The main stages of modernization of the State primary standard of the unit of length are described. The structure of the standard, new laser sources and units are described. The results of research of metrological characteristics of lasers at wavelengths of 633 and 532 nm are presented. The research were carried out by the He–Ne/ආ₂ stabilized laser, the unit for measuring the frequency difference of laser radiation sources and the complex of equipment for measurement of laser frequency (wavelength in vacuum) in the wavelength range from 500 to 1050 nm (comb generator). As a result of the research, the main sources of the components of residual systematic error and standard uncertainty (type B), standard deviation and standard uncertainty (type A). The comparative analysis of the metrological characteristics of GET 2-2010 and GET 2-2021 are also given. Thus, it became possible to realize the unit of length at the wavelength of 633 nm with standard deviation of 1,6·10^–12 and at the wavelength of 532 nm with standard deviation of 1,3·10^–12, and the range of transferring of the unit of length to laser radiation sources and other modern high-precision measuring systems has been expanded. The State primary standard of the unit of length GET 2-2021 has been successfully tested and approved by the order of Rosstandart.

High precision strain gauge balances are used for the testing of the arcraft models in wind tunnels. The precision of the strain gauge balances depends on the balance temperature. The basic physical factors affecting the balance readings with temperature variation are reviewed and estimated. We considered the effect of static component of the temperature error on the readings of the strain gauge balance. A method of application of temperature corrections to the balance readings by means of the temperature sensitivity coefficient is described. We developed the method of determining coefficient of temperature sensitivity of balance components during a fulfilment of the test campaign in a wind tunnel. The experimental equipment and the experimental investigations carried out are described. The experimental results of determining the effect of the static temperature component on the readings of six-component balance are presented. Characteristic value of the sensitivity coefficient was found to be approximately 0.04 %/°C. It is shown that the standard deviation of the balance readings exceeds the balance calibration standard deviation when the balance temperature varies more than 3–4 °C. The temperature systematic error has to be excluded from results of the balance measurement in the form of correction to the sensitivity coefficient or electrical signal. The method was verified by the results of measurement of the weight of the aircraft model and the weight of the metric parts of the strain-gauge balance’s longitudinal and normal force components in the wind tunnel.

When developing measuring instruments, taking into account the diversity of signals and factors affecting errors, the actual problem is the choice of the method of discrete wavelet filtering of measuring signals. The results of the development of an algorithm for choosing a discrete wavelet filtering method taking into account the nature of the measuring signal are presented. The three most common methods of discrete wavelet filtering are investigated, followed by a comparative analysis of twenty types of measurement signals. The following wavelet filtering methods are analyzed: with a common threshold for all levels of decomposition; without a threshold with a simple zeroing of the detail ratios until the minimum root-mean-square error of filtering the measurement signals is reached; with a universal threshold for the detail ratios at each decomposition level. We examined twenty types of measurement signals from the PyWavelets library, to which we added uncorrelated normally distributed noise with zero expectation and a given standard deviation. Method comparison criteria are defined for noisy signals before filtering and for filtered signals. The difference in signal-to-noise ratios, the difference in entropy errors, the rms filtering error, and the function of the measuring signal were used as criteria. For each filtering method, the comparison criteria are determined from the condition of the minimum root-mean-square error introduced by noise into the measuring signal of this type. When choosing a method, both energy and informational characteristics of signals were taken into account. The filtering parameters are determined by round-robin search to achieve the minimum root-meansquare filtering error. The proposed algorithm makes it possible to determine the most effective methods of discrete wavelet filtering, depending on the nature of the measuring signal. In this case, the developer simultaneously solves two problems: the choice of the filtration method and the determination of the filtration parameters.

A statistical analysis of errors in tomographic measurements of polarization-entangled biphoton states generated by sources based on the effect of spontaneous parametric down-conversion is carried out. The level of quantum fluctuations in the coincidence scheme, which is an unavoidable source of error in tomographic measurements, is analyzed in detail. A quantum tomograph was used to measure the density matrix of the quantum polarization state of biphotons in the Bell polarization state. The errors caused by quantum fluctuations are compared with the instrumental errors. It is shown that there are no obstacles to creating a tomographic metrological stand intended for characterizing SPDC-sources generating polarization-entangled biphotons.

The structure, principle of operation and metrological performance of rubidium fountain developed at VNIIFTRI are presented. The preliminary uncertainty budget of this standard is the main goal of this research. The physical effects that cause the largest shifts of the measured frequency: quadratic Zeeman effect, blackbody radiation effect, gravitational redshift, cavity pulling effect are considered. Its frequency stability is and evaluated frequency uncertainty is less than 2·10^–16. Those performances are at the level of the best rubidium fountain standards developed across the world. Those results are relevant for the time and frequency metrology and for timescales.

The problem of search and verification of criteria of sampling of the transducer of certain type depending on prospective entrance affecting - criteria of usability of the impulse (dynamic) pressure transducer, based on its dynamic characteristics is observed. Thus similar transducers are widely used at research fluid-gas-dynamics processes. Existing rules in the field of measurement of pulsing pressures are systematized. Dynamic characteristics of impulse pressure transducers of several types are experimentally investigated, their transfer functions are gained and responses of transducers to set entrance affecting are simulated. The experimental method of reception of a transfer function with use of a pneumatic shock tube and applied mathematical software packages is offered. Absence of uniform universal criterion of usability of the impulse pressure transducer depending on prospective entrance affecting is confirmed. Results of research can be claimed at a choice of necessary type of the transducer at measurement of impulse (dynamic) pressure in various tasks of a science and technics.

Possibilities of increasing the accuracy of non-contact temperature measurements are investigated. A method of surface pyrometry is proposed, in which the errors caused by the background radiation of third-party emitters are reduced with the help of reflecting screens. Temperature measurements are carried out with a serial narrow-angle pyrometer, sighted at the surface through a hole in the cavity of the screen made of fibrous heat-resistant material. The results of a series of experiments substantiating the content and parameters of the operations of the measurement method are presented. In particular, a decrease in the actual temperature of the measured surface by approximately 20–25 °C was noted when uncooled screens were introduced into the chamber of the thermal unit before each measurement. Qualitative results of measuring the surface temperature were obtained under conditions when the screens remained in the working space of the furnace between measurements, and the temperature leveling of holding the screens in positions on the surface before and during the measurement was carried out for 1–2 minutes. The results of industrial tests of the measurement method are described. The measurement method can be used for technological measurements directly on high-temperature units or for periodic testing and determination of corrections to the readings of stationary pyrometers.

An effective method for detecting surface defects by magnetic field anomalies occurring over cracks, chips and crevices of angular elements of complex-profile parts made of ferromagnetic materials is considered. The method is based on the spectral analysis of the signal of a tangentially oriented vibration-induction transducer. The theoretical justification of the amplitude-phase method of analysis and research based on mathematical modeling of the signal of a vibration-inductive transducer in the form of a trigonometric series is given. The results of recording and analyzing the distribution of the magnetic field strength, as well as the amplitude-phase spectrum of the signal of a vibration-inductive transducer along a surface with an involute and threaded profi les are presented. The results were obtained on control samples of a gear wheel, a threaded stud and a bolt with artificial defects. The conditions for detecting defects based on the results of measuring the amplitude and phase of the first two harmonics of the signal of a vibrationinductive transducer are formulated. The parameters of the control scheme of the involute profiles and threads with the values of the module and the step of the order of several millimeters, providing the possibility of automating the control process with a satisfactory signal/background ratio, are determined. The method is designed to control the continuity of parts containing profiled surface areas (galtel transitions, involute, threaded and spline profiles, etc.).

The influence of the parameters of the construction of the spatial-dependence matrices on textural features in the tasks of recognizing bone marrow cells in information and measurement systems for the diagnosis of acute leukemia is studied. Bone marrow preparations were obtained from patients with B- and T-cell acute lymphoblastic leukemias. 100 images of blast cells of B- and T-types were involved. Five textural features are considered – energy, inertia moment, local uniformity, maximum probability, entropy. The features were calculated on the basis of the spatial dependence matrices. The type of the color components of the RGB color image model, the adjacency distance and the direction of adjacency were analyzed as variable parameters when constructing the specified matrices. For a given sample of images of blast cells of type T and B a range of adjacency distances from 1 to 11 pixels was revealed, in which the greatest change in the values of texture features is observed. For different types of signs the change ranged from 20 % to 1700 %. The maximum information content among the studied texture features was obtained for the G-component of a color image in the texture feature “local uniformity” (information content coefficient 0.48) with an adjacency distance equal to one pixel. For practical application, it is recommended to use four directions of adjacency when constructing spatial adjacency matrices. The obtained results are important for specialists working in the field of designing information and measurement systems of oncohematology (diagnostics of dangerous oncological diseases – acute leukemias).

The article is dedicated to the image standardization problem in digital microscopy. Color reproducibility in microscopic images is of great importance as this can lead to therapeutic errors in image interpretation. Color reproducibility in digital microscopy systems with various hardware can be ensured with color calibration using a special slide. The proposed requirements for color slide development are based on the analysis of the literature. A color measure prototype consisting of 97 fields of colored glass was developed and manufactured. Color chromaticity coordinates in CIE XYZ color space were calculated from experimentally determined spectral transmitted radiation distributions. A comparative study of the proposed color slide prototype and existing color slides gamuts according to the most frequently used histological dyes chromaticity coordinates have been carried out.

The advantages and disadvantages of the gas sensors for measurement of content of the toxic substances in a working zone are reviewed. The main standarts and normative documents setting the requirements for instrument for measuring of content of the harmful substances in a working zone air are considered. Experimental setup for research of the amperometric sensors characteristics, measurement procedure and experimental results are described. Comparative analysis of the characteristics of sensors produced by various manufacturers are presented. Recommendations are given on the practical use of the obtained date for development of the measuring instruments satisfying the requirements of the domestic regulations.