Calibration of Diameter Standards (EURAMET.L-K4.2015)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00177016%3A_____%2F21%3AN0000071" target="_blank" >RIV/00177016:_____/21:N0000071 - isvavai.cz</a>

Result on the web

<a href="https://www.bipm.org/documents/20126/45451527/EURAMET.L-K4.2015.pdf/04dc7e78-7dcf-9d97-392a-e764bd7adb20" target="_blank" >https://www.bipm.org/documents/20126/45451527/EURAMET.L-K4.2015.pdf/04dc7e78-7dcf-9d97-392a-e764bd7adb20</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Calibration of Diameter Standards (EURAMET.L-K4.2015)

Original language description

The metrological equivalence of national measurement standards and of calibration certificates issued by national metrology institutes is established by a set of key and supplementary comparisons chosen and organized by the Consultative Committees of the CIPM or by the regional metrology organizations in collaboration with the Consultative Committees. At its meeting in October 2014 , the EURAMET TC for Length , decided upon a key comparison on diameter gauges , named EURAMET.L-K4.2015, with INRIM as the pilot laboratory, following the comparison CCL-K4.2015. The EURAMET comparison was registered in November 2016, the circulation of the artefacts started in November 2016 and completed in February 2018. A goal of the CCL key comparisons for topics in dimensional metrology is to demonstrate the equivalence of routine calibration service s offered by NMIs to clients, as listed in Appendix C of the Mutual Recognition Agreement (MRA). To this end, participants in this comparison agree d to use the same apparatus and methods as routinely applied to client artefacts. Due to the large number of participants, it was decided to have 2 groups in the project. Two sets of diameter gauges of the same type and size were circulated in parallel in the two groups. An ATA Carnet was provided for circulation of the group 2, which includes several NMIs outside Europe. Some delays in circulation occurred in both groups, mainly due to minor changes in schedule, shipping and customs operations. Twelve laboratories from EURAMET participated in group 1, while eleven laboratories from EURAMET and two laboratories from other RMOs participated in group 2. CEM, INRIM and METAS participated in both groups to link them. The comparison followed the guidelines for CIPM key comparisons [1]. Data and results are reported as the first version of the draft B using the document layout principles for previous comparisons [2-3]. The allowance to use parts of this prior work wherever possible is gratefully acknowledged. Twelve laboratories from EURAMET participated in group 1, while eleven laboratories from EURAMET and two laboratories from other RMOs participated in group 2 of this comparison on diameter standards. CEM, INRIM and METAS participated in both groups to link them. The comparison was driven according to Key Comparison Guidelines. Some delays in circulation occurred in both groups, mainly due to minor changes in schedule, shipping and customs operations. Measurements reports have been submitted by all the NMIs and DIs. Unfortunately, EMI (UAE) has withdrawn. No significant drifts due to secular changes of the gauges were observed with most of the gauges, while an apparent change in length outside the k = 2 uncertainty of the pilot laboratory was observed with the two plugs 100 mm, leading to an apparent shrinkage drift of these gauges during the circulation. Some scratches and minor damages were reported during the circulation. The artefacts are of typical geometry and surface finish. Measurements have been carried out with various measuring apparatus and different probing conditions by using spherical or flat tip probes and contact loads from a few milliNewton to the Newton range. The participants were asked to report diameter, roundness and straightness of the gauges. In primis, the KCRV was calculated on a gauge-per-gauge basis as the weighted mean of the submitted results of the diameter, roundness and straightness measurements. If not consistent, the KCRV was recomputed by zero weighting the result with larger En and the process iterated until a consistent Birge ratio was achieved. With group 1, En ≥ 1 gave a number of 6 for diameter and 7 for roundness, while with group 2 a number of 6 for diameter. These numbers are mostly reflected in the comparison with reference values, while it is worth noting that with the plugs 100 mm a decrement of 3 inconsistent results is achieved by introducing an uncertainty contribution related to the apparent change of length of these gauges. In secundis , the KCRV was calculated by linking the two groups according to the mathematics in reference [4]. Results of the linking are calculated for the diameter of all the twin gauges and for the roundness of the twin spheres. When compared to those calculated independently for each group, minor changes of the KCRVs and associated uncertainties are observed from linking the groups. Consistency checks are satisfied for most of the gauges with the exception of the plugs 100 mm, which suffer from an apparent change in length during the circulation. With the linking, En ≥ 1 gave a number of 12 for diameter and 1 for roundness of the sphere. In conclusion, the comparison shows a generally good constancy of results either for diameter, departure from roundness and straightness measurements. DOI 10.1088/0026-1394/58/1A/04004

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

21100 - Other engineering and technologies

Project

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Continuities

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů