One of the key parts of laser system of atomic gravimeter based on cold atoms is investigated. In order to construct optical system of atomic gravimeter the laser offset frequency stabilization is needed. Method for frequencydoubled fiber laser’s offset frequency stabilization is suggested and developed. This method is based on modulation transfer spectroscopy and the usage of fiber electro-optical modulator. The experimental scheme of this method is described. The error signals for offset frequency stabilization of frequency-doubled fiber laser are obtained. In order to maximize error signal’s amplitude, experimental parameters such as cell’s temperature, pump and probe beam intensities and electrooptical modulators signal amplitudes are optimized. The influence of polarization on error signal’s amplitude is investigated. It is shown that circular polarization allows to achieve error signal with higher amplitude. The achieved results can be applied to the construction of quantum gravimeter, quantum frequency standards and to the laser cooling experiments.

The standard air flow velocity measurement procedure has been developed in order to unify and standardize the measuring instruments used and data processing algorithms, reduce the development time and certify such standard methods. Sources of error in indirect measurements of air flow velocity in the range 3–105 m/s are investigated. The sources of instrumental error of indirect measurements are analyzed – pressure sensors with digital and analog output signals, pitot tube, temperature and relative air humidity sensors, atmospheric pressure sensors. It is shown that the greatest contribution to the instrumental error is made by measuring the pressure difference and atmospheric pressure. The errors of method, which depends on the measurement model, is considered. A new mathematical model of measurements is proposed, which includes optimal expressions for determining the density of moist air and corrections for compressibility and allows to reduce the methodological error, and requirements for the metrological characteristics of the measuring instruments used are developed, ensuring that the total error of indirect measurements of the flow velocity complies with the allowable limits of ±0,2 m/s. Recommendations are given on the use of measuring instruments and algorithms for processing measurement results, which make it possible to reduce the measurement error by 39 % and develop a standard air flow velocity measurement procedure. The standard procedure is relevant for aviation industry enterprises, where the air flow rate is measured by the pneumometric method.

The problem of cleaning from rough measurements (outliers) of time series of noisy data received from measuring devices is considered. Solving this problem is necessary to improve the accuracy of modern measuring equipment with the latest mathematical software. To minimize the amount of rejected data, the author of this article has previously formulated a problem of finding the optimal solution and proposed a robust algorithm to solve it. The resulting solution is an approximation to the optimal solution and does not always provide the desired minimization. An improved method of cleaning data from outlies is proposed, based on the search for the optimal solution with a minimum number of rejected measurement data. To implement the method, a probleb is set in which an unknown average of the original number series is considered as a parameter to be determined. An algorithm has been proposed too, which makes it possible guaranteed to find the optimal solution in no more than N steps, on each of which the order of N arithmetic operations is required, where N is the number of initial measurement data. The improved method can be used to automatically detect and eliminate outliers from time series of measuring data at the stage of their preliminary processing in information and measuring systems as well as in solving scientific, applied, managerial and other problems in various fields of human activity.

Test objects of various types are used when creating and using video measuring systems which are part of the robots` technical vision, television sights, triangulation measuring systems, as well as 3D scanners. At the same time, an individual test object is developed for each type of device. This paper considers the possibility of development and construction of test objects for calibration (verification) of 2D and 3D video measuring systems, which are used to measure the geometric parameters of twodimensional (2D) and three-dimensional (3D) objects, respectively. We propose to use a measure based on a liquid crystal monitor to calibrate 2D systems. The calibration of such measure is based on the use of a high-precision displacement measurement devices. They are a laser interferometer and subpixel image resolution algorithms. The measure corresponds to the standard of the 3rd category according to the State verification scheme for measuring instruments of length in the range of 1·10^–9–100 m and wavelengths in the range of 0.2–50 microns. The measure can be used to measure the modulation transfer function (MTF) of a video system and the point spread function (PSF). We also propose to use gauge block and move it in space according to the specific program using a translator and an external linear encoder. We introduce the technical specifications of the developed measures that can be used as working standards for calibration (verification) of a wide class of video measuring systems.

This research describes the main systems and nodes of the watt balance experimental model created at the D. I. Mendeleev Institute for Metrology. It presents the results of studies of metrological characteristics of the watt balance model arrangement component part that operate on the principle of electromagnetic force compensation with a monolithic weight converter and a lower suspension. The studies were conducted with the use of standards traceable to the state primary standard of the unit of mass – kilogram. The research provides the information on the joint efforts of national metrological institutes aimed at the gradual spread of the unit of mass traceable to the fundamental physical constant – Planck's constant, the fixation of the numerical value of which was adopted at the 26th General Conference on Weights and Measures in Paris on May 20, 2019. Here the necessity of carrying out work to maintain the equivalence of the national standard of the unit of mass to the best national standards of other countries is reflected, because it is also the required factor for international recognition of the measuring capabilities of the metrological institutes of Russian Federation. The findings of the metrological characteristics of the watt balance experimental model studies showed potential possibility of using the design solutions applied in this experimental model for creating the measurement standard in the Russian Federation to implement a new definition of the kilogram.

Thermal diffusivity a and thermal conductivity λ are important for many building, structural and functional material applications. They determine the intensity of heat transfer, the quality of thermal insulation, the rate of heating / cooling, reaching a stationary mode, and the efficiency of power equipment. In laser technology, the radiation strength of the optical components of the system depends upon them, and in laser technologies with material removal they determine the speed and quality of processing. Most methods for measuring a and λ in solid materials require cutting out samples of a certain geometry, which makes them unsuitable for testing finished products. The paper proposes and describes an express method for determining a and λ in translucent materials, which does not require cutting a sample from a controlled object. It consists in the analysis of a non-stationary temperature field on the surface of the test object using a high-speed thermal imaging camera. The unsteady heating spot was created by a focused laser beam. It was switched on abruptly and operated in the mode of continuous irradiation with a constant intensity during the entire time of measurements. Heat propagated from this spot to the periphery, creating a non-stationary temperature field containing information about a and λ. The a value was extracted from the primary data using original algorithms and software. A thermal imager, as a recorder of a dynamic temperature field, provides a number of advantages – non-contact, high speed and a large amount of information (each of the many hundreds of thousands of pixels of a professional thermal imager matrix is a temperature sensor in a small surface area). Measurements of a and λ in semitransparent materials of laser optics have their own specifics. The low radiation absorption coefficient and the possible curvature of the surface (for example, in lenses) require special measures, which are described in the article. Due to the large amount of information contained in the dynamic patterns of the thermal field and the possibility of averaging over a large data array, the RMS of the thermal diffusivity measurement does not exceed 2 %.

The wide use of small-sized wearable electronic devices in various practical human activities makes it relevant to measure the proportion of electromagnetic energy absorbed by the human body. One of the most important parameters that determines it is the specific absorption rate. In this article we propose a method for determining this coefficient for a liquid phantom, with the use of computer simulation and experimental measurement of the microstrip patch antenna parameters.

The antenna is located on an elliptical cylinder and operates in the medical body area network. The method is based on measuring the rise in temperature of the liquid phantom exposed to electromagnetic waves generated by a microstrip antenna over a given time. Homogeneous liquid phantom was created by changing the percentage of salt and sugar in 250 g of water, skin phantom – by changing the percentage of water in 200 g of glycerol. The proposed specific absorption rate measurement method eliminates the need to purchase an expensive set of dielectric probes, which demonstrates its cost-effectiveness. The obtained results of experimental measurements are in good agreement with the results of the performed computer simulation.

The ways of reducing the error of measurement methods of frequency deviation and expanding the measurement ranges of frequency deviation are considered. The possibilities of reducing the error of the electronic counting frequency meter method using digital signal processing algorithms are investigated. Digital signal processing algorithms are implemented in the software developed by the authors of a modern spectrum analyzer. The algorithm of digital signal processing of the spectrum analyzer is described. Using a mathematical model embedded in the calculation algorithm of the developed software, the measurement error of frequency deviation is estimated. The possibility of using the electronic counting frequency meter method with the help of digital signal processing algorithms of the spectrum analyzer has been experimentally investigated. The sources of error of the classical method of electronic counting frequency meter and possible ways of their elimination are considered. Comparisons of the proposed implementation of the electronic counting frequency meter method with the classical method, which is implemented in the State Primary Standard of the unit of frequency deviation GET 166-2020, are carried out. The proposed implementation of the method has expanded the measurement range of frequency deviation towards small values in comparison with the classical method of electronic counting frequency meter. Limitations and prospects of application of the investigated method in reference means of measuring frequency deviation based on analog-to-digital converters are considered.

A brief overview of analysis methods and analytical identification parameters of components of complex mixtures is given. The parameters of identification of substances in the chromatographic analysis of complex multicomponent mixtures – linear retention indices – are considered, and it is shown that to ensure the necessary level of reliability of the analysis results, it is necessary to assess the uncertainty of measuring these indices. A general equation for determining the variance of the result of indirect measurements of linear retention indices is obtained. For the case of the analysis of mixtures containing both assays and n-alkanes, and mixtures with a separate content of these components, its particular formulations are derived from this general equation. A formula for determining the effective number of degrees of freedom of standard uncertainty is presented, taking into account the correlation of input variables in the measurement equation. Mathematical expressions are obtained for calculating the extended uncertainties of estimating linear retention indices, which take into account correlations of retention times of neighboring chromatographic peaks. By methods of interval mathematics, an upper estimate of the standard uncertainty of linear retention indices in the case of the joint presence of analytes and n-alkanes in the analyzed mixture was obtained and its significant decrease in comparison with the specified uncertainty in the analysis of mixtures with a separate content of these components was shown. The correspondence of theoretical and experimental results has been established. The results obtained can be used to identify the components of the analyzed mixture when standardizing chromatographic analysis techniques.

The problem of the lack of instruments for the operational measurement of the components of the production of gas condensate wells – multiphase flow meters – is considered. Actual problems solved with the use of multiphase flowmeters are described, and the main requirement for these devices is the measurement of the components of a gas condensate flow without separating it into gas and liquid phases using a separator. A method is proposed for determining the volumetric contents of the components of the products of gas condensate and oil and gas condensate wells using a non-separation technique for registering components. The probing of a gas-liquid flow by decimeter radio waves at the moment of flow passing through a microwave resonator is described, and a variant of the design of a non-separation analyzer of volume fractions of gas, condensate and water in the production products of gas condensate wells is proposed. The volume fractions of gas, water, and condensate were determined from the results of measurements of the frequency shift and the quality factor of the resonator. 

At the same time, an acceptable accuracy (less than 5 %) of determining the amount of condensate is provided only at high condensategas ratios (300–1000 cm³/ m³) and low water-gas ratios (30–100 cm³/m³). With an increase in the proportion of water or a decrease in the proportion of condensate, the error in determining the gas-condensate factor becomes unacceptably high (more than 10 %). It is proposed to reduce this error by introducing a bypass line into the flow meter containing a filter for separating the liquid phase and a reference resonator. The reference resonator registers the frequency shift due to the gas phase. The filter is probed with an eight-millimeter radio beam, which reacts to the content of only the water component. The data obtained from the resonator and filter significantly expand the range of recorded condensate-gas and water-gas factors. Possibilities of using the proposed technique: determination of volume fractions in the production products of gas condensate wells; application in multiphase flow meters for gas condensate fields; quality control of separators that separate liquid before further gas supply (when equipment is installed both before the separator and after it). Large bore resonators could be used to control gas-liquid flow through pipelines of large diameters, such as collector pipelines.

Metrological support for the process of molecular genetic identification is provided. An establishment of a nucleotide sequence is the general aim in nucleic acids analysis. A nucleotide sequence of DNA/RNA is the key information which gives an idea of the role and functioning of nucleic acids in living systems, as well as it allows establishing the origin of biological objects during molecular genetic identification. The molecular genetic identification is based on modern methods of research in the sequencing of DNA, which is inherited from generation to next generation of living organisms. DNA sequence comparison in some cases is mandatory to establish the authenticity of biological objects and to determine biological affiliation or kinship with other biological objects. The problems of metrological support of molecular genetic identification by Sanger DNA sequencing using fluorescently labeled reaction terminators and the use of capillary electrophoresis on the example of fish identification are considered. Metrological support of the process includes the use of such definitions as a nucleotide (the nucleic acid monomer), a sequence of nucleotides of nucleic acids. Also, it involves the procedures used in certified methods, a standard sample of a known DNA sequence of an approved type, and a genetic analyzer.

Standard Reference Materials of a fragment of human mitochondrial DNA was developed, approved, entered into the Federal registry. The tests of the domestic genetic analyzer Nanophore 05 were carried out. Two measurement procedures “The measurement methodology the partial nucleotide sequence of the control region of mitochondrial DNA of fish (families Acipenseridae and Polyodontidae) by Sanger sequencing with fluorescently-labeled terminators and using capillary electrophoresis” and “The measurement methodology the nucleotide sequence of the 5’ region of the mitochondrial COI gene of water biological resources by Sanger sequencing with fluorescently-labeled terminators and using capillary electrophoresis” were tested and certified. The results are relevant to research in biological sciences, the food industry, biotechnology, and DNA forensics.