Application of systems thinking to the establishment of metrological traceability chains

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.

On the Calibration of GNSS-Based Vehicle Speed Meters

Thanks to their metrological characteristics (accuracy, dimensions, synchronization capability, easy interfacing, and so on), in the last few years, the GNSS (Global Navigation Satellite System) based speed instruments are often used in a wide field of application. The traceability of the measurement results achieved by the GNSS instrument should be made by means of calibration procedures in compliance with the ISO/IEC 17025 standard and ILAC (International Laboratory Accreditation Cooperation) policy on the traceability of measurement results. In this context, some calibration methodologies have been proposed in the literature or used by some calibration centers. In a speed range from 1 to 300 km/h, an analysis on the suitability of the experimental calibration method (based on a couple of photocells placed on the road at a certain distance) for the GNSS speed measurement systems is presented in this paper. An analysis of the measurement setup has allowed for the recognition of both all the uncertainty contributions and defines the variability range of their values. After the formulation of the relationships between the uncertainty contributions and the total calibration uncertainty due to the calibration method, the sensitivity analysis has been made. The analyzed measurement setup, even if considering a careful choice of both instrumentations and methodologies, is suitable for the calibration of high accuracy GNSS based instruments only considering distances between the photocells sufficiently large and for speed values lower than 200 km/h. In any case, the proposed analysis can be a useful tool to allow for the choices on the measurement setup to reach the desired trade-off between calibration costs and compliance with technical requirements and also the calibration of instrumentation different by GNSS.

Certified Reference Materials and Metrological Traceability for Mycotoxin Analysis

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

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.”

RusAccreditation and International Recognition of the National Accreditation System

The activities of the Federal Accreditation Service including cooperation with international accreditation institutions, i.e., International Laboratory Accreditation Cooperation (ILAC) and the Asia-Pacific Laboratory Accreditation Cooperation (APLAC) are reviewed. Issues regarding implementation of the system of good laboratory practice in the context of cooperation between Russia, Organization for Economic Cooperation and Development (OECD), and Slovak National Accreditation Service are considered. Information about mutual recognition agreements and bilateral arrangements of the Federal Service for Accreditation and national accreditation bodies of the foreign countries are discussed along with the results of the activities of RusAccreditation during the 1st quarter of 2018 and goals for the near future.