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