Vol 60, No 12 (2018)
- Year: 2018
- Articles: 14
- URL: https://journals.rcsi.science/0543-1972/issue/view/15337
ON THE 175th ANNIVERSARY OF THE MENDELEEV ALL-RUSSIA RESEARCH INSTITUTE OF METROLOGY (VNIIM)
The Revision of the SI – Towards an International System of Units Based on Defining Constants
Abstract
Following many years of intense investigations, leading to significant progress with the determination of fundamental constants, it is now likely that the General Conference for Weights and Measures (CGPM) will approve revised definitions for the SI base units at its next meeting in November 2018. It is proposed that the definitions for the kilogram, the ampere, the kelvin, and the mole will be based on new physical concepts, whereas the definitions for the second, the meter and the candela will only be reformulated. As a consequence, the units of the revised SI would be derived from a set of seven defining constants. This article describes the principal shortcomings of the present SI, the planned changes and the consequences for the realization and dissemination of units in the different fields of metrology.
Article
Towards a 229Th-Based Nuclear Clock
Abstract
An overview of the current status of the development of a nuclear clock based on the state of lowest known nuclear excitation energy in 229Th is presented. The text is especially written for the interested reader without any particular knowledge in this field of research. It is thus ideal as an introductory reading to get a broad overview of the various different aspects of the field; in addition, it can serve as a guideline for future research. An introductory part is provided, giving a historic context and explaining the fundamental concept of clocks. Finally, potential candidates for nuclear clocks other than 229Th are discussed.
Contemporary State of Primary Standards in the Fields of Measurements of Geometric, Mechanical, and Related Quantities
Abstract
The possibilities and contemporary trends in the development of the base of primary standards of the Mendeleev All-Russia Research Institute of Metrology (VNIIM) in the fields of measurements of geometric, mechanical, and related quantities are described.
Development of the Standards Base in the Field of Measurements of Magnetic Induction and Magnetic Flux
Abstract
The functional capabilities of State Primary Standard GET 12–2011 of the units of magnetic induction, magnetic flux, magnetic moment, and gradient of magnetic induction are investigated for the purpose of expanding the range of measurements in the transmission of the unit of magnetic induction into the area of measurements of strong and weak magnetic fields as well as in the transmission of the unit of magnetic flux by instruments for measuring the parameters of magnetically soft materials.
Redefinition of the Kelvin and Future Improvements in State Primary Standard of the Unit of Temperature in the Range from 0 to 3000°C GET 34–2007
Abstract
The state and prospects for further improvement in State Primary Standard of the unit of temperature in the range from 0 to 3000°C GET 34–2007 are considered. The basic problems that have to be solved in the course of improving GET 34–2007 include providing the ability to reproduce the kelvin in accordance with its new definition (scheduled to come into force in 2019) at a temperature above 961.78°C, increasing the precision of reproducing the kelvin 1.5–2.0-fold, and expanding the range of reproduction of the unit of temperature to 3200°C. Ways of improving GET 34–2007 to implement the 1990 International Temperature Scale (ITS-90) in the range 273.15–1235 K are demonstrated.
State Primary Special Standard of the Unit of Mass Concentration of Particles in Aerodispersed Media, GET 164–2016
Abstract
The need to improve the State Primary Special Standard of the unit of mass concentration of particles in aerodispersed media GET 164–2003 is demonstrated. The structure of the standard is considered, methods of reproduction and transmission of the unit are described, and the basic metrological characteristics of the standard are presented. The improved standard GET 164–2016 is presented. A comparative analysis of the characteristics of the two standards is performed.
The N4-21 Voltage Standard Based on Josephson Junctions of High-Temperature Superconductors
Abstract
The principles for building the multivalued N4-21 voltage standard based on the precision properties of Zener diodes and the quantum mechanical properties of high-temperature superconductor Josephson junctions operating at 77 K are discussed. The metrological characteristics of the new voltage standard are presented. The relative uncertainty in the output voltages of the standard at 1 and 10 V is found to be less than 5·10–8.
New Metrological Support for Measurements of the Concentration of Hydrogen in Solid Samples
Abstract
Specifications for methods of measuring the concentration of hydrogen in solid samples are analyzed. Multiple discrepancies in the results of comparisons of modern standard samples from different manufacturers are found experimentally and the probable source of these discrepancies is the method used to heat and melt samples in a carrier gas flow for the measurements. It is concluded that this method is unsuitable for metrological support of measurements of the concentration of hydrogen in structural materials, since the metrological characteristics of these means of measurement do not meet the requirements for safe operation in the modern economy.
Development of a New Type of Reference Standard for Carbon Isotopic Composition
Abstract
The development of a new type of reference standard for carbon isotopic composition consisting of 12CO2 + 13CO2 and N2 gaseous mixtures in tanks under pressure is discussed. These standards are required for measuring the isotope ratio 13C/12C in gaseous mixtures of CO2. The procedures for preparing and verifying the reference standards are described and their stability is tested. These standard samples can be used for calibrating (testing) isotopic infrared analyzers and mass spectrometers.
An Introduction to Prism Signal Processing Applied to Sensor Validation
Abstract
This paper introduces the Prism, a new type of signal processing block, as a contribution to the challenges of 21st Century metrology. The Prism is a fully recursive, dual output, FIR filter: the computational burden is low and independent of data window length. Prism design is trivial, so that networks of Prisms can be created, whether at design time or autonomously in real time, to carry out a range of metrological tasks. Prism-based trackers can generate sample-by-sample estimates of frequency, phase, and/or amplitude of a sinusoid. A simulation example of sensor validation demonstrates how Prism signal processing can be used to autonomously detect, track, and compensate for an undesired frequency component in a frequency-based sensor.
On the Quantitative Expression of the Accuracy of Laboratory and Industrial Measurements
Abstract
A comparative analysis of approaches and methods for expressing the accuracy of industrial (routine) and laboratory measurements is carried out. Debatable questions of summation of systematic and random errors and use of uncertainty in the system of indicators of measurement accuracy are discussed. The applicability of measurement uncertainty in the quantitative expression of the accuracy of laboratory measurements is substantiated.
Measurement of the Reflectivity of Radiation Absorbent Materials by Pulsed Spectroscopy
Abstract
Results from an experimental study of the reflectivity of radiation adsorbent materials probed by ultrashort electromagnetic radiation are presented. Ultra wide-band pulsed microwave spectroscopic methods are used. Measurements of reflectivity by traditional narrow band and ultra-wide band techniques are compared.
Linear and Angular Measurements
Modernization of Instruments for Measurement of Linear and Angular Displacements on the Foundation of a Precision Extremal Measurement System
Abstract
Modernization of instruments for the measurement of linear and angular displacements with the use of small-period optical measures, multiplicative transducers of scanning compensation guidance interpolators, and a universal signal processing system is considered.