scholarly journals Application of systems thinking to the establishment of metrological traceability chains

2021 ◽  
pp. 3-7
Author(s):  
Oleh Velychko ◽  
Tetyana Gordiyenko
Keyword(s):  
Measurement Uncertainty ◽  
Systems Thinking ◽  
Metrological Traceability ◽  
Measuring Instruments ◽  
Measurement Standard ◽  
International Laboratory Accreditation Cooperation ◽  
Traceability Chain ◽  
Measurement Standards ◽  
Calibration Laboratories ◽  
Different Levels

International agreements in the field of metrology and accreditation of calibration laboratories are the basis for establishing global metrological traceability. Important elements of metrological traceability are calibration of measurement standards and measuring instruments, assessment of measurement uncertainty. The International Laboratory Accreditation Cooperation has a specific policy regarding on traceability of measurement results and estimation of measurement uncertainty in calibration. The partial concept diagram around metrological traceability in accordance with the International Vocabulary of Metrology is proposed. This diagram contains a total of nine metrological concepts, which have most of the associative relations. There are associative relations between the concept of metrological traceability chain and concepts of metrological traceability, measurement standard, calibration and calibration hierarchy, and through the concept of measurement standard with the concept of measurement uncertainty. Systems thinking to the analysis of state of proposed terminological system around metrological traceability was applied. For construction of generalized metrological traceability chain, all the established properties of the system elements around the terminology system of metrological traceability were taken into account. Generalized metrological traceability chain for different levels of the calibration hierarchy was proposed. The proposed chain can be used to develop appropriate chains for specific areas of measurement. To achieve this, it is necessary to determine the specific measured value, the required measurement uncertainty for different levels of the calibration hierarchy and select the necessary measurement standards. Such schemes should be used in national metrology institutes and calibration laboratories.

scholarly journals The utility of measurement uncertainty in medical laboratories

2020 ◽  
Vol 58 (9) ◽  
pp. 1407-1413 ◽  
Author(s):  
Federica Braga ◽  
Mauro Panteghini
Keyword(s):  
Measurement Uncertainty ◽  
Metrological Traceability ◽  
Measuring System ◽  
Medical Laboratory ◽  
Management Tool ◽  
Clinical Samples ◽  
Traceability Chain ◽  
Medical Laboratories

AbstractThe definition and enforcement of reference measurement systems, based on the implementation of metrological traceability of patient results to higher-order (reference) methods and/or materials, together with a clinically acceptable level of measurement uncertainty (MU), are fundamental requirements to produce accurate and equivalent laboratory results. The MU associated with each step of the traceability chain should be governed to obtain a final combined MU on clinical samples fulfilling the requested performance specifications. MU is useful for a number of reasons: (a) for giving objective information about the quality of individual laboratory performance; (b) for serving as a management tool for the medical laboratory and in vitro diagnostics (IVD) manufacturers, forcing them to investigate and eventually fix the identified problems; (c) for helping those manufacturers that produce superior products and measuring systems to demonstrate the superiority of those products; (d) for identifying analytes that need analytical improvement for their clinical use and ask IVD manufacturers to work for improving the quality of assay performance and (e) for abandoning assays with demonstrated insufficient quality. Accordingly, the MU should not be considered a parameter to be calculated by medical laboratories just to fulfill accreditation standards, but it must become a key quality indicator to describe both the performance of an IVD measuring system and the laboratory itself.

Investigation of the Accuracy of Reference Instruments for Measuring Vertical Angles by Reference Method of Their Calibration

2020 ◽  
pp. 3-14
Author(s):  
O. M. Samoylenko ◽  
O. V. Adamenko ◽  
B. P. Kukareka
Keyword(s):  
Horizontal Plane ◽  
Opposite Sign ◽  
Reference Method ◽  
Angle Measurement ◽  
Measurement Standard ◽  
Vertical Angle ◽  
Measurement Standards ◽  
Measurement Results ◽  
Electronic Measurement ◽  
Systematic Biases

Reference method for simultaneous calibration of the three and more measurement standards for vertical angle measurement is developed. This method can to use for obtaining the systematic biases of the vertical angles measurements for each of the measuring standards relative of the horizontal plain was averaged from measurement results in time their calibration or comparison. For realization of the reference method was developed the autocollimationel electronic measurement standard for the automatization measurement of the vertical angles SeaLineZero_Standard™ (SLZ_S™). Summary standard deviation (k=1) of the vertical angle measurement relative the horizontal plane, from the results of their calibration by reference method, is not more 0,07ʺ…0,15ʺ. This result was obtained without the use the systematic biases, for each measurement standards, as measurements corrections (with opposite sign). The measuring standards, that were developed and researched, are necessary for obtaining the systematic biases of the vertical angle measurement for total stations and theodolites, that have the normed standard error 0,5ʺ and 1ʺ, when these instruments are calibrating.

scholarly journals Documenting metrological traceability as intended by ISO 15189:2012: A consensus statement about the practice of the implementation and auditing of this norm element

2019 ◽  
Vol 57 (4) ◽  
pp. 459-464 ◽  
Author(s):  
Marc Thelen ◽  
Florent Vanstapel ◽  
Pika Meško Brguljan ◽  
Bernard Gouget ◽  
Guilaine Boursier ◽  
...  
Keyword(s):  
Metrological Traceability ◽  
Measurement Procedure ◽  
Medical Laboratory ◽  
Clinical Samples ◽  
End User ◽  
Worst Case ◽  
Iso 15189 ◽  
Value Assignment ◽  
Traceability Chain ◽  
Medical Laboratories

Abstract ISO15189:2012 requires medical laboratories to document metrological traceability of their results. While the ISO17511:2003 standard on metrological traceability in laboratory medicine requires the use of the highest available level in the traceability chain, it recognizes that for many measurands there is no reference above the manufacturer’s selected measurement procedure and the manufacturer’s working calibrator. Some immunoassays, although they intend to measure the same quantity and may even refer to the same reference material, unfortunately produce different results because of differences in analytical selectivity as manufacturers select different epitopes and antibodies for the same analyte. In other cases, the cause is the use of reference materials, which are not commutable. The uncertainty associated with the result is another important aspect in metrological traceability implementation. As the measurement uncertainty on the clinical samples is influenced by the uncertainty of all steps higher in the traceability chain, laboratories should be provided with adequate and appropriate information on the uncertainty of the value assignment to the commercial calibrators that they use. Although the between-lot variation in value assignment will manifest itself as part of the long-term imprecision as estimated by the end-user, information on worst-case to be expected lot-lot variation has to be communicated to the end-user by the IVD provider. When laboratories use ancillary equipment that potentially could have a critical contribution to the reported results, such equipment needs verification of its proper calibration and criticality to the result uncertainty could be assessed by an approach based on risk analysis, which is a key element of ISO15189:2012 anyway. This paper discusses how the requirement for metrological traceability as stated in ISO15189 should be met by the medical laboratory and how this should be assessed by accreditation bodies.

scholarly journals Step-by-step control of target efficiency indices of the control and measuring equipment stock applied in construction and housing and communal services

2018 ◽  
Vol 170 ◽  
pp. 01010 ◽  
Author(s):  
Rustam Khayrullin ◽  
Pavel Ivanov
Keyword(s):  
Mathematical Model ◽  
Finite Difference ◽  
Measuring Equipment ◽  
Technical Condition ◽  
Measuring Instruments ◽  
Finite Difference Equations ◽  
Target Values ◽  
The Mathematical Model ◽  
Step Control ◽  
Different Levels

The mathematical model is considered for the formation and implementation of development strategies of the stock of control and measuring instruments (CMI) applied in construction and housing and communal services(HCS), and step-by-step control of efficiency target values of the stock. The model is based on a system of finite - difference equations describing the change of number of the CMI samples with different levels of technical perfection and technical condition at each planning interval. The model allows calculating the required number of CMI for procurement and repairs in the various groups for provide target values of efficiency indices at each planning interval. Controller is number of modern CMI samples for procurement and number of modern and obsolete faulty CMI samples for the repairs. The results of calculations are presented.

scholarly journals The problem of improving the quality of seriously issued certified reference materials of the composition of gas mixtures

2019 ◽  
Vol 15 (3) ◽  
pp. 5-13
Author(s):  
L. A. Konopelko ◽  
A. V. Kolobova ◽  
O. V. Fatina
Keyword(s):  
Reference Material ◽  
Reference Materials ◽  
Certified Reference Materials ◽  
Metrological Traceability ◽  
Gas Mixtures ◽  
Measuring Instruments ◽  
Expanded Uncertainty ◽  
Iso Guide 35 ◽  
The Russian Federation

Currently, in the Russian Federation, the metrological traceability of certified reference materials of the composition of gas mixtures in cylinders under pressure produced by manufacturers of certified reference materials is carried out in accordance with GOST 8.578-2014. Considering that certified reference materials of the composition of gas mixtures in cylinders under pressure are used for testing to approye the type of measuring instruments, verification, calibration, and graduation of gas-analytical measuring instruments used to control explosive gases and vapors, harmful components in the atmospheric air and the air of the working area, emissions from vehicles and enterprises, to control technological processes, the quality of hydrocarbon products, etc., the issue of ensuring the quality of seriously produced certified reference materials (about 100.000 cylinders with gas mixtures per year) is important. To ensure the quality of certified reference materials of gas mixtures in cylinders under pressure, mass-produced by manufacturers of certified reference materials, we offer the following actions:– manufacturers of certified reference materials’ passing of mandatory accreditation for compliance with the requirements of GOST ISO Guide 34–2014 and GOST ISO Guide 35–2015;– manufacturers of certified reference materials’ constant participation in the proficiency testing programs through interlaboratory tests;– actualizing and refining the existing set of standards defining the requirements for the entire life cycle of a certified reference material of a gas mixture in a cylinder under pressure;– improving the method of certification of a reference material by calculating the value of the expanded uncertainty of the reference material and the introducting a new coefficient «technological reserve».

Standardization of 18F and its use for the Romanian PET metrological traceability chain assurance

2014 ◽  
Vol 87 ◽  
pp. 14-18 ◽  
Author(s):  
M. Sahagia ◽  
R. Ioan ◽  
A. Luca ◽  
A. Antohe ◽  
C. Ivan ◽  
...  
Keyword(s):  
Metrological Traceability ◽  
Traceability Chain

Traceability in laboratory medicine: a global driver for accurate results for patient care

2017 ◽  
Vol 55 (8) ◽  
pp. 1100-1108 ◽  
Author(s):  
Graham H. Beastall ◽  
Nannette Brouwer ◽  
Silvia Quiroga ◽  
Gary L. Myers
Keyword(s):  
Reference Materials ◽  
Action Plan ◽  
Metrological Traceability ◽  
Laboratory Medicine ◽  
Geographical Differences ◽  
Traceability Chain ◽  
Stakeholder Groups ◽  
Universal Approach ◽  
Global Coordination ◽  
International Experts

AbstractLaboratory medicine results influence a high percentage of all clinical decisions. Globalization requires that laboratory medicine results should be transferable between methods in the interests of patient safety. International collaboration is necessary to deliver this requirement. That collaboration should be based on traceability in laboratory medicine and the adoption of higher order international commutable reference materials and measurement procedures. Application of the metrological traceability chain facilitates a universal approach. The measurement of serum cholesterol and blood HbA1cserve as examples of the process of method standardization where an impact on clinical outcomes is demonstrable. The measurement of plasma parathyroid hormone and blood HbA2 serve as examples where the current between-method variability is compromising patient management and method standardization and/or harmonization is required. Challenges to the widespread adoption of traceability in laboratory medicine include the availability of reference materials and methods, geographical differences, the use of variable units, complex analytes and limited global coordination. The global collaboration requires the involvement of several different stakeholder groups ranging from international experts to laboratory medicine specialists in routine clinical laboratories. A coordinated action plan is presented with actions attributable to each of these stakeholder groups.

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