The State special primary acceleration measurement standard for gravimetry (GET 190-2019), its composition, principle of operation and basic metrological characteristics are presented. This standard is on the upper level of reference for free-fall acceleration measurements. Its accuracy and reliability were improved as a result of optimisation of the adjustment procedures for measurement systems and its integration within the upgraded systems, units and modern hardware components. A special attention was given to adjusting the corrections applied to measurement results with respect to procedural, physical and technical limitations. The used investigation methods made it possibled to confirm the measurement range of GET 190-2019 and to determine the contributions of main sources of errors and the total value of these errors. The measurement characteristics and GET 90-2019 were confirmed by the results obtained from measurements of the absolute value of the free fall acceleration at the gravimetrical site “Lomonosov-1” and by their collation with the data of different dates obtained from measurements by high-precision foreign and domestic gravimeters. Topicality of such measurements ensues from the requirements to handle the applied problems that need data on parameters of the Earth gravitational field, to be adequately faced. Geophysics and navigation are the main fields of application for high-precision measurements in this field.

A review of the experimental results achieved in the process of atomic fountain clocks construction at “VNIIFTRI” is presented. A possibility of the application of achieved results to the development of a sensitive interferometer (gravimeter) based on cold rubidium atoms is analyzed. The relevance of the study is in the estimation of perspective of interferometer (gravimeter) based on cold atoms for absolute measurements of local free-falling constant development. Physical fundamentals of atomic gravimeter’s operation are described. A comparison between atomic gravimeter and atomic quantum frequency standard based on cold atoms is done. Engineering solutions, that are necessary for building atomic gravimeter with required sensitivity of free-falling acceleration measurement are suggested. In order to build a gravimeter with a sensitivity reaching 1 μGal/Hz1/2 the estimations of laser phase noise, residual gas pressure in vacuum system and magnetic shielding system’s parameters are made.

The problem of inadequacy of mathematical models of measurement objects is considered in connection with the problem of “definitional uncertainty of measurement” and the need for risk management in accordance with GOST ISO/IEC 17025-2019 “General requirements for the competence of testing and calibration laboratories”. The prehistory of the problem is described: from the formation of moment and compositional approaches to estimating accuracy to the introduction of a special term “inadequacy error for mathematical model of measurement object”. The negative impact of hopelessness of conceptual and terminological transformations in metrology and critical contradiction of the applicability estimates for “statistical methods” of GOST R ISO/IEC 31010-2011 “Risk management – Risk assessment techniques” and “Guide to the expression of uncertainty in measurement” is noted. It is shown that taking into account the inadequacy of probabilistic models in risk calculations is a necessary condition for results reliability.

When choosing the optimal number of sampling intervals of the range of values of a one-dimensional random variable, it is established that the functional of the square of the probability density is a constant. The values of the constant are independent of the probability density parameters. The functional dependencies of the studied constant on the coefficient of antikurtosis of the distribution law of a random variable are determined. The analysis of the established dependences for families of lognormal probability densities, Student's distribution laws and families of probability densities with Gauss distribution is carried out. Based on the results obtained, a generalized model is formed between the studied constant and the antikurtosis coefficient. The generalized model does not depend on the type of probability density, but is determined by the estimation of the antikurtosis coefficient. On this basis, we develop a method for estimating the integral of the square of the probability density, which involves the following actions. The random variable interval and the antikurtosis coefficient are estimated from the initial sample. At known values of these estimates, the integral of the square of the probability density is calculated. The effectiveness of the proposed method is confirmed by the results of computational experiments. The conditions of the computational experiment differ significantly from the information used in the synthesis of models of the dependence between the studied constant and the antikurtosis coefficient. The conditions of competence of the method of estimating the probability density square integral from the antikurtosis coefficient are established using the proposed models of the dependence of the studied constant on the conditions of the computational experiment.

The Raman lidar measurements accuracy of hydrofluoride molecules in the atmospheric boundary layer has been estimated in the work at the concentration level of 10¹⁴ сm^–3 and higher in the height range up to 1,5 km in the synchronous photon counting mode. It is received that it can measure the studied molecules concentration at the level of 1,5∙10¹⁴ сm^–3 with the concentration measurement relative error lesser than 25 % at the 405 nm wavelength and the ranging distance up to 500 m by such a lidar.

A technique for calculating the flowrate of cryogenic two-phase flows in separationless flowmeters based on a venturi is proposed. The technique takes into account the equation of state of the two-phase medium, that is changes in density, mass vapour quality and temperature of cryogens two-phase flows against pressure in the venturi. It is shown that without an accounting of the flow parameters evolution, an additional flowrate error appears and therefore it is impossible to correctly determine the sensitivity and measurement range of the flowmeter. The most optimal measurement range of the pressure drop is chosen as well as a method of the flowrate measuring by the temperature difference across the venturi is proposed. The problem of determining the flowrate of two-phase cryogenic flows is topical for accelerator, aerospace and gas-transport engineering.

The paper presents an alternative approach to metrological support and assessment of the technical condition of rolling bearings in operation. The analysis of existing approaches, including methods of vibration diagnostics, envelope analysis, wavelet analysis, etc. Considers the possibility of applying a phase-chronometric method for support on the basis of neurodiagnostics bearing life cycle on the basis of the unified format of measurement information. The possibility of diagnosing a rolling bearing when analyzing measurement information from the shaft and separator was evaluated.

The issues of the use of linear measuring devices for measuring temperature are considered. A method for measuring temperature by resistive temperature sensors based on a modification of the zero method is described. This modification ensures the invariance of the meter to changes in the gain of the measuring path. Zero balance in the measuring path is automatically supported by the synchronous execution of pulse-amplitude and pulse-width modulation and using a tracking circuit for adjusting the width of the latitudinal signal. When reaching zero balance, the pulse width of the latitude modulation control is connected linearly with the resistance of the temperature sensor. The errors of temperature measurements by the modified zero method are considered. The calibration of the manufactured digital thermometer with a miniature resistive temperature sensor made of platinum is described. The proposed modification of the zero measurement method can be used to create devices containing a sensor with a sensitive element – electrical resistance, changing under the influence of a non-electric quantity.

The issues of introducing broadband technologies in civil and special purpose radar systems are considered. The popularity of these technologies for solving a number of practical problems determines the relevance of research related to a detailed analysis of long-range portraits of observed objects at a new qualitative level. The influence of the systematic error of the measuring channel on the reliability of the identification of the geometric shape of the local reflectors of the observation object using the results of broadband radar sounding is studied. The created broadband radar measuring channel with linear frequency modulation of the signal based on the method of generalized heterodyning is described. A technique is proposed for compensating systematic measurement errors for a channel of a given type using calibration spheres. The systematic error in measuring the frequency characteristics of the sphere is estimated, and an error indicator for estimating the frequency characteristics of objects is proposed. The dependence of the statistical indicators of the identification results of the geometric shape of local reflectors on the specified indicator is given. The possibility of identifying the geometric shape of local reflectors of objects by the parameters of their frequency characteristics has been experimentally confirmed. The results can be used to assess the reliability of identifying the geometric shape of local reflectors at the stage of calibration of the measuring channel, as well as to decide on the feasibility of implementing algorithms for identifying the geometric shape of local reflectors on an existing radar.

The dielectric properties of the erythrocyte were studied. Experimental methods and results of measuring the dielectric properties of individual human erythrocyte are presented. The method is theoretically justified. It is established that values of the complex permittivity of the erythrocyte, capacitance, tangent of dielectric losses remains almost constant despite significant changes in conductivity, the content of NaCl of the cell suspension. These values reflect the stability of the studied parameters of erythrocytes under conditions of changes within a wide range of the environment in which the cells are located. Complex cell permittivity and cell dielectric loss tangent are promising parameters for objective diagnostics of human diseases. The introduction of measurements of cell permittivity and cell dielectric loss tangent into medical practice will probably allow us to characterize the process of individual cell self-regulation in more detail.

The issues of using of information and measurement systems based on processing of digital images of microscopic preparations for solving large-scale tasks of automating the diagnosis of acute leukemia are considered. The high density of leukocyte cells in the preparation (hypercellularity) is a feature of microscopic images of bone marrow preparations. It causes the proximity of cells to each other and their contact with the formation of conglomerates. Measuring of the characteristics of bone marrow cells in such conditions leads to unacceptable errors (more than 50%). The work is devoted to segmentation of contiguous cells in images of bone marrow preparations. A method of cell separation during white blood cell segmentation on images of bone marrow preparations under conditions of hypercellularity of the preparation has been developed. The peculiarity of the proposed method is the use of an approach to segmentation of cell images based on the watershed method with markers. Key stages of the method: the formation of initial markers and builds the lines of watershed, a threshold binarization, shading inside the outline. The parameters of the separation of contiguous cells are determined. The experiment confirmed the effectiveness of the proposed method. The relative segmentation error was 5 %. The use of the proposed method in information and measurement systems of computer microscopy for automated analysis of bone marrow preparations will help to improve the accuracy of diagnosis of acute leukemia.