The composition of the State primary standard of units of volumetric activity of radioactive aerosols,  radon, thoron and radon flux density GET 39-2021 is presented. Methods for reproduction and  transmission of volumetric activity units of radioactive aerosols, radon, thoron and radon flux density are described. Possible sources of error are indicated, their quantitative assessment is made, metrological characteristics of GET 39-2021 are given. GET 39-2021 ensures the uniformity of measurements of the volumetric activity of radioactive aerosols, radon, thoron and radon flux density in various fields of activity in the nuclear industry, at enterprises for the production and processing of nuclear raw materials and materials, etc. In the nuclear industry, GET 39-2021 serves to ensure radiation safety of personnel at nuclear facilities and the environment during the creation and commissioning of new generation nuclear reactors.

The composition and characteristics of the State primary special standard of electrical capacity units in the frequency range from 1 to 300 MHz GET 107-2019 are  described. The upper limit of the frequency range of electrical capacitance reproduction has been expanded to 300 MHz due to the development of a new reference installation with an operating frequency of 300 MHz. The principle of operation of the installation and algorithms for processing measurements are considered. The non-excluded relative systematic error of GET 107-2019 is from 5·10^–5 to 1·10^–3 (depending on the operating frequency), the relative standard deviation of the measurement result when reproducing the unit is from 3·10^–6 to 3·10^–4, which exceeds the capabilities of national standards of other countries. An updated State Verification Scheme for measuring electrical capacitance in the frequency range from 1 to 300 MHz has been developed and approved. GET 107-2019 and its subordinate standards and measuring instruments are widely used in micro- and nanoelectronics, radioelectronic industry, instrument engineering, in the development and production of modern materials and devices, in biomedicine.

To increase the computational efficiency of nonparametric regression, a method has been developed for fast selecting the blur coefficients of the kernel functions of nonparametric regression when restoring unambiguous stochastic dependencies. The application of the technique allows to significantly reduce the time spent in the synthesis of nonparametric regression in comparison with the traditional approach. The basis of the proposed methodology is the procedure for estimating the optimal blur coefficients of kernel functions for nonparametric estimation of the joint probability density of a family of dependent random variables with normal distribution laws. The method of selection the blur coefficients of nonparametric estimates of two dimensional probability density and regression of dependent random variables is investigated. The regularities of the influence of parameters of distributions of random variables and errors of their estimation on the efficiency indicators of the developed methodology are established. It is shown that the advantage of the proposed technique over the traditional approach is especially significant at small and large noise levels of the values of the function being restored.

In order to control the quality of assembly and adjustment of engines, acceptance tests have carried out. The conclusion about the quality of the repaired engine depends on the measurement information received during acceptance tests. Therefore, it is important to ensure the accuracy and reliability of the measurement results of the controlled engine parameters. Permissible errors of the main controlled parameters of engines during acceptance tests have set in GOST 18509-88 « Tractor and combine diesel engines. Methods of bench tests», but this document does not contain requirements for the permissible error in measuring engine power. Based on the probability theory, the formula for calculating the power measurement error has derived. Based on the derived formula and taking into account the permissible measurement errors (according to GOST 18509-88), the permissible measurement errors of power of repaired engines of various brands have calculated. A comparative analysis of the calculated value of the permissible error in measuring the power of engines of various brands and the actual error in measuring power during running-in on the stands KI-5274, KI-5540M, KI-5541M, KI-542M, KI-2118A GOSNITI. It had found that the power measurement errors exceed the maximum allowed. To increase the reliability of power control results, recommendations have been developed for calculating acceptance boundaries with an off set relative to the nominal power value. The maximum errors of power measurement of various engine brands and acceptance limits have calculated depending on the required reliability. Application of the method will increase the reliability of control results at the stage of acceptance tests of repaired engines.

The model for managing the process of operation and updating the fleet of measuring equipment, taking into account degradation processes is proposed. The model includes three groups of degradation of measuring equipment. The functional dependence of the stationary availability coefficient on the intervals between verifications, on the relative operational tolerances for the controlled parameters, on the relative measurement errors and other technical and technological parameters of the operation and renewal of the fleet is constructed. The presented model allows us to calculate the optimal (rational) parameters of operation and renewal of the fleet of measuring equipment. The model can be used to classify complex technical systems in order to set requirements for their metrological support.

The use of six-axis coordinate measuring machines “Lapik” for measuring the roughness of complex surfaces has a feature that consists in non-uniform discretization along the coordinate axes. One of the elements of the applied software should be a morphological filtering algorithm that takes into account this specificity. Compared to linear and regression Gaussian filters, morphological filters have a number of advantages. The main ones are the absence of edge effects and the not need to first apply a form filter. The well-known basic discrete algorithm for the morphological filter provides for a constant profile discretization step. Another limitation is related to the error from the discretization of the structural element. This article presents a discrete algorithm that takes into account the indicated features of measurement on coordinate measuring machines. To do this, the primary roughness profile is subjected to piecewise linear interpolation, and the disk structural element is described continuously. This makes it possible to determine the center of the disc with less error during morphological operations. Checking the accuracy of the algorithm on real and model examples showed that the filtering error in measuring the parameters Ra and Rqs about 3 %. The advantage of the developed algorithm is realized with a high unevenness of the initial data. The comparison of the performance of the proposed algorithm with the known ones showed its sufficient efficiency. The calculation time for 10000 points of the roughness profile does not exceed 0.05 sec.

The problem of instability of the results of structural-parametric identification of metrological characteristics of a functional type during calibration and calibration of measuring instruments using various identification criteria with a small number of measurements is described. These characteristics include calibration diagrams, conversion functions, calibration characteristics, error distribution functions, etc. It is shown that the results of solving the problem of identifying metrological characteristics of a functional type are affected by the order of splitting the data of joint measurements into blocks in the cross-observation scheme of the maximum compactness method. The comparison of the criteria of structural identification – the minimum of the average modulus of the inadequacy error and the maximum of the Kappa criterion (probability of agreement) is carried out on the example of the thermometer calibration problem. It is established that if it is impossible to divide the data of joint measurements into equal parts, the kappa criterion has a higher stability of the results. The results can be applied when writing specialized automatic data processing programs for calibration and calibration of measuring instruments, unambiguous identification of metrological characteristics of a functional type according to measurement protocols, for example, when performing certification of measurement methods.

Three-dimensional object geometry measurement systems based on the phase triangulation and binary Grey codes methods were considered. Such system configuration difficulties: under non-standard measurement conditions when it is necessary to adapt system elements to environmental conditions were analyzed. To ensure the possibility of optimal  measurement system parameters search, the measurement system configuration quality quantitative estimates based on object three-dimensional geometry measurement results and intermediate measurement data were introduced. The measurement system configuration quality quantitative estimates calculation algorithms were developed. The software package, consisting of two programs, that allows to process and visualize object three-dimensional geometry measurement results and intermediate measurement data and to display measurement system operation quality quantitative estimates was created. The software package was tested on the ice three-dimensional measurement system that is used in the icing of reduced wind generator functional elements effects studying stand. The measurement system was configured for the measurement volume with the characteristic size of 85×67×25 mm. The modulation signal frequency and the optical system parameters were optimized: the optical radiation source and receiver relative location, their focal lengths, the receiver exposure time and analog signal gain value. The three-dimensional geometry measurement error of 9 μm was achieved. The three-dimensional object geometry measurement system based on the phase triangulation and binary Grey codes methods configuration possibility with the help of the developed software package was confirmed. The software package can be used in spheres where it is necessary to adapt parameters of the three-dimensional geometry measurement system based on the phase triangulation and binary Grey codes methods to environmental conditions, for example, wind and hydropower, hot metallurgy.

In order to improve the accuracy of the dynamic goniometer, the influence of its bearing on the measurement error was studied. The spectral characteristics of the random error of two dynamic goniometers with the same optical angle encoders and different bearings, aerostatic and angular contact ball bearings, are studied. It is shown that the use of a ball bearing in the goniometer leads to non-stationarity of the random error of angular measurements. Using wavelet analysis and Allan variation, the random error of the dynamic goniometer is analyzed, the sources of nonstationarity are identified, and its potential accuracy is determined. It has been established that the use of an aerostatic bearing makes it possible to increase the accuracy of a dynamic goniometer and bring its value closer to the accuracy of a static goniometer, in which the influence of the bearing assembly is minimized. The results obtained are of interest to users and developers of dynamic goniometers.

The problem of evaluation of metrological characteristics of prototypes and virtual measuring instruments is considered. In the article are presented results of a study of the measurement error of two DC voltmeters – a device on a prototyping board and a virtual voltmeter. The prototype is implemented on an ATmega8 microcontroller with a 4-bit indicator, the virtual device is developed in the Proteus environment and completely repeats the schematic diagram of the prototype. The GW Instek GPC power supply and the VOLTCRAFT MXD laboratory multimeter were used as reference tools. Estimates of the absolute and relative error of the prototype and the virtual device in the range of 0–6 V. A high level of error in the range up to 1 V was determined for the prototype. A comparative analysis of the results of error estimation of the two studied devices was carried out. The results obtained will be useful in planning and conducting similar studies of other types of measuring instruments in scientific and educational organizations.

The problem of insufficient accuracy, informativeness and efficiency of recognition of the structure and composition of inhomogeneous surface layers of thin metal-oxide heterostructures during non-destructive testing by spectral optical methods is considered. It is noted that the currently available methods of studying such layers, as a rule, are destructive in nature. To improve the accuracy, informativeness and efficiency of non-destructive testing of the chemical composition of thin metal-oxide heterostructures, a method of phase-spectral ellipsometry has been developed. In this method, the results of ellipsometric measurements of reflected radiation of various wavelengths are used to determine the distribution function of the complex refractive index of an inhomogeneous surface layer along its depth. To implement the proposed method, a phase spectral ellipsometer circuit with a wavelength as a control signal of the feedback channel has been created. The method of phase-spectral ellipsometry is used to control the distribution of chemical composition over the depth of thin metal-oxide heterostructures on the surface of stainless steel Cr18-Ni10-Ti, oxidized at low temperatures and oxygen pressures. When comparing the obtained results with independent auger profiling data of oxidized samples, it was found that the distribution of the chemical composition over the depth of the oxide corresponds to independent Auger data. It is shown that the method of phase spectral ellipsometry makes it possible to clearly separate and identify various oxidized forms of the alloy. The presented method can be used for non-destructive and especially in-situ study of the distribution of chemical composition over the depth of ultrathin inhomogeneous surface oxides.

The problem of the rational selection of measurement procedure for determining the chloride-ion in concrete and reinforced concrete structures, the content of which in concrete affects the rate of rebar corrosion, is considered. A review of standardized and validated measurement procedures for determining the chloride-ion in concrete and reinforced concrete structures is given. The results of a comparative analysis of measurement procedures for construction industry based on argentometric, phototurbidimetric and potentiometric (ionometric) methods are presented on the basis of criteria “Purpose and scope of the measurement procedure”, “Analysis method”, “Measuring instruments and reagents”, “Preparation for analysis”, “Analysis procedure”, “Processing the measurement results”. An order of rational measurement procedure selection in construction companies on the basis of complex quality index (cost price) calculation is proposed. Application of a measurement procedure based on the argentometric method (for mass fraction of chloride-ion in concrete from 0.5 %) and a measurement procedure based on the potentiometric method (for mass fraction of chloride-ion in concrete from 0.05 %) with the use of estimated cost price has been argued. This proposed approach to the selection of a rational measurement procedure can be used in assessing the compliance of construction materials with the requirements of norms and regulations, as well as the Technical Regulation on the Safety of Buildings and Structures.