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Grigoryeva I.A.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Khlevnoy B.B.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Solodilov M.V.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI
International Journal of Thermophysics | Year: 2017

Reproducibility of the tungsten carbide–carbon peritectic (WC–C) fixed point (3021 K) was investigated by comparing six WC–C blackbody-type cells with each other. All the cells were built at VNIIOFI and had the same design with a cell outer diameter of 24 mm and a cavity opening diameter of 3 mm. Four cells were built using tungsten powder supplied by Alfa Aesar, while the other two cells used powder from Zhuzhou KETE (China). The nominal purity of both suppliers was 99.999 %. All the cells were compared in the same furnace. A reference cell in the second furnace was used for monitoring the stability of a radiation thermometer. Melting temperatures (given by the point of inflection) of all six cells agreed within ±45 mK. The reproducibility, as a standard deviation of the measured temperatures, can be estimated as 35 mK. The Zhuzhou KETE cells showed a slightly lower temperature than the Alfa Aesar cells: by 32 mK on average, which is comparable with repeatability of the measurements. © 2017, Springer Science+Business Media New York.


Kanzyuba M.V.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Berlizov A.B.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Krutikov V.N.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Lebedev V.B.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Feldman G.G.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2017

The setup under development is intended to serve as the Russian National Primary Special Standard for Laser Pulse Duration in the range from 10 to 1000 ps. The core components of the standard are a streak camera with picosecond temporal resolution and a Fabry-Pérot etalon illuminated by femtosecond laser pulses. The etalon defines a time interval which is used to calibrate the temporal scale of the streak camera. The standard includes a picosecond laser pulse generator for reproduction and transfer of the unit of laser pulse duration to another measuring instrument or secondary standard. Described are the principles of operation, the construction of the standard, and the results of preliminary experiments to determine its metrological properties. © 2017 SPIE.


Sadli M.,Laboratoire Communications Of Metrologie Lne Cnam | Bloembergen P.,Japan National Institute of Advanced Industrial Science and Technology | Bloembergen P.,China Institute of Metrology | Khlevnoy B.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | And 3 more authors.
International Journal of Thermophysics | Year: 2011

For high-temperature fixed points to be accepted as temperature references, it is of prime importance that their long-term stability is demonstrated. This evaluation is part of the CCT-WG5 high-temperature research project (Machin et al. in Int. J. Thermophys. 28, 1976 2007) devoted to a comprehensive evaluation of three high-temperature fixed points: Co-C (1324 °C), Pt-C (1738 °C), and Re-C (2474 °C). The assessment of the long-term stability, as well as the robustness of the cells, is examined in the first workpackage of this project. Four cells for each of the eutectic points have been constructed by NMIJ (4 Co-C, 2 Pt-C, and 4 Re-C) and NPL (2 Pt-C), and stability tests have subsequently been performed by NMIJ (Co-C), NIM (Pt-C), and VNIIOFI (Re-C). These tests consisted of ageing one cell among the set of four, for a period of 50 h around the melting temperature. For each of the three eutectic points, before and after ageing, the aged cell was compared to one of the three cells so that any drift due to ageing could be determined. The aged Co-C, Pt-C, and Re-C cells showed no significant damage and demonstrated highly repeatable melting plateaus. In this paper, after a short description of the cells and ageing process (described more completely elsewhere (Sadli et al. in Acta Metrol. Sinica 29, 59, 2008)), the results for the three fixed points are presented and discussed. © 2011 Springer Science+Business Media, LLC.


PubMed | Japan National Institute of Advanced Industrial Science and Technology, Australian National Measurement Institute, National Institute for Standards of Egypt, U.S. National Institute of Standards and Technology and 9 more.
Type: Journal Article | Journal: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences | Year: 2016

The thermodynamic temperature of the point of inflection of the melting transition of Re-C, Pt-C and Co-C eutectics has been determined to be 2747.840.35 K, 2011.430.18K and 1597.390.13K, respectively, and the thermodynamic temperature of the freezing transition of Cu has been determined to be 1357.800.08K, where the symbol represents 95% coverage. These results are the best consensus estimates obtained from measurements made using various spectroradiometric primary thermometry techniques by nine different national metrology institutes. The good agreement between the institutes suggests that spectroradiometric thermometry techniques are sufficiently mature (at least in those institutes) to allow the direct realization of thermodynamic temperature above 1234K (rather than the use of a temperature scale) and that metal-carbon eutectics can be used as high-temperature fixed points for thermodynamic temperature dissemination. The results directly support the developing mise en pratique for the definition of the kelvin to include direct measurement of thermodynamic temperature.


Svetlichny A.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Kravtsov V.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Kuck S.,Physikalisch - Technische Bundesanstalt | Hofer H.,Physikalisch - Technische Bundesanstalt | Galygo A.,Republican Unitary Enterprise Belarussian State Institute of Metrology
Metrologia | Year: 2014

PTB, BelGIM and VNIIOFI conducted a supplementary comparison on the fiber optic power responsivity at 1308.9 nm and 1548.8 nm. The aim of this comparison is to examine the equivalence of the fiber optic power responsivity among participating laboratories and to provide supporting evidence for associated CMC claims in BIPM KCDB.


Kravtsov V.Ye.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Krutikov V.N.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Tikhomirov S.V.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI
XXI IMEKO World Congress "Measurement in Research and Industry" | Year: 2015

The results of design of state primary and working standards for fibre-optical systems parameters-average power, attenuation, fibre length, wavelength, chromatic and polarization mode dispersion, and also calibration chains for units transferring are described. Principles, contents and parameters of approved standards and calibration chains for units transferring traceability are considered.


Khlevnoy B.B.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Grigoryeva I.A.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI
International Journal of Thermophysics | Year: 2014

The tungsten carbide–carbon peritectic (WC-C) melting transition is an attractive high-temperature fixed point with a temperature of 2747.5◦C. Earlier investigations showed high repeatability, small melting range, low sensitivity to impurities, and robustness of WC-C that makes it a prospective candidate for the highest fixed point of the temperature scale. This paper presents further study of the fixed point, namely the investigation of the long-term stability of the WC-C melting temperature. For this purpose, a new WC-C cell of the blackbody type was built using tungsten powder of 99.999 % purity. The stability of the cell was investigated during the cell aging for 50 h at the cell working temperature that tooks 140 melting/freezing cycles. The method of investigation was based on the comparison of the WC-C tested cell with a reference Re-C fixed-point cell that reduces an influence of the probable instability of a radiation thermometer. It was shown that after the aging period, the deviation of the WC-C cell melting temperature was −0.12◦Cwith an uncertainty of 0.14◦C(k=2). © 2014, Springer Science+Business Media New York.


Khlevnoy B.B.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Grigoryeva I.A.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Otryaskin D.A.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI
Metrologia | Year: 2012

Three cells of the WC-C peritectic fixed point with a temperature of about 3021K were built and investigated. Two different sources of tungsten with nominal purities of 5N and 3N were used, and two different filling techniques were applied. There was no difference in plateau shapes between the cells. The 3N purity cell showed a small difference (0.22K) in the melting temperature from the 5N cell, which indicates significant purification of initially contaminated tungsten. The typical melting range and repeatability of the observed peritectic melting plateaux were 100mK and 15mK, respectively. The melting point was stable and reproducible within 25mK per two weeks. T 90 temperature of the WC-C melting point was found to be (2747.6 ± 1.1)°C (k = 2). The observed freezing plateaux were flat and repeatable within 50mK and 15mK, respectively. The WC 1-x-WC eutectic transition showed a melting temperature about 29K lower than the peritectic one with a repeatability of about 0.2K. The problem of deep supercooling is discussed and a method for its solution is shown and tested. © 2012 BIPM & IOP Publishing Ltd.


Prokhorov A.,Virial International LLC | Sapritsky V.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Khlevnoy B.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Gavrilov V.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI
International Journal of Thermophysics | Year: 2015

Presently, absolute radiometry is the main method of thermodynamic temperature determination above the silver point. The importance of such measurements has increased, as a large international project is underway aimed at assigning thermodynamic temperatures to high-temperature fixed points (HTFPs). All participants are using filter radiometers calibrated against an absolute cryogenic radiometer which, therefore, will be the basis of the provided thermodynamic temperatures of the fixed points. However, such a unified approach may lead to systematic errors (if any) common to all participants. There are methods, providing an alternative to absolute radiometry, which allow the determination of blackbody thermodynamic temperatures using relative measurements. Alternative methods, even if they have lower accuracy than absolute radiometry, could disclose some possible unrecognized systematic errors, or, on the contrary, could confirm the results obtained using absolute radiometry and increase confidence of the thermodynamic temperature determination. One such method, known as the method of ratios (i.e., double wavelength technique), is based on measuring the ratios of fluxes emitted by a blackbody in separate spectral ranges at two temperatures. This approach has been developed at VNIIOFI, but its realization met serious technical difficulties. Modern sensors with improved sensitivity and stability, extremely reproducible HTFP blackbodies, and significant progress in computational methods and computer performance provide a new chance to realize this approach with sufficient accuracy. Another method is based on comparing the ratio of fluxes measured at two wavelengths for a high-temperature blackbody with that measured for synchrotron radiation. This article overviews possibilities of the alternative methods for determination of blackbody thermodynamic temperatures by means of relative radiometry to attract attention of the thermometry and radiometry communities to the importance of international cooperation for realization of these methods. © 2015, Springer Science+Business Media New York.


Ogarev S.A.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Khlevnoy B.B.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Samoylov M.L.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI | Puzanov A.V.,All Russian Research Institute for Optical and Physical Measurements VNIIOFI
AIP Conference Proceedings | Year: 2013

The cavity-type high temperature blackbody (HTBB) models of BB3200/3500 series are the most spread among metrological institutes worldwide as sources for radiometry and radiation thermometry, due to their ultra high working temperatures, high emissivity and stability. The materials of radiating cavities are graphite, pyrolytic graphite (PG) and their combination. The paper describes BB2000/40 blackbody with graphite-tube cavity that was developed for calibration of radiation thermometers at SCEI (Singapore). The peculiarity of BB2000/40 is a possibility to use it, besides calibration of pyrometers, as an instrument for thermocouples calibration. Operating within the temperature range from 900 °C to 2000 °C, the blackbody has a wide cavity opening of 40 mm. Emissivity of the cavity, with PG heater rings replaced partly by graphite elements, was estimated as 0.998 ± 0.0015 in the spectral range from 350 nm to 2000 nm. The uniformity along the cavity axis, accounting for 10 °C, was measured using a B-type thermocouple at 1500 °C. The BB2000/40, if necessary, can be easily modified, by replacing the graphite radiator with a set of PG rings, to be able to reach temperatures as high as 3200 °C. The HTBB utilizes an optical feedback system which allows temperature stabilization within 0.1 °C. This rear-view feedback allows the whole HTBB aperture to be used for measurements. © 2013 AIP Publishing LLC.

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