Comparisons of National Standards of the Unit of Length in the Field of Measuring the Parameters of Deviation from Flatness of Optical Surfaces Coomet.L-S15

Precision interference measurement of parameters of form optical surfaces are one of the most important type of the measurement in the field of the geometrical values. In countries-participants of this comparisons the special primary standards in this field of measurements take part in reproduction and transmission the unit of length in this field of measurements ensuring high measuring and calibrating capabilities countries in this type of measurement. In this article presents the result of supplementary comparisons COOMET 570/UA-a/12. The result of comparisons allowed to declare to Belarus and Russia, and to confirm to Ukraine their measuring and calibrating capability in database CIPM MRA.

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Improvement of the Russian National Secondary Standard of the Unit of Length Using Latest Ultra-Stable Laser Equipment

Journal of the Russian Universities Radioelectronics ◽

10.32603/1993-8985-2019-22-4-109-114 ◽

2019 ◽

Vol 22 (4) ◽

pp. 109-114

Author(s):

Andrew A. Mosckalev ◽

Ardi Rahman

Keyword(s):

Measurement Uncertainty ◽

Frequency Comb ◽

Uncertainty Budget ◽

National Standards ◽

Secondary Standard ◽

Measuring System ◽

Internal Diameter ◽

Traceability Chain ◽

Unit Of Length ◽

Stable Laser

Introduction. Increasing demands of precise geometry measurements by science and industry cause the necessity of improvement in an associated branch of legal and practical metrology. One of the most significant fields is the measurement of internal dimensions and so the issues with the unit of meter transfer. Now we face the situation when the current accuracies of National standards of different levels in corresponding traceability chain (reference rings measurements) get close to each other. This means that we have to make the standard of upper level more precise. One of the obvious ways is to apply the latest ultra-stable laser locked to a frequency comb.Objective. The objective is to propose possibilities for improvement of the National secondary standard of the unit of length by researching its measuring capabilities to minimize measurement uncertainty.Materials and methods. The calculation of expanded uncertainty of internal diameter measurements by the National secondary standard of the unit of length is performed according to the international document «Guide to the Expression of Uncertainty in Measurement» JCGM 100:2008 approved by BIPM. The secondary standard research results represented in previous reports and publications are also taken into consideration.Results. Detailed uncertainty budget for the proposed measuring system is given as well as graphical data representing the accuracy improvement.Conclusion. Actions for minimization of measurement uncertainty components of the National secondary standard of the unit of length in the field of reference ring internal diameter measurements in combination with state-of-the-art laser interferometer system improve it to the next frontiers of accuracy and precision.

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