The article describes the main shortcomings of the current SI, the planned changes and their implications for implementation and dissemination in various areas of metrology.

An overview over the history of time measurement and development of clocks is presented. The main clock characteristics are described. The idea and the basic principles of atomic clocks are stated.

The article presents the project of Th-229m nuclear clock. The experiments searching for a radiative decay and the detection of the isomer of thorium-229m, as well as indirect experiments to determine the energy of the isomer are described. Potentially promising research methods and experiments for detection of the isomer of thorium-229m are offered. The prospects for frequency standard based on thorium-229m are presented. Other elements for nuclear clock are proposed.

The possibilities and modern trends in the development of the primary measurement standards base of D. I. Mendeleyev Institute for Metrology (VNIIM) in the field of geometric measurements, mechanical measurements and in the areas of related quantities are described.

The functional possibilities of the State primary measurement standard of the magnetic flux density, magnetic flux, magnetic moment and gradient of magnetic flux density units GET 12-2011 were investigated for purposes of transfer of the magnetic flux density unit in the ranges of "low" and "high" magnetic fields, and transfer of a magnetic flux unit to measuring instruments soft magnetic materials parameters.

The article examines The state-of-art and prospects for further improvement of the State primary measurement standard of a unit of temperature in the range from 0 to 3000 °С the GET 34-2007. The main tasks that should be addressed in the process of improving that Measurement Standard are as follows: providing the ability to reproduce the kelvin in the range above 961,78^oС in accordance with its new definition, which may come into force in 2019; improvement the accuracy of Kelvin's reproduction in 1,5-2 times; extension the range of reproduction of the unit of temperature to 3200^oС. The ways of perfection of the GET 34-2007 for realization of the ITC-90 in a range from 273,15 to 1235 K are shown.

The needs of the work on improvement of the State Primary Special Measurement Standard of unit of mass concentration of particles in aerodisperse media GET 164-2003 are substantiated. The structure of the Measurement Standard is reviewed and methods of realization and dissemination of the unit are described, and the main metrological characteristics of the improved Measurement Standard are given. The improved Measurement Standard GET 164-2016 is presented. The comparison of both Measurement Standards was done.

The principles of constructing a multivalued voltage standard N4-21, based on precision properties of the Zener diodes and quantum properties of high-temperature superconductor Josephson junctions, operating at 77 K are discussed. Тhe metrological characteristics of the new voltage standard are presented. It is shown that the relative uncertainty of the output voltages 1 and 10 V is less than 5‧10^-8.

The article analyses the requirements of modern industrial technology to the measurement of the hydrogen concentration in the solid sample. The results of the described experiments show that there are multiple discrepancies in the comparisons of standards from different manufacturers on the market today. One of the most likely sources for this discrepancy is the method of heating and melting the sample in a stream of carrier gas. The conclusion about his unsuitability for the creation of the Metrology system, and to measure the concentrations of hydrogen in structural materials on the level of values and precision required for the safe functioning of modern economies.

We developed a new reference standard of carbon isotope ratio¹³С/¹²С for measurements of δ¹³С_VPDB in CO₂. There is a gas mixture of pure¹²CO₂,¹³CO₂ and N₂. The new reference standard eliminates the need of preparation of existing reference standards when measuring the δ¹³С_VPDB in CO₂. The procedure of preparation and verification of reference standard is described in detail, and their stability is checked. The developed standard samples can be used for verification and calibration of both isotope infrared gas analyzers and isotope mass spectrometers.

This paper introduces the PRISM, a new type of signal processing technology providing a fully recursive, dual output FIR filter. A simulation example demonstrates that PRISM signal processing can be used to autonomously detect, track, and compensate for an undesired frequency component in a frequency-based sensor in real time, i.e. to carry out its self-check and self-correction.

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.